Programs & Examples On #Multivalue

The term "multivalue" refers to a nested data structure where a data column in a database table can contain multiple levels of nested columns.

org.springframework.web.client.HttpClientErrorException: 400 Bad Request

This is what worked for me. Issue is earlier I didn't set Content Type(header) when I used exchange method.

MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();
map.add("param1", "123");
map.add("param2", "456");
map.add("param3", "789");
map.add("param4", "123");
map.add("param5", "456");

HttpHeaders headers = new HttpHeaders();

final HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<MultiValueMap<String, String>>(map ,
JSONObject jsonObject = null;

try {
    RestTemplate restTemplate = new RestTemplate();
    ResponseEntity<String> responseEntity =
            "https://url", HttpMethod.POST, entity,

    if (responseEntity.getStatusCode() == HttpStatus.CREATED) {
        try {
            jsonObject = new JSONObject(responseEntity.getBody());
        } catch (JSONException e) {
            throw new RuntimeException("JSONException occurred");
  } catch (final HttpClientErrorException httpClientErrorException) {
        throw new ExternalCallBadRequestException();
  } catch (HttpServerErrorException httpServerErrorException) {
        throw new ExternalCallServerErrorException(httpServerErrorException);
  } catch (Exception exception) {
        throw new ExternalCallServerErrorException(exception);

ExternalCallBadRequestException and ExternalCallServerErrorException are the custom exceptions here.

Note: Remember HttpClientErrorException is thrown when a 4xx error is received. So if the request you send is wrong either setting header or sending wrong data, you could receive this exception.

Content type 'application/x-www-form-urlencoded;charset=UTF-8' not supported for @RequestBody MultiValueMap

In Spring 5

@PostMapping( "some/request/path" )
public void someControllerMethod( @RequestParam MultiValueMap body ) {

    // import org.springframework.util.MultiValueMap;

    String datax = (String) body .getFirst("datax");

How to autowire RestTemplate using annotations

You can add the method below to your class for providing a default implementation of RestTemplate:

public RestTemplate restTemplate() {
    return new RestTemplate();

Multipart File Upload Using Spring Rest Template + Spring Web MVC

A correct file upload would like this:

HTTP header:

Content-Type: multipart/form-data; boundary=ABCDEFGHIJKLMNOPQ

Http body:


Content-Disposition: form-data; name="file"; filename="my.txt"

Content-Type: application/octet-stream

Content-Length: ...

<...file data in base 64...>


and code is like this:

public void uploadFile(File file) {
        try {
            RestTemplate restTemplate = new RestTemplate();
            String url = "http://localhost:8080/file/user/upload";
            HttpMethod requestMethod = HttpMethod.POST;

            HttpHeaders headers = new HttpHeaders();

            MultiValueMap<String, String> fileMap = new LinkedMultiValueMap<>();
            ContentDisposition contentDisposition = ContentDisposition

            fileMap.add(HttpHeaders.CONTENT_DISPOSITION, contentDisposition.toString());
            HttpEntity<byte[]> fileEntity = new HttpEntity<>(Files.readAllBytes(file.toPath()), fileMap);

            MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
            body.add("file", fileEntity);

            HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);

            ResponseEntity<String> response =, requestMethod, requestEntity, String.class);

            System.out.println("file upload status code: " + response.getStatusCode());

        } catch (IOException e) {


Multipart File upload Spring Boot

@RequestBody MultipartFile[] submissions

should be

@RequestParam("file") MultipartFile[] submissions

The files are not the request body, they are part of it and there is no built-in HttpMessageConverter that can convert the request to an array of MultiPartFile.

You can also replace HttpServletRequest with MultipartHttpServletRequest, which gives you access to the headers of the individual parts.

How to set an "Accept:" header on Spring RestTemplate request?

You could set an interceptor "ClientHttpRequestInterceptor" in your RestTemplate to avoid setting the header every time you send a request.

public class HeaderRequestInterceptor implements ClientHttpRequestInterceptor {

        private final String headerName;

        private final String headerValue;

        public HeaderRequestInterceptor(String headerName, String headerValue) {
            this.headerName = headerName;
            this.headerValue = headerValue;

        public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
            request.getHeaders().set(headerName, headerValue);
            return execution.execute(request, body);


List<ClientHttpRequestInterceptor> interceptors = new ArrayList<ClientHttpRequestInterceptor>();
interceptors.add(new HeaderRequestInterceptor("Accept", MediaType.APPLICATION_JSON_VALUE));

RestTemplate restTemplate = new RestTemplate();

How to add Headers on RESTful call using Jersey Client API

String sBodys="Body";
HashMap<String,String> headers= new HashMap<>();
Client c = Client.create();
WebResource resource = c.resource("http://consulta/rs");
WebResource.Builder builder = resource.accept(MediaType.APPLICATION_JSON);
      LOGGER.debug("se setean los headers");
      for (Map.Entry<String, String> entry : headers.entrySet()) {
          String key = entry.getKey();
          String value = entry.getValue();
          LOGGER.debug("key: "+entry.getKey());
          LOGGER.debug("value: "+entry.getValue());
          builder.header(key, value);
ClientResponse response =,sBodys);

HTTP get with headers using RestTemplate

Take a look at the JavaDoc for RestTemplate.

There is the corresponding getForObject methods that are the HTTP GET equivalents of postForObject, but they doesn't appear to fulfil your requirements of "GET with headers", as there is no way to specify headers on any of the calls.

Looking at the JavaDoc, no method that is HTTP GET specific allows you to also provide header information. There are alternatives though, one of which you have found and are using. The exchange methods allow you to provide an HttpEntity object representing the details of the request (including headers). The execute methods allow you to specify a RequestCallback from which you can add the headers upon its invocation.

Uri not Absolute exception getting while calling Restful Webservice

The problem is likely that you are calling URLEncoder.encode() on something that already is a URI.

How to pass multiple values to single parameter in stored procedure

I spent time finding a proper way. This may be useful for others.

Create a UDF and refer in the query -

Jersey client: How to add a list as query parameter

@GET does support List of Strings

Java : 1.7
Jersey version : 1.9




// receive List of Strings
public Response receiveListOfStrings(@QueryParam("list") final List<String> list){"receieved list of size="+list.size());
    return Response.ok().build();

Jersey testcase

public void testReceiveListOfStrings() throws Exception {
    WebResource webResource = resource();
    ClientResponse responseMsg = webResource.path("/v1/test/receiveListOfStrings")
            .queryParam("list", "one")
            .queryParam("list", "two")
            .queryParam("list", "three")
    Assert.assertEquals(200, responseMsg.getStatus());

django MultiValueDictKeyError error, how do I deal with it

First check if the request object have the 'is_private' key parameter. Most of the case's this MultiValueDictKeyError occurred for missing key in the dictionary-like request object. Because dictionary is an unordered key, value pair “associative memories” or “associative arrays”

In another word. request.GET or request.POST is a dictionary-like object containing all request parameters. This is specific to Django.

The method get() returns a value for the given key if key is in the dictionary. If key is not available then returns default value None.

You can handle this error by putting :

is_private = request.POST.get('is_private', False);

How to create a property for a List<T>

Either specify the type of T, or if you want to make it generic, you'll need to make the parent class generic.

public class MyClass<T>

Sending Multipart File as POST parameters with RestTemplate requests

You have to add the FormHttpMessageConverter to your applicationContext.xml to be able to post multipart files.

<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
    <property name="messageConverters">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter" />
            <bean class="org.springframework.http.converter.FormHttpMessageConverter" />

See for examples.

Select All as default value for Multivalue parameter

Try setting the parameters' "default value" to use the same query as the "available values". In effect it provides every single "available value" as a "default value" and the "Select All" option is automatically checked.

VBA EXCEL Multiple Nested FOR Loops that Set two variable for expression

I can't get to your google docs file at the moment but there are some issues with your code that I will try to address while answering

Sub stituterangersNEW()
Dim t As Range
Dim x As Range
Dim dify As Boolean
Dim difx As Boolean
Dim time2 As Date
Dim time1 As Date

    'You said time1 doesn't change, so I left it in a singe cell.
    'If that is not correct, you will have to play with this some more.
    time1 = Range("A6").Value

    'Looping through each of our output cells.
    For Each t In Range("B7:E9") 'Change these to match your real ranges.

        'Looping through each departure date/time.
        '(Only one row in your example. This can be adjusted if needed.)
        For Each x In Range("B2:E2") 'Change these to match your real ranges.
            'Check to see if our dep time corresponds to
            'the matching column in our output
            If t.Column = x.Column Then
                'If it does, then check to see what our time value is
                If x > 0 Then
                    time2 = x.Value
                    'Apply the change to the output cell.
                    t.Value = time1 - time2
                    'Exit out of this loop and move to the next output cell.
                    Exit For
                End If
            End If
            'If the columns don't match, or the x value is not a time
            'then we'll move to the next dep time (x)
        Next x
    Next t

End Sub


I changed you worksheet to play with (see above for the new Sub). This probably does not suite your needs directly, but hopefully it will demonstrate the conept behind what I think you want to do. Please keep in mind that this code does not follow all the coding best preactices I would recommend (e.g. validating the time is actually a TIME and not some random other data type).

     A                      B                   C                   D                  E
1    LOAD_NUMBER            1                   2                   3                  4
2    DEPARTURE_TIME_DATE    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 20:00                
4    Dry_Refrig 7585.1  0   10099.8 16700
6    1/4/2012 19:30

Using the sub I got this output:

    A           B             C             D             E
7   Friday      1272:00:00    1272:00:00    1272:00:00    1271:30:00
8   Saturday    1272:00:00    1272:00:00    1272:00:00    1271:30:00
9   Thursday    1272:00:00    1272:00:00    1272:00:00    1271:30:00

How to empty a file using Python

Alternate form of the answer by @rumpel

with open(filename, 'w'): pass

How can I get the current page name in WordPress?

Within the WordPress Loop:

if ( have_posts() ) : while ( have_posts() ) : the_post();
echo get_the_title();
endwhile; endif;

This will show you the current page title.

For reference: get_the_title()

How to get disk capacity and free space of remote computer

Much simpler solution:

Get-PSDrive C | Select-Object Used,Free

and for remote computers (needs Powershell Remoting)

Invoke-Command -ComputerName SRV2 {Get-PSDrive C} | Select-Object PSComputerName,Used,Free

Pandas: rolling mean by time interval

visualize the rolling averages to see if it makes sense. I don't understand why sum was used when the rolling average was requested.



 fig, axs = plt.subplots(figsize=(5,10))
 df.plot(x='enddate', ax=axs)

 print("The larger the window coefficient the smoother the line will appear")
 print('The min_periods is the minimum number of observations in the window required to have a value')


MySQL Error 1153 - Got a packet bigger than 'max_allowed_packet' bytes

Re my.cnf on Mac OS X when using MySQL from the dmg package distribution

By default, my.cnf is nowhere to be found.

You need to copy one of /usr/local/mysql/support-files/my*.cnf to /etc/my.cnf and restart mysqld. (Which you can do in the MySQL preference pane if you installed it.)

.datepicker('setdate') issues, in jQuery

If you would like to support really old browsers you should parse the date string, since using the ISO8601 date format with the Date constructor is not supported pre IE9:

var queryDate = '2009-11-01',
    dateParts = queryDate.match(/(\d+)/g)
    realDate = new Date(dateParts[0], dateParts[1] - 1, dateParts[2]);  
                                    // months are 0-based!
// For >= IE9
var realDate = new Date('2009-11-01');  

$('#datePicker').datepicker({ dateFormat: 'yy-mm-dd' }); // format to show
$('#datePicker').datepicker('setDate', realDate);

Check the above example here.

Apply CSS styles to an element depending on its child elements

Basically, no. The following would be what you were after in theory:

div.a < div { border: solid 3px red; }

Unfortunately it doesn't exist.

There are a few write-ups along the lines of "why the hell not". A well fleshed out one by Shaun Inman is pretty good:

C++ Loop through Map

As @Vlad from Moscow says, Take into account that value_type for std::map is defined the following way:

typedef pair<const Key, T> value_type

This then means that if you wish to replace the keyword auto with a more explicit type specifier, then you could this;

for ( const pair<const string, int> &p : table ) {
   std::cout << p.first << '\t' << p.second << std::endl;

Just for understanding what auto will translate to in this case.

How to cherry-pick multiple commits

Here's a script that will allow you to cherry-pick multiple commits in a row simply by telling the script which source and target branches for the cherry picks and the number of commits:

To cherry-pick from your branch to master (uses the current branch as source):

./ -m

To cherry-pick the latest 5 commits from your 6.19.x branch to master:

./ -c 5 -s 6.19.x -t master

Jquery Open in new Tab (_blank)

Replace this line:

$(this).target = "_blank";


$( this ).attr( 'target', '_blank' );

That will set its HREF to _blank.

How to write an inline IF statement in JavaScript?

There is a ternary operator, like this:

var c = (a < b) ? "a is less than b"  : "a is not less than b";

Running windows shell commands with python

The newer subprocess.check_output and similar commands are supposed to replace os.system. See this page for details. While I can't test this on Windows (because I don't have access to any Windows machines), the following should work:

from subprocess import check_output
check_output("dir C:", shell=True)

check_output returns a string of the output from your command. Alternatively, just runs the command and returns the status of the command (usually 0 if everything is okay).

Also note that, in python 3, that string output is now bytes output. If you want to change this into a string, you need something like

from subprocess import check_output
check_output("dir C:", shell=True).decode()

If necessary, you can tell it the kind of encoding your program outputs. The default is utf-8, which typically works fine, but other standard options are here.

Also note that @bluescorpion says in the comments that Windows 10 needs a trailing backslash, as in check_output("dir C:\\", shell=True). The double backslash is needed because \ is a special character in python, so it has to be escaped. (Also note that even prefixing the string with r doesn't help if \ is the very last character of the string — r"dir C:\" is a syntax error, though r"dir C:\ " is not.)

SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range value

This error occurred for me because i was trying to store the minimum date and time in a column using inline queries directly from C# code.

The date variable was set to 01/01/0001 12:00:00 AM in the code given the fact that DateTime in C# is initialized with this date and time if not set elsewise. And the least possible date allowed in the MS-SQL 2008 datetime datatype is 1753-01-01 12:00:00 AM.

I changed the date from the code and set it to 01/01/1900 and no errors were reported further.

How do I prompt a user for confirmation in bash script?

echo Please, enter your name
read NAME
echo "Hi $NAME!"
if [ "x$NAME" = "xyes" ] ; then
 # do something

I s a short script to read in bash and echo back results.

How to create a HTML Cancel button that redirects to a URL

There are a few problems here.

First of all, there is no such thing as <button type="cancel">, so it is treated as just a <button>. This means that your form will be submitted, instead of the button taking you elsewhere.

Second, javascript: is only needed in href or action attributes, where a URL is expected, to designate JavaScript code. Inside onclick, where JavaScript is already expected, it merely acts as a label and serves no real purpose.

Finally, it's just generally better design to have a cancel link rather than a cancel button. So you can just do this:

<a href="">Cancel</a>

With CSS you can even make it look the same as a button, but with this HTML there is absolutely no confusion as to what it is supposed to do.

How to find a whole word in a String in java

Got a way to match Exact word from String in Android:

String full = "Hello World. How are you ?";

String one = "Hell";
String two = "Hello";
String three = "are";
String four = "ar";

boolean is1 = isContainExactWord(full, one);
boolean is2 = isContainExactWord(full, two);
boolean is3 = isContainExactWord(full, three);
boolean is4 = isContainExactWord(full, four);

Log.i("Contains Result", is1+"-"+is2+"-"+is3+"-"+is4);

Result: false-true-true-false

Function for match word:

private boolean isContainExactWord(String fullString, String partWord){
    String pattern = "\\b"+partWord+"\\b";
    Pattern p=Pattern.compile(pattern);
    Matcher m=p.matcher(fullString);
    return m.find();


Getting the folder name from a path

Try this:

string filename = @"C:/folder1/folder2/file.txt";
string FolderName = new DirectoryInfo(System.IO.Path.GetDirectoryName(filename)).Name;

Using external images for CSS custom cursors

I would put this as a comment, but I don't have the rep for it. What Josh Crozier answered is correct, but for IE .cur and .ani are the only supported formats for this. So you should probably have a fallback just in case:

.test {
    cursor:url(""), url(foo.cur), auto;

How to set up tmux so that it starts up with specified windows opened?

You can source different sessions from your .tmux.conf like so:

# initialize sessions
bind S source-file ~/.tmux/session1 
bind s source-file ~/.tmux/session2

And then format the sessions as you require:

new  -s SessionName -n WindowName Command
neww -n foo/bar foo
splitw -v -p 50 -t 0 bar
selectw -t 1 
selectp -t 0

This would open 2 windows, the second of which would be named foo/bar and would be split vertically in half (50%) with foo running above bar. Focus would be in window 2 (foo/bar), top pane (foo).

You can then start your preferred tmux session (in this case, session1) with PrefixShifts

Create XML file using java

I am providing an answer from my own blog. Hope this will help.

What will be output?

Following XML file named users.xml will be created.

<?xml version="1.0" encoding="UTF-8" standalone="no" ?> 
    <user uid="1">
        <email>[email protected]</email>


Basic steps, in order to create an XML File with a DOM Parser, are:

  1. Create a DocumentBuilder instance.

  2. Create a Document from the above DocumentBuilder.

  3. Create the elements you want using the Element class and its appendChild method.

  4. Create a new Transformer instance and a new DOMSource instance.

  5. Create a new StreamResult to the output stream you want to use.

  6. Use transform method to write the DOM object to the output stream.


package com.example.TestApp;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class CreateXMLFileJava {

 public static void main(String[] args) throws ParserConfigurationException, 
     // 1.Create a DocumentBuilder instance
    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder dbuilder = dbFactory.newDocumentBuilder();

    // 2. Create a Document from the above DocumentBuilder.
    Document document = dbuilder.newDocument();

    // 3. Create the elements you want using the Element class and its appendChild method.   

   // root element
    Element users = document.createElement("users");

    // child element
    Element user = document.createElement("user");

    // Attribute of child element
    user.setAttribute("uid", "1");   

    // firstname Element
    Element firstName = document.createElement("firstName");

    // lastName element
    Element lastName = document.createElement("lastName");

    // email element
    Element email = document.createElement("email");
    email.appendChild(document.createTextNode("[email protected]"));

    // write content into xml file   

    // 4. Create a new Transformer instance and a new DOMSource instance.
   TransformerFactory transformerFactory = TransformerFactory.newInstance();
   Transformer transformer = transformerFactory.newTransformer();
   DOMSource source = new DOMSource(document);

   // 5. Create a new StreamResult to the output stream you want to use.
   StreamResult result = new StreamResult(new File("/Users/admin/Desktop/users.xml"));
   // StreamResult result = new StreamResult(System.out); // to print on console

   // 6. Use transform method to write the DOM object to the output stream.
   transformer.transform(source, result);  

   System.out.println("File created successfully");


<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  <user uid="1">
     <email>[email protected]</email>

The ScriptManager must appear before any controls that need it

The script manager must be put onto the page before it is used. This would be directly on the page itself, or alternatively, if you are using them, on the Master Page.

The markup would be;

 <asp:ScriptManager ID="ScriptManager1" runat="server" LoadScriptsBeforeUI="true"
            EnablePartialRendering="true" />

How to check if C string is empty

First replace the scanf() with fgets() ...

do {
    if (!fgets(url, sizeof url, stdin)) /* error */;
    /* ... */
} while (*url != '\n');

Android: Use a SWITCH statement with setOnClickListener/onClick for more than 1 button?

And there's yet a third option. In your onCreate() method, find all the button views that you have and save them as class data members. You can then cascade a group of if-else statements to find which is which. It's kind of messy, but it's a must if you don't know the ID of the buttons (which can be complicated if you are generating buttons in java code).

public void onClick(View v) {
    if (v == m_myCards) {
        Intent intent = new Intent(this, MyCards.class);
    else if (v == m_exit) {
    else if (v == m_back) {

Another nice thing about this technique is that it's flexible and quick (no having to parse IDs). The bad thing is that you need to keep the widgets in memory.

Don't know which method is better.

How to avoid the "Circular view path" exception with Spring MVC test

If you are using Spring Boot, then add thymeleaf dependency into your pom.xml:


TSQL Default Minimum DateTime

Unless you are doing a DB to track historical times more than a century ago, using

Modified datetime DEFAULT ((0)) 

is perfectly safe and sound and allows more elegant queries than '1753-01-01' and more efficient queries than NULL.

However, since first Modified datetime is the time at which the record was inserted, you can use:


which avoids the whole issue and makes your inserts easier and safer - as in you don't insert it at all and SQL does the housework :-)

With that in place you can still have elegant and fast queries by using 0 as a practical minimum since it's guranteed to always be lower than any insert-generated GETUTCDATE().

How do files get into the External Dependencies in Visual Studio C++?

The External Dependencies folder is populated by IntelliSense: the contents of the folder do not affect the build at all (you can in fact disable the folder in the UI).

You need to actually include the header (using a #include directive) to use it. Depending on what that header is, you may also need to add its containing folder to the "Additional Include Directories" property and you may need to add additional libraries and library folders to the linker options; you can set all of these in the project properties (right click the project, select Properties). You should compare the properties with those of the project that does build to determine what you need to add.

How to connect wireless network adapter to VMWare workstation?

  1. Add a local loop network in your normal PC (search google how to)
  2. Click start -> type "ncpa.cpl" hit enter to open network connections.
  3. While pressing Ctrl key, select both your wireless and recently created local loop network. right click on it and create the bridge.
  4. Now in virtual network editor in vmware, select the network with type "Bridged" and change Bridged to option to the recently created bridge.

You will then have access to network via wifi card.

TypeError: 'NoneType' object is not iterable in Python

It means the value of data is None.

restrict edittext to single line

You must add this line in your EditText in xml:


How to make "if not true condition"?


if ! grep -q sysa /etc/passwd ; then

grep returns true if it finds the search target, and false if it doesn't.

So NOT false == true.

if evaluation in shells are designed to be very flexible, and many times doesn't require chains of commands (as you have written).

Also, looking at your code as is, your use of the $( ... ) form of cmd-substitution is to be commended, but think about what is coming out of the process. Try echo $(cat /etc/passwd | grep "sysa") to see what I mean. You can take that further by using the -c (count) option to grep and then do if ! [ $(grep -c "sysa" /etc/passwd) -eq 0 ] ; then which works but is rather old school.

BUT, you could use the newest shell features (arithmetic evaluation) like

if ! (( $(grep -c "sysa" /etc/passwd) == 0 )) ; then ...`

which also gives you the benefit of using the c-lang based comparison operators, ==,<,>,>=,<=,% and maybe a few others.

In this case, per a comment by Orwellophile, the arithmetic evaluation can be pared down even further, like

if ! (( $(grep -c "sysa" /etc/passwd) )) ; then ....


if (( ! $(grep -c "sysa" /etc/passwd) )) ; then ....

Finally, there is an award called the Useless Use of Cat (UUOC). :-) Some people will jump up and down and cry gothca! I'll just say that grep can take a file name on its cmd-line, so why invoke extra processes and pipe constructions when you don't have to? ;-)

I hope this helps.

Set value of hidden input with jquery

This worked for me:


How to write text on a image in windows using python opencv2

Here's the code with parameter labels

def draw_text(self, frame, text, x, y, color=BGR_COMMON['green'], thickness=1.3, size=0.3,):
    if x is not None and y is not None:
            frame, text, (int(x), int(y)), cv2.FONT_HERSHEY_SIMPLEX, size, color, thickness)

For font name please see another answer in this thread.

Excerpt from answer by @Roeffus

This is indeed a bit of an annoying problem. For python 2.x.x you use:

cv2.CV_FONT_HERSHEY_SIMPLEX and for Python 3.x.x:


For more see this

send checkbox value in PHP form

if(isset($_POST["newsletter"]) && $_POST["newsletter"] == "newsletter"){

Replace tabs with spaces in vim


set expandtab

for soft tabs.

To fix pre-existing tabs:

:%s/\t/  /g

I used two spaces since you already set your tabstop to 2 spaces.

{"<user xmlns=''> was not expected.} Deserializing Twitter XML

As John Saunders says, check if the class/property names matches the capital casing of your XML. If this isn't the case, the problem will also occur.

Multiplication on command line terminal

A simple shell function (no sed needed) should do the trick of interpreting '5X5'

$ function calc { bc -l <<< ${@//[xX]/*}; };
$ calc 5X5
$ calc 5x5
$ calc '5*5'

How to retrieve the last autoincremented ID from a SQLite table?

With SQL Server you'd SELECT SCOPE_IDENTITY() to get the last identity value for the current process.

With SQlite, it looks like for an autoincrement you would do

SELECT last_insert_rowid()

immediately after your insert.[email protected]/msg09429.html

In answer to your comment to get this value you would want to use SQL or OleDb code like:

using (SqlConnection conn = new SqlConnection(connString))
    string sql = "SELECT last_insert_rowid()";
    SqlCommand cmd = new SqlCommand(sql, conn);
    int lastID = (Int32) cmd.ExecuteScalar();

What is a mixin, and why are they useful?

I think of them as a disciplined way of using multiple inheritance - because ultimately a mixin is just another python class that (might) follow the conventions about classes that are called mixins.

My understanding of the conventions that govern something you would call a Mixin are that a Mixin:

  • adds methods but not instance variables (class constants are OK)
  • only inherits from object (in Python)

That way it limits the potential complexity of multiple inheritance, and makes it reasonably easy to track the flow of your program by limiting where you have to look (compared to full multiple inheritance). They are similar to ruby modules.

If I want to add instance variables (with more flexibility than allowed for by single inheritance) then I tend to go for composition.

Having said that, I have seen classes called XYZMixin that do have instance variables.

Switch case in C# - a constant value is expected

Now you can use nameof:

public static void Output<T>(IEnumerable<T> dataSource) where T : class
    string dataSourceName = typeof(T).Name;
    switch (dataSourceName)
        case nameof(CustomerDetails):
            var t = 123;

nameof(CustomerDetails) is basically identical to the string literal "CustomerDetails", but with a compile-time check that it refers to some symbol (to prevent a typo).

nameof appeared in C# 6.0, so after this question was asked.

Explanation of 'String args[]' and static in 'public static void main(String[] args)'

The normal usage of static is to access the function directly with out any object creation. Same as in java main we could not create any object for that class to invoke the main method. It will execute automatically. If we want to execute manually we can call by using main() inside the class and ClassName.main from outside the class.

jQuery $(this) keyword

using $(this) improves performance, as the class/whatever attr u are using to search, need not be searched for multiple times in the entire webpage content.

The model backing the <Database> context has changed since the database was created

I had this issue and it turned out that one project was pointing to SQLExpress but the one with the problem was pointing to LocalDb. (in their respective web.config). Silly oversight but worth noting here in case anyone else is troubleshooting this issue.

How to downgrade to older version of Gradle

got it resolved:

uninstall the entire android studio

uninstalling android with the following commands

rm -Rf /Applications/Android\  
rm -Rf ~/Library/Preferences/AndroidStudio*  
rm -Rf ~/Library/Preferences/*  
rm -Rf ~/Library/Preferences/*  
rm -Rf ~/Library/Application\ Support/AndroidStudio*  
rm -Rf ~/Library/Logs/AndroidStudio*  
rm -Rf ~/Library/Caches/AndroidStudio*  
rm -Rf ~/.AndroidStudio*  
rm -Rf ~/.gradle  
rm -Rf ~/.android  
rm -Rf ~/Library/Android*  
rm -Rf /usr/local/var/lib/android-sdk/  
rm -Rf /Users/<username>/.tooling/gradle

Remove your project and clone it again and then goto Gradle Scripts and open and change the below url which ever version you need


Fastest way to iterate over all the chars in a String

String.toCharArray() creates new char array, means allocation of memory of string length, then copies original char array of string using System.arraycopy() and then returns this copy to caller. String.charAt() returns character at position i from original copy, that's why String.charAt() will be faster than String.toCharArray(). Although, String.toCharArray() returns copy and not char from original String array, where String.charAt() returns character from original char array. Code below returns value at the specified index of this string.

public char charAt(int index) {
    if ((index < 0) || (index >= value.length)) {
        throw new StringIndexOutOfBoundsException(index);
    return value[index];

code below returns a newly allocated character array whose length is the length of this string

public char[] toCharArray() {
    // Cannot use Arrays.copyOf because of class initialization order issues
    char result[] = new char[value.length];
    System.arraycopy(value, 0, result, 0, value.length);
    return result;

Problems with jQuery getJSON using local files in Chrome

This code worked fine with sheet.jsonlocally with browser-sync as the local server. -But when on my remote server I got a 404 for the sheet.json file using Chrome. It worked fine in Safari and Firefox. -Changed the name sheet.json to sheet.JSON. Then it worked on the remote server. Anyone else have this experience?

getthejason = function(){
var dataurl = 'data/sheet.JSON';
var xhr = new XMLHttpRequest();'GET', dataurl, true);
xhr.responseType = 'text';

xhr.onload = function() {

Regex in JavaScript for validating decimal numbers




var regexp = /^\d+(\.\d{1,2})?$/;_x000D_
console.log("'.74' returns " + regexp.test('.74'));_x000D_
console.log("'7' returns " + regexp.test('7'));_x000D_
console.log("'10.5' returns " + regexp.test('10.5'));_x000D_
console.log("'115.25' returns " + regexp.test('115.25'));_x000D_
console.log("'1535.803' returns " + regexp.test('1535.803'));_x000D_
console.log("'153.14.5' returns " + regexp.test('153.14.5'));_x000D_
console.log("'415351108140' returns " + regexp.test('415351108140'));_x000D_
console.log("'415351108140.5' returns " + regexp.test('415351108140.5'));_x000D_
console.log("'415351108140.55' returns " + regexp.test('415351108140.55'));_x000D_
console.log("'415351108140.556' returns " + regexp.test('415351108140.556'));


  1. / / : the beginning and end of the expression
  2. ^ : whatever follows should be at the beginning of the string you're testing
  3. \d+ : there should be at least one digit
  4. ( )? : this part is optional
  5. \. : here goes a dot
  6. \d{1,2} : there should be between one and two digits here
  7. $ : whatever precedes this should be at the end of the string you're testing


You can use or for testing regular expressions directly in the browser!

How should you diagnose the error SEHException - External component has thrown an exception

if you are having a problem as describe in this post: mvc debugger throwing SEHException

then the solution is:

if you have any application from Trusteer (like rapport or anything ) just uninstall and reboot your system, it'll work fine ... found this solution here:

Correct way to pause a Python program

cross-platform way; works everywhere

import os, sys

if sys.platform == 'win32':
    input('Press any key to continue...')

Altering user-defined table types in SQL Server

Here are simple steps that minimize tedium and don't require error-prone semi-automated scripts or pricey tools.

Keep in mind that you can generate DROP/CREATE statements for multiple objects from the Object Explorer Details window (when generated this way, DROP and CREATE scripts are grouped, which makes it easy to insert logic between Drop and Create actions):

Drop and Create To

  1. Back up you database in case anything goes wrong!
  2. Automatically generate the DROP/CREATE statements for all dependencies (or generate for all "Programmability" objects to eliminate the tedium of finding dependencies).
  3. Between the DROP and CREATE [dependencies] statements (after all DROP, before all CREATE), insert generated DROP/CREATE [table type] statements, making the changes you need with CREATE TYPE.
  4. Run the script, which drops all dependencies/UDTTs and then recreates [UDTTs with alterations]/dependencies.

If you have smaller projects where it might make sense to change the infrastructure architecture, consider eliminating user-defined table types. Entity Framework and similar tools allow you to move most, if not all, of your data logic to your code base where it's easier to maintain.

How to change DatePicker dialog color for Android 5.0

Just to mention, you can also use the default a theme like instead.

new DatePickerDialog(MainActivity.this,, new DatePickerDialog.OnDateSetListener() {
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
}, 2015, 02, 26).show();

calling a function from class in python - different way

You need to have an instance of a class to use its methods. Or if you don't need to access any of classes' variables (not static parameters) then you can define the method as static and it can be used even if the class isn't instantiated. Just add @staticmethod decorator to your methods.

class MathsOperations:
    def testAddition (x, y):
        return x + y
    def testMultiplication (a, b):
        return a * b


"Multiple definition", "first defined here" errors

I had a similar issue when not using inline for my global function that was included in two places.

Return empty cell from formula in Excel

If the goal is to be able to display a cell as empty when it in fact has the value zero, then instead of using a formula that results in a blank or empty cell (since there's no empty() function) instead,

  • where you want a blank cell, return a 0 instead of "" and THEN

  • set the number format for the cells like so, where you will have to come up with what you want for positive and negative numbers (the first two items separated by semi-colons). In my case, the numbers I had were 0, 1, 2... and I wanted 0 to show up empty. (I never did figure out what the text parameter was used for, but it seemed to be required).


Django TemplateDoesNotExist?

Works on Django 3

I found I believe good way, I have the base.html in root folder, and all other html files in App folders, I

import os

# This settings are to allow store templates,static and media files in root folder

BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
TEMPLATE_DIR = os.path.join(BASE_DIR,'templates')
STATIC_DIR = os.path.join(BASE_DIR,'static')
MEDIA_DIR = os.path.join(BASE_DIR,'media')

# This is default path from Django, must be added 
#AFTER our BASE_DIR otherwise DB will be broken.
BASE_DIR = Path(__file__).resolve().parent.parent

# add your apps to Installed apps

# Now add TEMPLATE_DIR to  'DIRS' where in TEMPLATES like bellow
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
# On end of put this refferences to Static and Media files
STATIC_URL = '/static/'

MEDIA_URL = '/media/'

If you have problem with Database, please check if you put the original BASE_DIR bellow the new BASE_DIR otherwise change

# Original
'NAME': BASE_DIR / 'db.sqlite3',
# to
'NAME': os.path.join(BASE_DIR,'db.sqlite3'),

Django now will be able to find the HTML and Static files both in the App folders and in Root folder without need of adding the name of App folder in front of the file.

    -static(css,JS ...)
    -templates(base.html, ....)
    -other django files like (, ....)
        -templates(index1.html, other html files can extend now base.html too)
        -other App1 files
        -templates(index2.html, other html files can extend now base.html too)
        -other App2 files

How do I add a project as a dependency of another project?

Assuming the MyEjbProject is not another Maven Project you own or want to build with maven, you could use system dependencies to link to the existing jar file of the project like so


That said it is usually the better (and preferred way) to install the package to the repository either by making it a maven project and building it or installing it the way you already seem to do.

If they are, however, dependent on each other, you can always create a separate parent project (has to be a "pom" project) declaring the two other projects as its "modules". (The child projects would not have to declare the third project as their parent). As a consequence you'd get a new directory for the new parent project, where you'd also quite probably put the two independent projects like this:

|- pom.xml
|- MyEJBProject
|   `- pom.xml
`- MyWarProject
    `- pom.xml

The parent project would get a "modules" section to name all the child modules. The aggregator would then use the dependencies in the child modules to actually find out the order in which the projects are to be built)



That way the projects can relate to each other but (once they are installed in the local repository) still be used independently as artifacts in other projects

Finally, if your projects are not in related directories, you might try to give them as relative modules:

 |- mywarproject
 |   `pom.xml
 |- myejbproject
 |   `pom.xml
 `- parent

now you could just do this (worked in maven 2, just tried it):


How do I push to GitHub under a different username?

If after running git push Git asks for a password of user, but you would like to push as new_user, you may want to use git config remote.origin.url:

$ git push
[email protected]:either/branch/or/path's password:

At this point use ^C to quit git push and use following to push as new_user.

$ git config remote.origin.url
[email protected]:either/branch/or/path

$ git config remote.origin.url [email protected]:either/branch/or/path

$ git push
[email protected]:either/branch/or/path's password:

Use jQuery to get the file input's selected filename without the path

How about something like this?

var pathArray = $('input[type=file]').val().split('\\');
alert(pathArray[pathArray.length - 1]);

Is it possible to disable the network in iOS Simulator?

If you have at least 2 wifi networks to connect is a very simple way is to use a bug in iOS simulator:

  1. quit from simulator (cmd-q) if it is open
  2. connect your Mac to one wifi (it may be not connected to internet, no matters)
  3. launch simulator (menu: xCode->Open Developer Tool->iOs Simulator) and wait while it is loaded
  4. switch wifi network to other one
  5. profit

The bug is that simulator tries to use a network (IP?) which is not connected already.

Until you relaunched simulator- it will have no internet (even if that first wifi network you connected had internet connection), so you can run (cmd-R) and stop (cmd-.) project(s) to use simulator without connection, but your Mac will be connected.

Then, if you'll need to run simulator connected- just quit and launch it.

how to install apk application from my pc to my mobile android

1) Put the apk on your SDKCard and install file browsers like "Estrongs File Explorer", "Easy Installer", etc...

2) Go to your mobile settings - applications- debuging - and thick "USB debugging" enter image description here

How to detect Adblock on my website?

My advice is: don't do it!

Any scenario where you treat people as "wrongdoers" is going to result in them fighting back.

Here's my proposal.

Put a small unobtrusive message at the top of the page (regardless of whether ads are being blocked) with the text I *totally* respect your right to block ads and a link to another page/pop-up entitled Read more ....

On the other page, make it clear that you understand it's their computer and they are free to use ad blocking.

Also make it clear in a non-accusatory way that the use of these blockers makes it more difficult for you to deliver great content (explaining why in detail) and that, while you'd prefer the ad blocking to not happen on your site, it's totally their decision. Focus on the positives of turning off blocking.

Those who are vehemently opposed to ads will ignore this but you never stood a chance of convincing them anyway. Those who are indifferent may well be swayed by your appeal since you're not doing the whole "let me get my way or I'll take my ball and go home" thing that honestly should be the exclusive domain of five year old children.

Remember, no-one held a gun to your head and forced you to put your stuff on the net. Treat your readership/users with respect and you'll probably find a good number of them will reciprocate.

In a Bash script, how can I exit the entire script if a certain condition occurs?

If you will invoke the script with source, you can use return <x> where <x> will be the script exit status (use a non-zero value for error or false). But if you invoke an executable script (i.e., directly with its filename), the return statement will result in a complain (error message "return: can only `return' from a function or sourced script").

If exit <x> is used instead, when the script is invoked with source, it will result in exiting the shell that started the script, but an executable script will just terminate, as expected.

To handle either case in the same script, you can use

return <x> 2> /dev/null || exit <x>

This will handle whichever invocation may be suitable. That is assuming you will use this statement at the script's top level. I would advise against directly exiting the script from within a function.

Note: <x> is supposed to be just a number.

Cmake is not able to find Python-libraries

Some last version of Ubuntu installs Python 3.4 by default and the CMake version from Ubuntu (2.8) only searches up to Python 3.3.

Try to add set(Python_ADDITIONAL_VERSIONS 3.4) before the find_package statement.

Remember to clean CMakeCache.txt too.

Android Recyclerview GridLayoutManager column spacing

The answers on for this question seem more complex than they should be. Here's my take on this.

Let's say you want 1dp spacing between grid items. Do the following:

  1. Add a padding of 0.5dp to each item
  2. Add a padding of -0.5dp to the RecycleView
  3. That's it! :)

"Unorderable types: int() < str()"

Just a side note, in Python 2.0 you could compare anything to anything (int to string). As this wasn't explicit, it was changed in 3.0, which is a good thing as you are not running into the trouble of comparing senseless values with each other or when you forget to convert a type.

Swift double to string

I would prefer NSNumber and NumberFormatter approach (where need), also u can use extension to avoid bloating code

extension Double {

   var toString: String {
      return NSNumber(value: self).stringValue


U can also need reverse approach

extension String {

    var toDouble: Double {
        return Double(self) ?? .nan


Regular expression for 10 digit number without any special characters

An example of how to implement it:

public bool ValidateSocialSecNumber(string socialSecNumber)
    //Accepts only 10 digits, no more no less. (Like Mike's answer)
    Regex pattern = new Regex(@"(?<!\d)\d{10}(?!\d)");

        //Do something
        return true;
        return false;

You could've also done it in another way by e.g. using Match and then wrapping a try-catch block around the pattern matching. However, if a wrong input is given quite often, it's quite expensive to throw an exception. Thus, I prefer the above way, in simple cases at least.

How to create a popup window (PopupWindow) in Android

I construct my own class, and then call it from my activity, overriding small methods like showAtLocation. I've found its easier when I have 4 to 5 popups in my activity to do this.

public class ToggleValues implements OnClickListener{

    private View pView;
    private LayoutInflater inflater;
    private PopupWindow pop;
    private Button one, two, three, four, five, six, seven, eight, nine, blank;
    private ImageButton eraser;
    private int selected = 1;
    private Animation appear;

    public ToggleValues(int id, Context c, int screenHeight){
        inflater = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        pop = new PopupWindow(inflater.inflate(id, null, false), 265, (int)(screenHeight * 0.45), true);
        pView = pop.getContentView();

        appear = AnimationUtils.loadAnimation(c, R.anim.appear);

        one = (Button) pView.findViewById(;
        two = (Button) pView.findViewById(;
        three = (Button) pView.findViewById(;
        four = (Button) pView.findViewById(;
        five = (Button) pView.findViewById(;
        six = (Button) pView.findViewById(;
        seven = (Button) pView.findViewById(;
        eight = (Button) pView.findViewById(;
        nine = (Button) pView.findViewById(;
        blank = (Button) pView.findViewById(;
        eraser = (ImageButton) pView.findViewById(;

    public void showAtLocation(View v) {
        pop.showAtLocation(v, Gravity.BOTTOM | Gravity.LEFT, 40, 40);

    public void dismiss(){ 

    public boolean isShowing() {
            return true;
            return false;

    public int getSelected(){
        return selected;

    public void onClick(View arg0) {
        if(arg0 == one){
        }else if(arg0 == two){
        }else if(arg0 == three){
        }else if(arg0 == four){
        }else if(arg0 == five){
        }else if(arg0 == six){
        }else if(arg0 == seven){
        }else if(arg0 == eight){
        }else if(arg0 == nine){
        }else if(arg0 == blank){
        }else if(arg0 == eraser){


Save PHP array to MySQL?

check out the implode function, since the values are in an array, you want to put the values of the array into a mysql query that inserts the values into a table.

$query = "INSERT INto hardware (specifications) VALUES (".implode(",",$specifications).")";

If the values in the array are text values, you will need to add quotes

$query = "INSERT INto hardware (specifications) VALUES ("'.implode("','",$specifications)."')";


Also, if you don't want duplicate values, switch the "INto" to "IGNORE" and only unique values will be inserted into the table.

Add/Delete table rows dynamically using JavaScript

Easy Javascript Add more Rows with delete functionality

Cheers !

<TABLE id="dataTable">
               <INPUT TYPE=submit name=submit id=button class=btn_medium VALUE=\'Save\'  >
               <INPUT type="button" value="AddMore" onclick="addRow(\'dataTable\')" class="btn_medium"    /> 

                <input type="text" size="20" name="values[]"/> <br><small><font color="gray">Enter Title</font></small> 


function addRow(tableID) {

        var table = document.getElementById(tableID);

        var rowCount = table.rows.length;
        var row = table.insertRow(rowCount);

        var cell3 = row.insertCell(0);
       cell3.innerHTML = cell3.innerHTML +' <input type="text" size="20" name="values[]"/> <INPUT type="button"  class="btn_medium" value="Remove" onclick="this.parentNode.parentNode.parentNode.removeChild(this.parentNode.parentNode);" /><br><small><font color="gray">Enter Title</font></small>';
  //cell3.innerHTML = cell3.innerHTML +' <input type="text" size="20" name="values[]"/> <INPUT type="button"  class="btn_medium" value="Remove" onclick="this.parentNode.parentNode.innerHTML=\'\';" /><br><small><font color="gray">Enter Title</font></small>';       


What is the proper way to comment functions in Python?

The principles of good commenting are fairly subjective, but here are some guidelines:

  • Function comments should describe the intent of a function, not the implementation
  • Outline any assumptions that your function makes with regards to system state. If it uses any global variables (tsk, tsk), list those.
  • Watch out for excessive ASCII art. Having long strings of hashes may seem to make the comments easier to read, but they can be annoying to deal with when comments change
  • Take advantage of language features that provide 'auto documentation', i.e., docstrings in Python, POD in Perl, and Javadoc in Java

How to insert a data table into SQL Server database table?

I am giving a very simple code, which i used in my solution (I have the same problem statement as yours)

    SqlConnection con = connection string ;
//new SqlConnection("Data Source=.;uid=sa;pwd=sa123;database=Example1");
string sql = "Create Table abcd (";
foreach (DataColumn column in dt.Columns)
    sql += "[" + column.ColumnName + "] " + "nvarchar(50)" + ",";
sql = sql.TrimEnd(new char[] { ',' }) + ")";
SqlCommand cmd = new SqlCommand(sql, con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
using (var adapter = new SqlDataAdapter("SELECT * FROM abcd", con)) 
using(var builder = new SqlCommandBuilder(adapter))
adapter.InsertCommand = builder.GetInsertCommand();
// adapter.Update(ds.Tables[0]); (Incase u have a data-set)

I have given a predefined table-name as "abcd" (you must take care that a table by this name doesn't exist in your database). Please vote my answer if it works for you!!!! :)

How to create an array containing 1...N

I would do it this way using ...Array(N).keys()

var foo = [...Array(5).keys()].map(foo => foo + 1)


Android custom Row Item for ListView

you can follow BaseAdapter and create your custome Xml file and bind it with you BaseAdpter and populate it with Listview see here need to change xml file as Require.

Convert Unicode data to int in python

In python, integers and strings are immutable and are passed by value. You cannot pass a string, or integer, to a function and expect the argument to be modified.

So to convert string limit="100" to a number, you need to do

limit = int(limit) # will return new object (integer) and assign to "limit"

If you really want to go around it, you can use a list. Lists are mutable in python; when you pass a list, you pass it's reference, not copy. So you could do:

def int_in_place(mutable):
    mutable[0] = int(mutable[0])

mutable = ["1000"]
# now mutable is a list with a single integer

But you should not need it really. (maybe sometimes when you work with recursions and need to pass some mutable state).

Select info from table where row has max date

SELECT group,MAX(date) as max_date
FROM table
WHERE checks>0
GROUP BY group

That works to get the max date..join it back to your data to get the other columns:

Select group,max_date,checks
from table t
inner join 
(SELECT group,MAX(date) as max_date
FROM table
WHERE checks>0
GROUP BY group)a
on = and a.max_date = date

Inner join functions as the filter to get the max record only.

FYI, your column names are horrid, don't use reserved words for columns (group, date, table).

Adding a directory to the PATH environment variable in Windows

You don't need any set or setx command. Simply open the terminal and type:


This shows the current value of PATH variable. Now you want to add directory to it? Simply type:

PATH %PATH%;C:\xampp\php

If for any reason you want to clear the PATH variable (no paths at all or delete all paths in it), type:



Like Danial Wilson noted in comment below, it sets the path only in the current session. To set the path permanently, use setx but be aware, although that sets the path permanently, but not in the current session, so you have to start a new command line to see the changes. More information is here.

To check if an environmental variable exist or see its value, use the ECHO command:


Spring Boot - Handle to Hibernate SessionFactory

SessionFactory sessionFactory = entityManagerFactory.unwrap(SessionFactory.class);

where entityManagerFactory is an JPA EntityManagerFactory.

Find files and tar them (with spaces)

If you have multiple files or directories and you want to zip them into independent *.gz file you can do this. Optional -type f -atime

find -name "httpd-log*.txt" -type f -mtime +1 -exec tar -vzcf {}.gz {} \;

This will compress




Create line after text with css

There's no need for extra wrappers or span elements anymore. Flexbox and Grid can handle this easily.

h2 {_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
h2::after {_x000D_
  content: '';_x000D_
  flex: 1;_x000D_
  margin-left: 1rem;_x000D_
  height: 1px;_x000D_
  background-color: #000;_x000D_

How to get the insert ID in JDBC?

You can use following java code to get new inserted id.

ps = con.prepareStatement(query, Statement.RETURN_GENERATED_KEYS);
ps.setInt(1, quizid);
ps.setInt(2, userid);

ResultSet rs = ps.getGeneratedKeys();
if ( {
    lastInsertId = rs.getInt(1);

How to recover Git objects damaged by hard disk failure?

Try the following commands at first (re-run again if needed):

$ git fsck --full
$ git gc
$ git gc --prune=today
$ git fetch --all
$ git pull --rebase

And then you you still have the problems, try can:

  • remove all the corrupt objects, e.g.

    fatal: loose object 91c5...51e5 (stored in .git/objects/06/91c5...51e5) is corrupt
    $ rm -v .git/objects/06/91c5...51e5
  • remove all the empty objects, e.g.

    error: object file .git/objects/06/91c5...51e5 is empty
    $ find .git/objects/ -size 0 -exec rm -vf "{}" \;
  • check a "broken link" message by:

    git ls-tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8

    This will tells you what file the corrupt blob came from!

  • to recover file, you might be really lucky, and it may be the version that you already have checked out in your working tree:

    git hash-object -w my-magic-file

    again, and if it outputs the missing SHA1 (4b945..) you're now all done!

  • assuming that it was some older version that was broken, the easiest way to do it is to do:

    git log --raw --all --full-history -- subdirectory/my-magic-file

    and that will show you the whole log for that file (please realize that the tree you had may not be the top-level tree, so you need to figure out which subdirectory it was in on your own), then you can now recreate the missing object with hash-object again.

  • to get a list of all refs with missing commits, trees or blobs:

    $ git for-each-ref --format='%(refname)' | while read ref; do git rev-list --objects $ref >/dev/null || echo "in $ref"; done

    It may not be possible to remove some of those refs using the regular branch -d or tag -d commands, since they will die if git notices the corruption. So use the plumbing command git update-ref -d $ref instead. Note that in case of local branches, this command may leave stale branch configuration behind in .git/config. It can be deleted manually (look for the [branch "$ref"] section).

  • After all refs are clean, there may still be broken commits in the reflog. You can clear all reflogs using git reflog expire --expire=now --all. If you do not want to lose all of your reflogs, you can search the individual refs for broken reflogs:

    $ (echo HEAD; git for-each-ref --format='%(refname)') | while read ref; do git rev-list -g --objects $ref >/dev/null || echo "in $ref"; done

    (Note the added -g option to git rev-list.) Then, use git reflog expire --expire=now $ref on each of those. When all broken refs and reflogs are gone, run git fsck --full in order to check that the repository is clean. Dangling objects are Ok.

Below you can find advanced usage of commands which potentially can cause lost of your data in your git repository if not used wisely, so make a backup before you accidentally do further damages to your git. Try on your own risk if you know what you're doing.

To pull the current branch on top of the upstream branch after fetching:

$ git pull --rebase

You also may try to checkout new branch and delete the old one:

$ git checkout -b new_master origin/master

To find the corrupted object in git for removal, try the following command:

while [ true ]; do f=`git fsck --full 2>&1|awk '{print $3}'|sed -r 's/(^..)(.*)/objects\/\1\/\2/'`; if [ ! -f "$f" ]; then break; fi; echo delete $f; rm -f "$f"; done

For OSX, use sed -E instead of sed -r.

Other idea is to unpack all objects from pack files to regenerate all objects inside .git/objects, so try to run the following commands within your repository:

$ cp -fr .git/objects/pack .git/objects/pack.bak
$ for i in .git/objects/pack.bak/*.pack; do git unpack-objects -r < $i; done
$ rm -frv .git/objects/pack.bak

If above doesn't help, you may try to rsync or copy the git objects from another repo, e.g.

$ rsync -varu git_server:/path/to/git/.git local_git_repo/
$ rsync -varu /local/path/to/other-working/git/.git local_git_repo/
$ cp -frv ../other_repo/.git/objects .git/objects

To fix the broken branch when trying to checkout as follows:

$ git checkout -f master
fatal: unable to read tree 5ace24d474a9535ddd5e6a6c6a1ef480aecf2625

Try to remove it and checkout from upstream again:

$ git branch -D master
$ git checkout -b master github/master

In case if git get you into detached state, checkout the master and merge into it the detached branch.

Another idea is to rebase the existing master recursively:

$ git reset HEAD --hard
$ git rebase -s recursive -X theirs origin/master

See also:

Why doesn't Git ignore my specified file?

What I did it to ignore the settings.php file successfully:

  1. git rm --cached sites/default/settings.php
  2. commit (up to here didn't work)
  3. manually deleted sites/default/settings.php (this did the trick)
  4. git add .
  5. commit (ignored successfully)

I think if there's the committed file on Git then ignore doesn't work as expected. Just delete the file and commit. Afterwards it'll ignore.

Correct way to remove plugin from Eclipse

Correct way to remove install plug-in from Eclipse/STS :

Go to install folder of eclipse ----> plugin --> select required plugin and remove it.


Step 1. 

Step 2. 
select and remove related plugins jars.

calling server side event from html button control

The easiest way to accomplish this is to override the RaisePostBackEvent method.

<input type="button" ID="btnRaisePostBack" runat="server" onclick="raisePostBack();" ... />

And in your JavaScript:

raisePostBack = function(){
    __doPostBack("<%=btnRaisePostBack.ClientID%>", "");

And in your code:

protected override void RaisePostBackEvent(IPostBackEventHandler source, string eventArgument)
    //call the RaisePostBack event 
    base.RaisePostBackEvent(source, eventArgument);

    if (source == btnRaisePostBack)
         //do some logic

How can I jump to class/method definition in Atom text editor?

Use atom-ctags as a package for C language with all things you need:

  • Generated ctags for your project. Auto-complete.
  • Go to declaration: Ctrl+Alt+Down and Alt+Click by default.
  • There are customizable options for Click action.

ng-model for `<input type="file"/>` (with directive DEMO)

How to enable <input type="file"> to work with ng-model

Working Demo of Directive that Works with ng-model

The core ng-model directive does not work with <input type="file"> out of the box.

This custom directive enables ng-model and has the added benefit of enabling the ng-change, ng-required, and ng-form directives to work with <input type="file">.


angular.module("app").directive("selectNgFiles", function() {
  return {
    require: "ngModel",
    link: function postLink(scope,elem,attrs,ngModel) {
      elem.on("change", function(e) {
        var files = elem[0].files;
<script src="//"></script>
  <body ng-app="app">
    <h1>AngularJS Input `type=file` Demo</h1>
    <input type="file" select-ng-files ng-model="fileArray" multiple>

    <code><table ng-show="fileArray.length">
    <tr ng-repeat="file in fileArray">
      <td>{{file.lastModified | date  : 'MMMdd,yyyy'}}</td>

declaring a priority_queue in c++ with a custom comparator

Answering your question directly:

I'm trying to declare a priority_queue of nodes, using bool Compare(Node a, Node b) as the comparator function

What I currently have is:

priority_queue<Node, vector<Node>, Compare> openSet;

For some reason, I'm getting Error:

"Compare" is not a type name

The compiler is telling you exactly what's wrong: Compare is not a type name, but an instance of a function that takes two Nodes and returns a bool.
What you need is to specify the function pointer type:
std::priority_queue<Node, std::vector<Node>, bool (*)(Node, Node)> openSet(Compare)

Conversion from Long to Double in Java

As already mentioned, you can simply cast long to double. But be careful with long to double conversion because long to double is a narrowing conversion in java.

Conversion from type double to type long requires a nontrivial translation from a 64-bit floating-point value to the 64-bit integer representation. Depending on the actual run-time value, information may be lost.

e.g. following program will print 1 not 0

    long number = 499999999000000001L;
    double converted = (double) number;
    System.out.println( number - (long) converted);

bower automatically update bower.json

from bower help, save option has a capital S

-S, --save  Save installed packages into the project's bower.json dependencies

file_get_contents behind a proxy?

Depending on how the proxy login works stream_context_set_default might help you.

$context  = stream_context_set_default(
      'header'=>'Authorization: Basic ' . base64_encode('username'.':'.'userpass')
$result = file_get_contents('http://..../...');

Plotting two variables as lines using ggplot2 on the same graph

The general approach is to convert the data to long format (using melt() from package reshape or reshape2) or gather()/pivot_longer() from the tidyr package:


test_data_long <- melt(test_data, id="date")  # convert to long format

       aes(x=date, y=value, colour=variable)) +

ggplot2 output

Also see this question on reshaping data from wide to long.

What’s the difference between “{}” and “[]” while declaring a JavaScript array?

It can be understood like this:

var a= []; //creates a new empty array
var a= {}; //creates a new empty object

You can also understand that

var a = {}; is equivalent to var a= new Object();


You can use Arrays when you are bothered about the order of elements(of same type) in your collection else you can use objects. In objects the order is not guaranteed.

How to store printStackTrace into a string

You can use the ExceptionUtils.getStackTrace(Throwable t); from Apache Commons 3 class org.apache.commons.lang3.exception.ExceptionUtils.

ExceptionUtils.getStackTrace(Throwable t)

Code example:

try {

  // your code here

} catch(Exception e) {
  String s = ExceptionUtils.getStackTrace(e);

Difference between CR LF, LF and CR line break types?

The sad state of "record separators" or "line terminators" is a legacy of the dark ages of computing.

Now, we take it for granted that anything we want to represent is in some way structured data and conforms to various abstractions that define lines, files, protocols, messages, markup, whatever.

But once upon a time this wasn't exactly true. Applications built-in control characters and device-specific processing. The brain-dead systems that required both CR and LF simply had no abstraction for record separators or line terminators. The CR was necessary in order to get the teletype or video display to return to column one and the LF (today, NL, same code) was necessary to get it to advance to the next line. I guess the idea of doing something other than dumping the raw data to the device was too complex.

Unix and Mac actually specified an abstraction for the line end, imagine that. Sadly, they specified different ones. (Unix, ahem, came first.) And naturally, they used a control code that was already "close" to S.O.P.

Since almost all of our operating software today is a descendent of Unix, Mac, or MS operating SW, we are stuck with the line ending confusion.

process.waitFor() never returns

I think I observed a similar problem: some processes started, seemed to run successfully but never completed. The function waitFor() was waiting forever except if I killed the process in Task Manager.
However, everything worked well in cases the length of the command line was 127 characters or shorter. If long file names are inevitable you may want to use environmental variables, which may allow you keeping the command line string short. You can generate a batch file (using FileWriter) in which you set your environmental variables before calling the program you actually want to run. The content of such a batch could look like:

    set INPUTFILE="C:\Directory 0\Subdirectory 1\AnyFileName"
    set OUTPUTFILE="C:\Directory 2\Subdirectory 3\AnotherFileName"
    set MYPROG="C:\Directory 4\Subdirectory 5\ExecutableFileName.exe"

Last step is running this batch file using Runtime.

What's the difference between .bashrc, .bash_profile, and .environment?

That's simple. It's explained in man bash:

       The bash executable
       The systemwide initialization file, executed for login shells
       The personal initialization file, executed for login shells
       The individual per-interactive-shell startup file
       The individual login shell cleanup file, executed when a login shell exits
       Individual readline initialization file

Login shells are the ones that are read one you login (so, they are not executed when merely starting up xterm, for example). There are other ways to login. For example using an X display manager. Those have other ways to read and export environment variables at login time.

Also read the INVOCATION chapter in the manual. It says "The following paragraphs describe how bash executes its startup files.", i think that's a spot-on :) It explains what an "interactive" shell is too.

Bash does not know about .environment. I suspect that's a file of your distribution, to set environment variables independent of the shell that you drive.

Angularjs: Get element in controller

$element is one of four locals that $compileProvider gives to $controllerProvider which then gets given to $injector. The injector injects locals in your controller function only if asked.

The four locals are:

  • $scope
  • $element
  • $attrs
  • $transclude

The official documentation: AngularJS $compile Service API Reference - controller

The source code from Github angular.js/compile.js:

 function setupControllers($element, attrs, transcludeFn, controllerDirectives, isolateScope, scope) {
    var elementControllers = createMap();
    for (var controllerKey in controllerDirectives) {
      var directive = controllerDirectives[controllerKey];
      var locals = {
        $scope: directive === newIsolateScopeDirective || directive.$$isolateScope ? isolateScope : scope,
        $element: $element,
        $attrs: attrs,
        $transclude: transcludeFn

      var controller = directive.controller;
      if (controller == '@') {
        controller = attrs[];

      var controllerInstance = $controller(controller, locals, true, directive.controllerAs);

How can I create numbered map markers in Google Maps V3?

Based on @dave1010 answer but with updated https links.

Numbered marker:|FF0000|000000

Text marker:|0|FF0000|12|_|Marker

Insert multiple values using INSERT INTO (SQL Server 2005)

The syntax you are using is new to SQL Server 2008:

INSERT INTO [MyDB].[dbo].[MyTable]

For SQL Server 2005, you will have to use multiple INSERT statements:

INSERT INTO [MyDB].[dbo].[MyTable]

INSERT INTO [MyDB].[dbo].[MyTable]

One other option is to use UNION ALL:

INSERT INTO [MyDB].[dbo].[MyTable]
SELECT 1000, N'test' UNION ALL
SELECT 1001, N'test2'

Creating a select box with a search option

Use a data list instead.

<form action="/action_page.php" method="get">
      <input list="browsers" name="browser">
      <datalist id="browsers">
        <option value="Internet Explorer">
        <option value="Firefox">
        <option value="Chrome">
        <option value="Opera">
        <option value="Safari">
      <input type="submit">

Not supported I.E. 9 and back.

regex to match a single character that is anything but a space

The following should suffice:

[^ ]

If you want to expand that to anything but white-space (line breaks, tabs, spaces, hard spaces):



\S  # Note this is a CAPITAL 'S'!

How to find the lowest common ancestor of two nodes in any binary tree?

You are correct that without a parent node, solution with traversal will give you O(n) time complexity.

Traversal approach Suppose you are finding LCA for node A and B, the most straightforward approach is to first get the path from root to A and then get the path from root to B. Once you have these two paths, you can easily iterate over them and find the last common node, which is the lowest common ancestor of A and B.

Recursive solution Another approach is to use recursion. First, we can get LCA from both left tree and right tree (if exists). If the either of A or B is the root node, then the root is the LCA and we just return the root, which is the end point of the recursion. As we keep divide the tree into sub-trees, eventually, we’ll hit either A and B.

To combine sub-problem solutions, if LCA(left tree) returns a node, we know that both A and B locate in left tree and the returned node is the final result. If both LCA(left) and LCA(right) return non-empty nodes, it means A and B are in left and right tree respectively. In this case, the root node is the lowest common node.

Check Lowest Common Ancestor for detailed analysis and solution.

c++ boost split string

My best guess at why you had problems with the ----- covering your first result is that you actually read the input line from a file. That line probably had a \r on the end so you ended up with something like this:


What happened is the machine actually printed this:


That means, because of the carriage return at the end of test3, that the dashes after test3 were printed over the top of the first word (and a few of the existing dashes between test and test2 but you wouldn't notice that because they were already dashes).

How to access cookies in AngularJS?

The original accepted answer mentions jquery.cookie plugin. A few months ago though, it was renamed to js-cookie and the jQuery dependency removed. One of the reasons was just to make it easy to integrate with other frameworks, like Angular.

Now, if you want to integrate js-cookie with angular, it is as easy as something like:

module.factory( "cookies", function() {
  return Cookies.noConflict();

And that's it. No jQuery. No ngCookies.

You can also create custom instances to handle specific server-side cookies that are written differently. Take for example PHP, that convert the spaces in the server-side to a plus sign + instead of also percent-encode it:

module.factory( "phpCookies", function() {
  return Cookies
    .withConverter(function( value, name ) {
      return value
            // Decode all characters according to the "encodeURIComponent" spec
            .replace(/(%[0-9A-Z]{2})+/g, decodeURIComponent)
            // Decode the plus sign to spaces
            .replace(/\+/g, ' ')

The usage for a custom Provider would be something like this:

module.service( "customDataStore", [ "phpCookies", function( phpCookies ) {
  this.storeData = function( data ) {
    phpCookies.set( "data", data );
  this.containsStoredData = function() {
    return phpCookies.get( "data" );

I hope this helps anyone.

See detailed info in this issue:

For detailed docs on how to integrate with server-side, see here:

CUDA incompatible with my gcc version

gcc 4.5 and 4.6 are not supported with CUDA - code won't compile and the rest of the toolchain, including cuda-gdb, won't work properly. You cannot use them, and the restriction is non-negotiable.

Your only solution is to install a gcc 4.4 version as a second compiler (most distributions will allow that). There is an option to nvcc --compiler-bindir which can be used to point to an alternative compiler. Create a local directory and then make symbolic links to the supported gcc version executables. Pass that local directory to nvcc via the --compiler-bindir option, and you should be able to compile CUDA code without affecting the rest of your system.


Note that this question, and answer, pertain to CUDA 4.

Since it was written, NVIDIA has continued to expand support for later gcc versions in newer CUDA toolchain release

  • As of the CUDA 4.1 release, gcc 4.5 is now supported. gcc 4.6 and 4.7 are unsupported.
  • As of the CUDA 5.0 release, gcc 4.6 is now supported. gcc 4.7 is unsupported.
  • As of the CUDA 6.0 release, gcc 4.7 is now supported.
  • As of the CUDA 7.0 release, gcc 4.8 is fully supported, with 4.9 support on Ubuntu 14.04 and Fedora 21.
  • As of the CUDA 7.5 release, gcc 4.8 is fully supported, with 4.9 support on Ubuntu 14.04 and Fedora 21.
  • As of the CUDA 8 release, gcc 5.3 is fully supported on Ubuntu 16.06 and Fedora 23.
  • As of the CUDA 9 release, gcc 6 is fully supported on Ubuntu 16.04, Ubuntu 17.04 and Fedora 25.
  • The CUDA 9.2 release adds support for gcc 7
  • The CUDA 10.1 release adds support for gcc 8
  • The CUDA 10.2 release continues support for gcc 8
  • The CUDA 11.0 release adds support for gcc 9 on Ubuntu 20.04
  • The CUDA 11.1 release expands gcc 9 support across most distributions and adds support for gcc 10 on Fedora linux

There is presently (as of CUDA 11.1) no gcc 10 support in CUDA other than Fedora linux

Note that NVIDIA has recently added a very useful table here which contains the supported compiler and OS matrix for the current CUDA release.

When is std::weak_ptr useful?

I see std::weak_ptr<T> as a handle to a std::shared_ptr<T>: It allows me to get the std::shared_ptr<T> if it still exists, but it will not extend its lifetime. There are several scenarios when such point of view is useful:

// Some sort of image; very expensive to create.
std::shared_ptr< Texture > texture;

// A Widget should be able to quickly get a handle to a Texture. On the
// other hand, I don't want to keep Textures around just because a widget
// may need it.

struct Widget {
    std::weak_ptr< Texture > texture_handle;
    void render() {
        if (auto texture = texture_handle.get(); texture) {
            // do stuff with texture. Warning: `texture`
            // is now extending the lifetime because it
            // is a std::shared_ptr< Texture >.
        } else {
            // gracefully degrade; there's no texture.

Another important scenario is to break cycles in data structures.

// Asking for trouble because a node owns the next node, and the next node owns
// the previous node: memory leak; no destructors automatically called.
struct Node {
    std::shared_ptr< Node > next;
    std::shared_ptr< Node > prev;

// Asking for trouble because a parent owns its children and children own their
// parents: memory leak; no destructors automatically called.
struct Node {
    std::shared_ptr< Node > parent;
    std::shared_ptr< Node > left_child;
    std::shared_ptr< Node > right_child;

// Better: break dependencies using a std::weak_ptr (but not best way to do it;
// see Herb Sutter's talk).
struct Node {
    std::shared_ptr< Node > next;
    std::weak_ptr< Node > prev;

// Better: break dependencies using a std::weak_ptr (but not best way to do it;
// see Herb Sutter's talk).
struct Node {
    std::weak_ptr< Node > parent;
    std::shared_ptr< Node > left_child;
    std::shared_ptr< Node > right_child;

Herb Sutter has an excellent talk that explains the best use of language features (in this case smart pointers) to ensure Leak Freedom by Default (meaning: everything clicks in place by construction; you can hardly screw it up). It is a must watch.

Using global variables in a function

Python uses a simple heuristic to decide which scope it should load a variable from, between local and global. If a variable name appears on the left hand side of an assignment, but is not declared global, it is assumed to be local. If it does not appear on the left hand side of an assignment, it is assumed to be global.

>>> import dis
>>> def foo():
...     global bar
...     baz = 5
...     print bar
...     print baz
...     print quux
>>> dis.disassemble(foo.func_code)
  3           0 LOAD_CONST               1 (5)
              3 STORE_FAST               0 (baz)

  4           6 LOAD_GLOBAL              0 (bar)
              9 PRINT_ITEM          
             10 PRINT_NEWLINE       

  5          11 LOAD_FAST                0 (baz)
             14 PRINT_ITEM          
             15 PRINT_NEWLINE       

  6          16 LOAD_GLOBAL              1 (quux)
             19 PRINT_ITEM          
             20 PRINT_NEWLINE       
             21 LOAD_CONST               0 (None)
             24 RETURN_VALUE        

See how baz, which appears on the left side of an assignment in foo(), is the only LOAD_FAST variable.

How to toggle (hide / show) sidebar div using jQuery

See this fiddle for a preview and check the documentation for jquerys toggle and animate methods.


Basically you animate on the properties that sets the layout.

A more advanced version:


This stops the previous animation, clears animation queue and begins the new animation.

SQLAlchemy: What's the difference between flush() and commit()?

Use flush when you need to write, for example to get a primary key ID from an autoincrementing counter.

john=Person(name='John Smith', parent=None)

son=Person(name='Bill Smith',

Without flushing, john would never get an ID from the DB and so couldn't represent the parent/child relationship in code.

Like others have said, without commit() none of this will be permanently persisted to DB.

How to change the DataTable Column Name?

Rename the Column by doing the following:

dataTable.Columns["ColumnName"].ColumnName = "newColumnName";

In C - check if a char exists in a char array

You want

strchr (const char *s, int c)

If the character c is in the string s it returns a pointer to the location in s. Otherwise it returns NULL. So just use your list of invalid characters as the string.

invalid use of non-static member function

The simplest fix is to make the comparator function be static:

static int comparator (const Bar & first, const Bar & second);

When invoking it in Count, its name will be Foo::comparator.

The way you have it now, it does not make sense to be a non-static member function because it does not use any member variables of Foo.

Another option is to make it a non-member function, especially if it makes sense that this comparator might be used by other code besides just Foo.

Best practices to test protected methods with PHPUnit

I think troelskn is close. I would do this instead:

class ClassToTest
   protected function testThisMethod()
     // Implement stuff here

Then, implement something like this:

class TestClassToTest extends ClassToTest
  public function testThisMethod()
    return parent::testThisMethod();

You then run your tests against TestClassToTest.

It should be possible to automatically generate such extension classes by parsing the code. I wouldn't be surprised if PHPUnit already offers such a mechanism (though I haven't checked).

How to create <input type=“text”/> dynamically

With JavaScript:

var input = document.createElement("input");
input.type = "text";
input.className = "css-class-name"; // set the CSS class
container.appendChild(input); // put it into the DOM

git add remote branch

I am not sure if you are trying to create a remote branch from a local branch or vice versa, so I've outlined both scenarios as well as provided information on merging the remote and local branches.

Creating a remote called "github":

git remote add github git://
git fetch github

List all remote branches:

git branch -r

Create a new local branch (test) from a github's remote branch (pu):

git branch test github/pu
git checkout test

Merge changes from github's remote branch (pu) with local branch (test):

git fetch github
git checkout test
git merge github/pu

Update github's remote branch (pu) from a local branch (test):

git push github test:pu

Creating a new branch on a remote uses the same syntax as updating a remote branch. For example, create new remote branch (beta) on github from local branch (test):

git push github test:beta

Delete remote branch (pu) from github:

git push github :pu

Why are primes important in cryptography?

Because factorization algorithms speed up considerably with each factor found. Making both private keys prime ensures the first factor found will also be the last. Ideally, both private keys will also be nearly equal in value since only the strength of the weaker key matters.

How to get URL of current page in PHP

The other answers are correct. However, a quick note: if you're looking to grab the stuff after the ? in a URI, you should use the $_GET[] array.

Change URL without refresh the page


Based on Manipulating the browser history, passing the empty string as second parameter of pushState method (aka title) should be safe against future changes to the method, so it's better to use pushState like this:

history.pushState(null, '', '/en/step2');    

You can read more about that in mentioned article

Original Answer

Use history.pushState like this:

history.pushState(null, null, '/en/step2');

Update 2 to answer Idan Dagan's comment:

Why not using history.replaceState()?

From MDN

history.replaceState() operates exactly like history.pushState() except that replaceState() modifies the current history entry instead of creating a new one

That means if you use replaceState, yes the url will be changed but user can not use Browser's Back button to back to prev. state(s) anymore (because replaceState doesn't add new entry to history) and it's not recommended and provide bad UX.

Update 3 to add window.onpopstate

So, as this answer got your attention, here is additional info about manipulating the browser history, after using pushState, you can detect the back/forward button navigation by using window.onpopstate like this:

window.onpopstate = function(e) {
    // ... 

As the first argument of pushState is an object, if you passed an object instead of null, you can access that object in onpopstate which is very handy, here is how:

window.onpopstate = function(e) {
    if(e.state) {

Update 4 to add Reading the current state:

When your page loads, it might have a non-null state object, you can read the state of the current history entry without waiting for a popstate event using the history.state property like this:


Bonus: Use following to check history.pushState support:

if (history.pushState) {
  // \o/

How to strip HTML tags from a string in SQL Server?

Try this if you don't want to use the UDF function.

SELECT COLUMN1, TRY_CONVERT(xml, COLUMN2).value('.', 'nvarchar(max)') as COL2, COLUMN3

Android SeekBar setOnSeekBarChangeListener

onProgressChanged() should be called on every progress changed, not just on first and last touch (that why you have onStartTrackingTouch() and onStopTrackingTouch() methods).

Make sure that your SeekBar have more than 1 value, that is to say your MAX>=3.

In your onCreate:

 yourSeekBar=(SeekBar) findViewById(;
 yourSeekBar.setOnSeekBarChangeListener(new yourListener());

Your listener:

private class yourListener implements SeekBar.OnSeekBarChangeListener {

        public void onProgressChanged(SeekBar seekBar, int progress,
                boolean fromUser) {
                            // Log the progress
            Log.d("DEBUG", "Progress is: "+progress);
                            //set textView's text

        public void onStartTrackingTouch(SeekBar seekBar) {}

        public void onStopTrackingTouch(SeekBar seekBar) {}


Please share some code and the Log results for furter help.

Get checkbox values using checkbox name using jquery

// get checkbox values using checkbox's name

        function getCheckBoxValues(){
            $('[name="checkname"]').each( function (){
        <input type="checkbox" name="checkname" value='1'/>
        <input type="checkbox" name="checkname" value='2'/>
        <input type="checkbox" name="checkname" value='3'/>
        <input type="button" value="CheckBoxValues" onclick="getCheckBoxValues()"/>

// get only the values witch are checked

function getCheckBoxValues(){
        $('[name="checkname"]').each( function (){
            if($(this).prop('checked') == true){

What dependency is missing for org.springframework.web.bind.annotation.RequestMapping?

Add this below dependency in your pom.xml


This is used for @RestController, @RequestMapping

Mockito: Trying to spy on method is calling the original method

The answer by Tomasz Nurkiewicz appears not to tell the whole story!

NB Mockito version: 1.10.19.

I am very much a Mockito newb, so can't explain the following behaviour: if there's an expert out there who can improve this answer, please feel free.

The method in question here, getContentStringValue, is NOT final and NOT static.

This line does call the original method getContentStringValue:

doReturn( "dummy" ).when( im ).getContentStringValue( anyInt(), isA( ScoreDoc.class ));

This line does not call the original method getContentStringValue:

doReturn( "dummy" ).when( im ).getContentStringValue( anyInt(), any( ScoreDoc.class ));

For reasons which I can't answer, using isA() causes the intended (?) "do not call method" behaviour of doReturn to fail.

Let's look at the method signatures involved here: they are both static methods of Matchers. Both are said by the Javadoc to return null, which is a little difficult to get your head around in itself. Presumably the Class object passed as the parameter is examined but the result either never calculated or discarded. Given that null can stand for any class and that you are hoping for the mocked method not to be called, couldn't the signatures of isA( ... ) and any( ... ) just return null rather than a generic parameter* <T>?


public static <T> T isA(java.lang.Class<T> clazz)

public static <T> T any(java.lang.Class<T> clazz)

The API documentation does not give any clue about this. It also seems to say the need for such "do not call method" behaviour is "very rare". Personally I use this technique all the time: typically I find that mocking involves a few lines which "set the scene" ... followed by calling a method which then "plays out" the scene in the mock context which you have staged... and while you are setting up the scenery and the props the last thing you want is for the actors to enter stage left and start acting their hearts out...

But this is way beyond my pay grade... I invite explanations from any passing Mockito high priests...

* is "generic parameter" the right term?

Javascript: How to pass a function with string parameters as a parameter to another function

Try this:


Then you just need to call these two functions passed to myfunction:

function myfunction(url, f1, f2) {
    // …

CSS: transition opacity on mouse-out?

$(window).scroll(function() {    
    $('.logo_container, .slogan').css({
        "opacity" : ".1",
        "transition" : "opacity .8s ease-in-out"

Check the fiddle:

Fully backup a git repo?

cd /path/to/backupdir/
git clone /path/to/repo
cd /path/to/repo
git remote add backup /path/to/backupdir
git push --set-upstream backup master

this creates a backup and makes the setup, so that you can do a git push to update your backup, what is probably what you want to do. Just make sure, that /path/to/backupdir and /path/to/repo are at least different hard drives, otherwise it doesn't make that much sense to do that.

HAX kernel module is not installed

Try installing it again with the stand alone installer - assuming you have a CPU that supports Virtualization, have turned off antivirus and any hypervisor.

How to stop an unstoppable zombie job on Jenkins without restarting the server?

Had this same issue but there was not stack thread. We deleted the job by using this snippet in the Jenkins Console. Replace jobname and buil dnumber with yours.

def jobname = "Main/FolderName/BuildDefinition"
def buildnum = 6

How do I use .woff fonts for my website?

After generation of woff files, you have to define font-family, which can be used later in all your css styles. Below is the code to define font families (for normal, bold, bold-italic, italic) typefaces. It is assumed, that there are 4 *.woff files (for mentioned typefaces), placed in fonts subdirectory.

In CSS code:

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font.woff") format('woff');

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font-bold.woff") format('woff');
    font-weight: bold;

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font-boldoblique.woff") format('woff');
    font-weight: bold;
    font-style: italic;

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font-oblique.woff") format('woff');
    font-style: italic;

After having that definitions, you can just write, for example,

In HTML code:

<div class="mydiv">
    <b>this will be written with awesome-font-bold.woff</b>
    <b><i>this will be written with awesome-font-boldoblique.woff</i></b>
    <i>this will be written with awesome-font-oblique.woff</i>
    this will be written with awesome-font.woff

In CSS code:

.mydiv {
    font-family: myfont

The good tool for generation woff files, which can be included in CSS stylesheets is located here. Not all woff files work correctly under latest Firefox versions, and this generator produces 'correct' fonts.

How to get last inserted row ID from WordPress database?

just like this :

global $wpdb;
$results = $wpdb->get_results("SELECT * FROM $table_name ORDER BY ID DESC LIMIT 1");

simply your selecting all the rows then order them DESC by id , and displaying only the first

Component is not part of any NgModule or the module has not been imported into your module

In my case, I only need to restart the server (that is if you're using ng serve).

It happens to me every time I add a new module while the server is running.

Oracle Insert via Select from multiple tables where one table may not have a row

Outter joins don't work "as expected" in that case because you have explicitly told Oracle you only want data if that criteria on that table matches. In that scenario, the outter join is rendered useless.

A work-around

INSERT INTO account_type_standard 
  (account_type_Standard_id, tax_status_id, recipient_id) 
  (SELECT account_type_standard_seq.nextval FROM DUAL),
  (SELECT tax_status_id FROM tax_status WHERE tax_status_code = ?), 
  (SELECT recipient_id FROM recipient WHERE recipient_code = ?)

[Edit] If you expect multiple rows from a sub-select, you can add ROWNUM=1 to each where clause OR use an aggregate such as MAX or MIN. This of course may not be the best solution for all cases.

[Edit] Per comment,

  (SELECT account_type_standard_seq.nextval FROM DUAL),

can be just


Created Button Click Event c#

Create the Button and add it to Form.Controls list to display it on your form:

Button buttonOk = new Button();
buttonOk.Location = new Point(295, 45);  //or what ever position you want it to give
buttonOk.Text = "OK"; //or what ever you want to write over it
buttonOk.Click += new EventHandler(buttonOk_Click);
this.Controls.Add(buttonOk); //here you add it to the Form's Controls list

Create the button click method here:

void buttonOk_Click(object sender, EventArgs e)
            this.Close(); //all your choice to close it or remove this line

How do I set the default Java installation/runtime (Windows)?

I have patched the behaviour of my eclipse startup shortcut in the properties dialogue


"E:\Program Files\eclipse\eclipse.exe"


"E:\Program Files\eclipse\eclipse.exe" -vm "E:\Program Files\Java\jdk1.6.0_30\bin"

as described in the Eclipse documentation

It is a patch only, as it depends on the shortcut to fix things...

The alternative is to set the parameter permanently in the eclipse initialisation file.

How to execute an external program from within Node.js?

The simplest way is:

const { exec } = require("child_process")

unref is necessary to end your process without waiting for "yourApp"

Here are the exec docs

Open an html page in default browser with VBA?

If you want a more robust solution with ShellExecute that will open ANY file, folder or URL using the default OS associated program to do so, here is a function taken from

'************ Code Start **********
' This code was originally written by Dev Ashish.
' It is not to be altered or distributed,
' except as part of an application.
' You are free to use it in any application,
' provided the copyright notice is left unchanged.
' Code Courtesy of
' Dev Ashish
Private Declare Function apiShellExecute Lib "shell32.dll" _
    Alias "ShellExecuteA" _
    (ByVal hwnd As Long, _
    ByVal lpOperation As String, _
    ByVal lpFile As String, _
    ByVal lpParameters As String, _
    ByVal lpDirectory As String, _
    ByVal nShowCmd As Long) _
    As Long

'***App Window Constants***
Public Const WIN_NORMAL = 1         'Open Normal
Public Const WIN_MAX = 3            'Open Maximized
Public Const WIN_MIN = 2            'Open Minimized

'***Error Codes***
Private Const ERROR_SUCCESS = 32&
Private Const ERROR_NO_ASSOC = 31&
Private Const ERROR_OUT_OF_MEM = 0&
Private Const ERROR_FILE_NOT_FOUND = 2&
Private Const ERROR_PATH_NOT_FOUND = 3&
Private Const ERROR_BAD_FORMAT = 11&

'***************Usage Examples***********************
'Open a folder:     ?fHandleFile("C:\TEMP\",WIN_NORMAL)
'Call Email app:    ?fHandleFile("mailto:[email protected]",WIN_NORMAL)
'Open URL:          ?fHandleFile("", WIN_NORMAL)
'Handle Unknown extensions (call Open With Dialog):
'                   ?fHandleFile("C:\TEMP\TestThis",Win_Normal)
'Start Access instance:
'                   ?fHandleFile("I:\mdbs\CodeNStuff.mdb", Win_NORMAL)

Function fHandleFile(stFile As String, lShowHow As Long)
Dim lRet As Long, varTaskID As Variant
Dim stRet As String
    'First try ShellExecute
    lRet = apiShellExecute(hWndAccessApp, vbNullString, _
            stFile, vbNullString, vbNullString, lShowHow)

    If lRet > ERROR_SUCCESS Then
        stRet = vbNullString
        lRet = -1
        Select Case lRet
            Case ERROR_NO_ASSOC:
                'Try the OpenWith dialog
                varTaskID = Shell("rundll32.exe shell32.dll,OpenAs_RunDLL " _
                        & stFile, WIN_NORMAL)
                lRet = (varTaskID <> 0)
            Case ERROR_OUT_OF_MEM:
                stRet = "Error: Out of Memory/Resources. Couldn't Execute!"
            Case ERROR_FILE_NOT_FOUND:
                stRet = "Error: File not found.  Couldn't Execute!"
            Case ERROR_PATH_NOT_FOUND:
                stRet = "Error: Path not found. Couldn't Execute!"
            Case ERROR_BAD_FORMAT:
                stRet = "Error:  Bad File Format. Couldn't Execute!"
            Case Else:
        End Select
    End If
    fHandleFile = lRet & _
                IIf(stRet = "", vbNullString, ", " & stRet)
End Function
'************ Code End **********

Just put this into a separate module and call fHandleFile() with the right parameters.

Method to Add new or update existing item in Dictionary

Functionally, they are equivalent.

Performance-wise map[key] = value would be quicker, as you are only making single lookup instead of two.

Style-wise, the shorter the better :)

The code will in most cases seem to work fine in multi-threaded context. It however is not thread-safe without extra synchronization.

Dialog throwing "Unable to add window — token null is not for an application” with getApplication() as context

For future readers, this should help:

public void show() {
    if(mContext instanceof Activity) {
        Activity activity = (Activity) mContext;
        if (!activity.isFinishing() && !activity.isDestroyed()) {

What are the alternatives now that the Google web search API has been deprecated?

You could just send them through like a browser does, and then parse the html, that is what I have always done, even for things like Youtube.

Add a custom attribute to a Laravel / Eloquent model on load?

Let say you have 2 columns named first_name and last_name in your users table and you want to retrieve full name. you can achieve with the following code :

class User extends Eloquent {

    public function getFullNameAttribute()
        return $this->first_name.' '.$this->last_name;

now you can get full name as:

$user = User::find(1);

Could not find module "@angular-devkit/build-angular"

npm install Just type npm install and run.Then the project will run without errors. Or you can use npm install --save-dev @angular-devkit/build-angular

Delayed function calls

I've been looking for something like this myself - I came up with the following, although it does use a timer, it uses it only once for the initial delay, and doesn't require any Sleep calls ...

public void foo()
    System.Threading.Timer timer = null; 
    timer = new System.Threading.Timer((obj) =>
                null, 1000, System.Threading.Timeout.Infinite);

public void bar()
    // do stuff

(thanks to Fred Deschenes for the idea of disposing the timer within the callback)


Hai sridhar, I found an answer for your prob

ClientScript.RegisterClientScriptBlock(GetType(), "sas", "<script> alert('Inserted successfully');</script>", true);

change false to true

or try this

ScriptManager.RegisterClientScriptBlock(ursavebuttonID, typeof(LinkButton or button), "sas", "<script> alert('Inserted successfully');</script>", true);

What is RSS and VSZ in Linux memory management

RSS is Resident Set Size (physically resident memory - this is currently occupying space in the machine's physical memory), and VSZ is Virtual Memory Size (address space allocated - this has addresses allocated in the process's memory map, but there isn't necessarily any actual memory behind it all right now).

Note that in these days of commonplace virtual machines, physical memory from the machine's view point may not really be actual physical memory.

How can I reverse a list in Python?

>>> l = [1, 2, 3, 4, 5]
>>> print(reduce(lambda acc, x: [x] + acc, l, []))
[5, 4, 3, 2, 1]

Changing directory in Google colab (breaking out of the python interpreter)

Use os.chdir. Here's a full example:


!mkdir abc
!echo "file" > abc/123.txt

import os

# Now the directory 'abc' is the current working directory.
# and will show 123.txt.

What are the rules for JavaScript's automatic semicolon insertion (ASI)?

Straight from the ECMA-262, Fifth Edition ECMAScript Specification:

7.9.1 Rules of Automatic Semicolon Insertion

There are three basic rules of semicolon insertion:

  1. When, as the program is parsed from left to right, a token (called the offending token) is encountered that is not allowed by any production of the grammar, then a semicolon is automatically inserted before the offending token if one or more of the following conditions is true:
    • The offending token is separated from the previous token by at least one LineTerminator.
    • The offending token is }.
  2. When, as the program is parsed from left to right, the end of the input stream of tokens is encountered and the parser is unable to parse the input token stream as a single complete ECMAScript Program, then a semicolon is automatically inserted at the end of the input stream.
  3. When, as the program is parsed from left to right, a token is encountered that is allowed by some production of the grammar, but the production is a restricted production and the token would be the first token for a terminal or nonterminal immediately following the annotation "[no LineTerminator here]" within the restricted production (and therefore such a token is called a restricted token), and the restricted token is separated from the previous token by at least one LineTerminator, then a semicolon is automatically inserted before the restricted token.

However, there is an additional overriding condition on the preceding rules: a semicolon is never inserted automatically if the semicolon would then be parsed as an empty statement or if that semicolon would become one of the two semicolons in the header of a for statement (see 12.6.3).

Difference between arguments and parameters in Java

They are not. They're exactly the same.

However, some people say that parameters are placeholders in method signatures:

public void doMethod(String s, int i) {

String s and int i are sometimes said to be parameters. The arguments are the actual values/references:

myClassReference.doMethod("someString", 25);

"someString" and 25 are sometimes said to be the arguments.

Amazon S3 direct file upload from client browser - private key disclosure

Adding more info to the accepted answer, you can refer to my blog to see a running version of the code, using AWS Signature version 4.

Will summarize here:

As soon as the user selects a file to be uploaded, do the followings: 1. Make a call to the web server to initiate a service to generate required params

  1. In this service, make a call to AWS IAM service to get temporary cred

  2. Once you have the cred, create a bucket policy (base 64 encoded string). Then sign the bucket policy with the temporary secret access key to generate final signature

  3. send the necessary parameters back to the UI

  4. Once this is received, create a html form object, set the required params and POST it.

For detailed info, please refer

How to use the pass statement?

Python has the syntactical requirement that code blocks (after if, except, def, class etc.) cannot be empty. Empty code blocks are however useful in a variety of different contexts, such as in examples below, which are the most frequent use cases I have seen.

Therefore, if nothing is supposed to happen in a code block, a pass is needed for such a block to not produce an IndentationError. Alternatively, any statement (including just a term to be evaluated, like the Ellipsis literal ... or a string, most often a docstring) can be used, but the pass makes clear that indeed nothing is supposed to happen, and does not need to be actually evaluated and (at least temporarily) stored in memory.

  • Ignoring (all or) a certain type of Exception (example from xml):

        self.version = "Expat %d.%d.%d" % expat.version_info
    except AttributeError:
        pass # unknown

    Note: Ignoring all types of raises, as in the following example from pandas, is generally considered bad practice, because it also catches exceptions that should probably be passed on to the caller, e.g. KeyboardInterrupt or SystemExit (or even HardwareIsOnFireError – How do you know you aren't running on a custom box with specific errors defined, which some calling application would want to know about?).


    Instead using at least except Error: or in this case preferably except OSError: is considered much better practice. A quick analysis of all python modules I have installed gave me that more than 10% of all except ...: pass statements catch all exceptions, so it's still a frequent pattern in python programming.

  • Deriving an exception class that does not add new behaviour (e.g. in scipy):

    class CompileError(Exception):

    Similarly, classes intended as abstract base class often have an explicit empty __init__ or other methods that subclasses are supposed to derive. (e.g. pebl)

    class _BaseSubmittingController(_BaseController):
        def submit(self, tasks): pass
        def retrieve(self, deferred_results): pass
  • Testing that code runs properly for a few test values, without caring about the results (from mpmath):

    for x, error in MDNewton(mp, f, (1,-2), verbose=0,
                             norm=lambda x: norm(x, inf)):
  • In class or function definitions, often a docstring is already in place as the obligatory statement to be executed as the only thing in the block. In such cases, the block may contain pass in addition to the docstring in order to say “This is indeed intended to do nothing.”, for example in pebl:

    class ParsingError(Exception): 
        """Error encountered while parsing an ill-formed datafile."""
  • In some cases, pass is used as a placeholder to say “This method/class/if-block/... has not been implemented yet, but this will be the place to do it”, although I personally prefer the Ellipsis literal ... in order to strictly differentiate between this and the intentional “no-op” in the previous example. (Note that the Ellipsis literal is a valid expression only in Python 3)
    For example, if I write a model in broad strokes, I might write

    def update_agent(agent):

    where others might have

    def update_agent(agent):


    def time_step(agents):
        for agent in agents:

    as a reminder to fill in the update_agent function at a later point, but run some tests already to see if the rest of the code behaves as intended. (A third option for this case is raise NotImplementedError. This is useful in particular for two cases: Either “This abstract method should be implemented by every subclass, there is no generic way to define it in this base class”, or “This function, with this name, is not yet implemented in this release, but this is what its signature will look like”)

jQuery click not working for dynamically created items

I faced this problem a few days ago - the solution for me was to use .bind() to bind the required function to the dynamically created link.

var catLink = $('<a href="#" id="' + i + '" class="lnkCat">' + category.category + '</a>');
catLink.bind("click", function(){

getSubCategories : function(obj) {
 //do something

I hope this helps.

Counter in foreach loop in C#

Or even more simple if you don't want to use a lot of linq and for some reason don't want to use a for loop.

int i = 0;
foreach(var x in arr)
   //Do some stuff

What is a regular expression for a MAC Address?

This regex matches pretty much every mac format including Cisco format such as 0102-0304-abcd


Example strings which it matches:


Mixed format will be matched also!

Send json post using php

use CURL luke :) seriously, thats one of the best ways to do it AND you get the response.

Xcode: Could not locate device support files

  1. Download & mount I was first wandered if it could be mounted directly through hdiutil attach and looks like it could but not for everyone's accounts.

  2. Open to see its content and copy Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/7.1 to same path into Xcode application directory.

  3. Restart Xcode

How do I get the XML root node with C#?

I got the same question here. If the document is huge, it is not a good idea to use XmlDocument. The fact is that the first element is the root element, based on which XmlReader can be used to get the root element. Using XmlReader will be much more efficient than using XmlDocument as it doesn't require load the whole document into memory.

  using (XmlReader reader = XmlReader.Create(<your_xml_file>)) {
    while (reader.Read()) {
      // first element is the root element
      if (reader.NodeType == XmlNodeType.Element) {

How do I find the CPU and RAM usage using PowerShell?

I use the following PowerShell snippet to get CPU usage for local or remote systems:

Get-Counter -ComputerName localhost '\Process(*)\% Processor Time' | Select-Object -ExpandProperty countersamples | Select-Object -Property instancename, cookedvalue| Sort-Object -Property cookedvalue -Descending| Select-Object -First 20| ft InstanceName,@{L='CPU';E={($_.Cookedvalue/100).toString('P')}} -AutoSize

Same script but formatted with line continuation:

Get-Counter -ComputerName localhost '\Process(*)\% Processor Time' `
    | Select-Object -ExpandProperty countersamples `
    | Select-Object -Property instancename, cookedvalue `
    | Sort-Object -Property cookedvalue -Descending | Select-Object -First 20 `
    | ft InstanceName,@{L='CPU';E={($_.Cookedvalue/100).toString('P')}} -AutoSize

On a 4 core system it will return results that look like this:

InstanceName          CPU
------------          ---
_total                399.61 %
idle                  314.75 %
system                26.23 %
services              24.69 %
setpoint              15.43 %
dwm                   3.09 %
policy.client.invoker 3.09 %
imobilityservice      1.54 %
mcshield              1.54 %
hipsvc                1.54 %
svchost               1.54 %
stacsv64              1.54 %
wmiprvse              1.54 %
chrome                1.54 %
dbgsvc                1.54 %
sqlservr              0.00 %
wlidsvc               0.00 %
iastordatamgrsvc      0.00 %
intelmefwservice      0.00 %
lms                   0.00 %

The ComputerName argument will accept a list of servers, so with a bit of extra formatting you can generate a list of top processes on each server. Something like:

$psstats = Get-Counter -ComputerName utdev1,utdev2,utdev3 '\Process(*)\% Processor Time' -ErrorAction SilentlyContinue | Select-Object -ExpandProperty countersamples | %{New-Object PSObject -Property @{ComputerName=$_.Path.Split('\')[2];Process=$_.instancename;CPUPct=("{0,4:N0}%" -f $_.Cookedvalue);CookedValue=$_.CookedValue}} | ?{$_.CookedValue -gt 0}| Sort-Object @{E='ComputerName'; A=$true },@{E='CookedValue'; D=$true },@{E='Process'; A=$true }
$psstats | ft @{E={"{0,25}" -f $_.Process};L="ProcessName"},CPUPct -AutoSize -GroupBy ComputerName -HideTableHeaders

Which would result in a $psstats variable with the raw data and the following display:

   ComputerName: utdev1

           _total  397%
             idle  358%
             3mws   28%
           webcrs   10%

   ComputerName: utdev2

           _total  400%
             idle  248%
             cpfs   42%
             cpfs   36%
             cpfs   34%
          svchost   21%
         services   19%

   ComputerName: utdev3

           _total  200%
             idle  200%

How to install the JDK on Ubuntu Linux

Have a look at OpenJDK. It is the standard JVM implementation on Linux.

E11000 duplicate key error index in mongodb mongoose

Check collection indexes.

I had that issue due to outdated indexes in collection for fields, which should be stored by different new path.

Mongoose adds index, when you specify field as unique.

How to resolve Nodejs: Error: ENOENT: no such file or directory

I also had this issue because I had another console window open that was running the app and I was attempting to re-run yarn start in another console window.

The first yarn executing prevented the second from writing. So I just killed the first process and it worked

Display array values in PHP

Other option:

echo $lijst[$i];
echo "<br>";

How do I detect IE 8 with jQuery?


1) $.browser appears to be dropped in jQuery 1.9+ (as noted by Mandeep Jain). It is recommended to use .support instead.

2) $.browser.version can return "7" in IE >7 when the browser is in "compatibility" mode.

3) As of IE 10, conditional comments will no longer work.

4) jQuery 2.0+ will drop support for IE 6/7/8

5) document.documentMode appears to be defined only in Internet Explorer 8+ browsers. The value returned will tell you in what "compatibility" mode Internet Explorer is running. Still not a good solution though.

I tried numerous .support() options, but it appears that when an IE browser (9+) is in compatibility mode, it will simply behave like IE 7 ... :(

So far I only found this to work (kind-a):

(if documentMode is not defined and htmlSerialize and opacity are not supported, then you're very likely looking at IE <8 ...)

if(!document.documentMode && !$.support.htmlSerialize && !$.support.opacity) 
    // IE 6/7 code

What is the difference between id and class in CSS, and when should I use them?

IDs must be unique--you can't have more than one element with the same ID in an html document. Classes can be used for multiple elements. In this case, you would want to use an ID for "main" because it's (presumably) unique--it's the "main" div that serves as a container for your other content and there will only be one.

If you have a bunch of menu buttons or some other element for which you want the styling repeated, you would assign them all to the same class and then style that class.

Is it possible to get an Excel document's row count without loading the entire document into memory? see : row_range() Utility function to get row range

if you use pyexcel, can call row_range get max rows.

python 3.4 test pass.

Simple DateTime sql query

 WHERE [DateTime] >= '2011-04-12 12:00:00 AM'
   AND [DateTime] <= '2011-05-25 3:35:04 AM'

If this doesn't work, please script out your table and post it here. this will help us get you the correct answer quickly.

Replacing H1 text with a logo image: best method for SEO and accessibility?

One point no one has touched on is the fact that the h1 attribute should be specific to every page and using the site logo will effectively replicate the H1 on every page of the site.

I like to use a z index hidden h1 for each page as the best SEO h1 is often not the best for sales or aesthetic value.

Create a folder if it doesn't already exist

We should always modularise our code and I've written the same check it below... We first check the directory, if the directory is absent we create the directory.

$boolDirPresents = $this->CheckDir($DirectoryName);

if (!$boolDirPresents) {
        $boolCreateDirectory = $this->CreateDirectory($DirectoryName);
        if ($boolCreateDirectory) {
        echo "Created successfully";

function CheckDir($DirName) {
    if (file_exists($DirName)) {
        echo "Dir Exists<br>";
        return true;
    } else {
        echo "Dir Not Absent<br>";
        return false;

function CreateDirectory($DirName) {
    if (mkdir($DirName, 0777)) {
        return true;
    } else {
        return false;

How Can I Remove “public/index.php” in the URL Generated Laravel?

I just installed Laravel 5 for a project and there is a file in the root called server.php.

Change it to index.php and it works or type in terminal:

$cp server.php index.php

How to set layout_weight attribute dynamically from code?

You can pass it in as part of the LinearLayout.LayoutParams constructor:

LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(

The last parameter is the weight.

How to fix itunes could not connect to the iphone because an invalid response was received from the device?

Try resetting your network settings

Settings -> General -> Reset -> Reset Network Settings

And try deleting the contents of your mac/pc lockdown folder. Here's the link, follow the steps on "Reset the Lockdown folder".

This one worked for me.

How to define a Sql Server connection string to use in VB.NET?

Standard Security:

Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;

Trusted Connection:


will be glad if it helps.


Exception thrown inside catch block - will it be caught again?

The Java Language Specification says in section 14.19.1:

If execution of the try block completes abruptly because of a throw of a value V, then there is a choice:

  • If the run-time type of V is assignable to the Parameter of any catch clause of the try statement, then the first (leftmost) such catch clause is selected. The value V is assigned to the parameter of the selected catch clause, and the Block of that catch clause is executed. If that block completes normally, then the try statement completes normally; if that block completes abruptly for any reason, then the try statement completes abruptly for the same reason.


In other words, the first enclosing catch that can handle the exception does, and if an exception is thrown out of that catch, that's not in the scope of any other catch for the original try, so they will not try to handle it.

One related and confusing thing to know is that in a try-[catch]-finally structure, a finally block may throw an exception and if so, any exception thrown by the try or catch block is lost. That can be confusing the first time you see it.

What is the difference between server side cookie and client side cookie?


Cookies are key/value pairs used by websites to store state information on the browser. Say you have a website (, when the browser requests a webpage the website can send cookies to store information on the browser.

Browser request example:

GET /index.html HTTP/1.1

Example answer from the server:

HTTP/1.1 200 OK
Content-type: text/html
Set-Cookie: foo=10
Set-Cookie: bar=20; Expires=Fri, 30 Sep 2011 11:48:00 GMT
... rest  of the response

Here two cookies foo=10 and bar=20 are stored on the browser. The second one will expire on 30 September. In each subsequent request the browser will send the cookies back to the server.

GET /spec.html HTTP/1.1
Cookie: foo=10; bar=20
Accept: */*

SESSIONS: Server side cookies

Server side cookies are known as "sessions". The website in this case stores a single cookie on the browser containing a unique Session Identifier. Status information (foo=10 and bar=20 above) are stored on the server and the Session Identifier is used to match the request with the data stored on the server.

Examples of usage

You can use both sessions and cookies to store: authentication data, user preferences, the content of a chart in an e-commerce website, etc...

Pros and Cons

Below pros and cons of the solutions. These are the first that comes to my mind, there are surely others.

Cookie Pros:

  • scalability: all the data is stored in the browser so each request can go through a load balancer to different webservers and you have all the information needed to fullfill the request;
  • they can be accessed via javascript on the browser;
  • not being on the server they will survive server restarts;
  • RESTful: requests don't depend on server state

Cookie Cons:

Session Pros:

  • generally easier to use, in PHP there's probably not much difference.
  • unlimited storage

Session Cons:

  • more difficult to scale
  • on web server restarts you can lose all sessions or not depending on the implementation
  • not RESTful

JOptionPane YES/No Options Confirm Dialog Box Issue

int opcion = JOptionPane.showConfirmDialog(null, "Realmente deseas salir?", "Aviso", JOptionPane.YES_NO_OPTION);

if (opcion == 0) { //The ISSUE is here
} else {

How to place div in top right hand corner of page

the style is:

<style type="text/css">

hope it will work. Thanks

How to secure database passwords in PHP?

Put the database password in a file, make it read-only to the user serving the files.

Unless you have some means of only allowing the php server process to access the database, this is pretty much all you can do.

How do you rename a Git tag?

The original question was how to rename a tag, which is easy: first create NEW as an alias of OLD: git tag NEW OLD then delete OLD: git tag -d OLD.

The quote regarding "the Git way" and (in)sanity is off base, because it's talking about preserving a tag name, but making it refer to a different repository state.

Eclipse error ... cannot be resolved to a type

Also If you are using mavenised project then try to update your project by clicking Alt+F5. Or right click on the application and go to maven /update project.

It builds all your components and resolves if any import error is there.

React onClick function fires on render

I had similar issue, my code was:

function RadioInput(props) {
    return (
    <div className="form-check form-check-inline">
        <input className="form-check-input" type="radio" name="inlineRadioOptions" id={} onClick={props.onClick} value={props.label}></input>
        <label className="form-check-label" htmlFor={}>{props.label}</label>
class ScheduleType extends React.Component
        id = "inlineRadio"+id;
                id = {id}
                label = {label}
                onClick = {this.props.onClick}


Where it should be

onClick = {() => this.props.onClick()}

in RenderRadioInput

It fixed the issue for me.

Excel formula to search if all cells in a range read "True", if not, then show "False"

As it appears you have the values as text, and not the numeric True/False, then you can use either COUNTIF or SUMPRODUCT


How do I remove my IntelliJ license in 2019.3?

For PHPStorm 2020.3.2 on ubuntu inorder to reset expiration license, you should run following commands:

sudo rm ~/.config/JetBrains/PhpStorm2020.3/options/other.xml 
sudo rm ~/.config/JetBrains/PhpStorm2020.3/eval/*          
sudo rm -rf .java/.userPrefs

Property 'catch' does not exist on type 'Observable<any>'

In angular 8:

//for catch:
import { catchError } from 'rxjs/operators';

//for throw:
import { Observable, throwError } from 'rxjs';

//and code should be written like this.

getEmployees(): Observable<IEmployee[]> {
    return this.http.get<IEmployee[]>(this.url).pipe(catchError(this.erroHandler));

  erroHandler(error: HttpErrorResponse) {
    return throwError(error.message || 'server Error');

MySQL integer field is returned as string in PHP

I like mastermind's technique, but the coding can be simpler:

function cast_query_results($result): array
    if ($result === false)
      return null;

    $data = array();
    $fields = $result->fetch_fields();
    while ($row = $result->fetch_assoc()) {
      foreach ($fields as $field) {
        $fieldName = $field->name;
        $fieldValue = $row[$fieldName];
        if (!is_null($fieldValue))
            switch ($field->type) {
              case 3:
                $row[$fieldName] = (int)$fieldValue;
              case 4:
                $row[$fieldName] = (float)$fieldValue;
              // Add other type conversions as desired.
              // Strings are already strings, so don't need to be touched.
      array_push($data, $row);

    return $data;

I also added checking for query returning false rather than a result-set.
And checking for a row with a field that has a null value.
And if the desired type is a string, I don't waste any time on it - its already a string.

I don't bother using this in most php code; I just rely on php's automatic type conversion. But if querying a lot of data, to then perform arithmetic computations, it is sensible to cast to the optimal types up front.

Undo working copy modifications of one file in Git?

If it is already committed, you can revert the change for the file and commit again, then squash new commit with last commit.

How can you test if an object has a specific property?

For identifying which of the objects in an array have a property

$HasProperty = $ArrayOfObjects | Where-Object {$_.MyProperty}

string encoding and decoding?

That's because your input string can’t be converted according to the encoding rules (strict by default).

I don't know, but I always encoded using directly unicode() constructor, at least that's the ways at the official documentation:

unicode(your_str, errors="ignore")

How to change the default charset of a MySQL table?

You can change the default with an alter table set default charset but that won't change the charset of the existing columns. To change that you need to use a alter table modify column.

Changing the charset of a column only means that it will be able to store a wider range of characters. Your application talks to the db using the mysql client so you may need to change the client encoding as well.

How do I set environment variables from Java?

Like most people who have found this thread, I was writing some unit tests and needed to modify the environment variables to set the correct conditions for the test to run. However, I found the most upvoted answers had some issues and/or were very cryptic or overly complicated. Hopefully this will help others to sort out the solution more quickly.

First off, I finally found @Hubert Grzeskowiak's solution to be the simplest and it worked for me. I wish I would have come to that one first. It's based on @Edward Campbell's answer, but without the complicating for loop search.

However, I started with @pushy's solution, which got the most upvotes. It is a combo of @anonymous and @Edward Campbell's. @pushy claims both approaches are needed to cover both Linux and Windows environments. I'm running under OS X and find that both work (once an issue with @anonymous approach is fixed). As others have noted, this solution works most of the time, but not all.

I think the source of most of the confusion comes from @anonymous's solution operating on the 'theEnvironment' field. Looking at the definition of the ProcessEnvironment structure, 'theEnvironment' is not a Map< String, String > but rather it is a Map< Variable, Value >. Clearing the map works fine, but the putAll operation rebuilds the map a Map< String, String >, which potentially causes problems when subsequent operations operate on the data structure using the normal API that expects Map< Variable, Value >. Also, accessing/removing individual elements is a problem. The solution is to access 'theEnvironment' indirectly through 'theUnmodifiableEnvironment'. But since this is a type UnmodifiableMap the access must be done through the private variable 'm' of the UnmodifiableMap type. See getModifiableEnvironmentMap2 in code below.

In my case I needed to remove some of the environment variables for my test (the others should be unchanged). Then I wanted to restore the environment variables to their prior state after the test. The routines below make that straight forward to do. I tested both versions of getModifiableEnvironmentMap on OS X, and both work equivalently. Though based on comments in this thread, one may be a better choice than the other depending on the environment.

Note: I did not include access to the 'theCaseInsensitiveEnvironmentField' since that seems to be Windows specific and I had no way to test it, but adding it should be straight forward.

private Map<String, String> getModifiableEnvironmentMap() {
    try {
        Map<String,String> unmodifiableEnv = System.getenv();
        Class<?> cl = unmodifiableEnv.getClass();
        Field field = cl.getDeclaredField("m");
        Map<String,String> modifiableEnv = (Map<String,String>) field.get(unmodifiableEnv);
        return modifiableEnv;
    } catch(Exception e) {
        throw new RuntimeException("Unable to access writable environment variable map.");

private Map<String, String> getModifiableEnvironmentMap2() {
    try {
        Class<?> processEnvironmentClass = Class.forName("java.lang.ProcessEnvironment");
        Field theUnmodifiableEnvironmentField = processEnvironmentClass.getDeclaredField("theUnmodifiableEnvironment");
        Map<String,String> theUnmodifiableEnvironment = (Map<String,String>)theUnmodifiableEnvironmentField.get(null);

        Class<?> theUnmodifiableEnvironmentClass = theUnmodifiableEnvironment.getClass();
        Field theModifiableEnvField = theUnmodifiableEnvironmentClass.getDeclaredField("m");
        Map<String,String> modifiableEnv = (Map<String,String>) theModifiableEnvField.get(theUnmodifiableEnvironment);
        return modifiableEnv;
    } catch(Exception e) {
        throw new RuntimeException("Unable to access writable environment variable map.");

private Map<String, String> clearEnvironmentVars(String[] keys) {

    Map<String,String> modifiableEnv = getModifiableEnvironmentMap();

    HashMap<String, String> savedVals = new HashMap<String, String>();

    for(String k : keys) {
        String val = modifiableEnv.remove(k);
        if (val != null) { savedVals.put(k, val); }
    return savedVals;

private void setEnvironmentVars(Map<String, String> varMap) {

public void myTest() {
    String[] keys = { "key1", "key2", "key3" };
    Map<String, String> savedVars = clearEnvironmentVars(keys);

    // do test


How to write and save html file in python?

You can try:

colour = ["red", "red", "green", "yellow"]

with open('mypage.html', 'w') as myFile:

    s = '1234567890'
    for i in range(0, len(s), 60):
        myFile.write('<tr><td>%04d</td>' % (i+1));
    for j, k in enumerate(s[i:i+60]):
        myFile.write('<td><font style="background-color:%s;">%s<font></td>' % (colour[j %len(colour)], k));


Navigation bar with UIImage for title

This worked for me... try it

let image : UIImage = UIImage(named: "LogoName")
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 25, height: 25))
imageView.contentMode = .scaleAspectFit
imageView.image = image
navigationItem.titleView = imageView

Why can I not create a wheel in python?

Update your setuptools, too.

pip install setuptools --upgrade

If that fails too, you could try with additional --force flag.

What is VanillaJS?

This is VanillaJS (unmodified):

// VanillaJS v1.0
// Released into the Public Domain
// Your code goes here:

As you can see, it's not really a framework or a library. It's just a running gag for framework-loving bosses or people who think you NEED to use a JS framework. It means you just use whatever your (for you own sake: non-legacy) browser gives you (using Vanilla JS when working with legacy browsers is a bad idea).

How to write an ArrayList of Strings into a text file?

I think you can also use BufferedWriter :

BufferedWriter writer = new BufferedWriter(new FileWriter(new File("note.txt")));

String stuffToWrite = info;



and before that remember too add


How to programmatically set the Image source

Use asp:image

<asp:Image id="Image1" runat="server"
           AlternateText="Image text"

and codebehind to change image url

Image1.ImageUrl = "/MyProject;component/Images/down.png"; 

How to create a custom-shaped bitmap marker with Android map API v2

I hope it still not too late to share my solution. Before that, you can follow the tutorial as stated in Android Developer documentation. To achieve this, you need to use Cluster Manager with defaultRenderer.

  1. Create an object that implements ClusterItem

    public class SampleJob implements ClusterItem {
    private double latitude;
    private double longitude;
    //Create constructor, getter and setter here
    public LatLng getPosition() {
        return new LatLng(latitude, longitude);
  2. Create a default renderer class. This is the class that do all the job (inflating custom marker/cluster with your own style). I am using Universal image loader to do the downloading and caching the image.

    public class JobRenderer extends DefaultClusterRenderer< SampleJob > {
    private final IconGenerator iconGenerator;
    private final IconGenerator clusterIconGenerator;
    private final ImageView imageView;
    private final ImageView clusterImageView;
    private final int markerWidth;
    private final int markerHeight;
    private final String TAG = "ClusterRenderer";
    private DisplayImageOptions options;
    public JobRenderer(Context context, GoogleMap map, ClusterManager<SampleJob> clusterManager) {
        super(context, map, clusterManager);
        // initialize cluster icon generator
        clusterIconGenerator = new IconGenerator(context.getApplicationContext());
        View clusterView = LayoutInflater.from(context).inflate(R.layout.multi_profile, null);
        clusterImageView = (ImageView) clusterView.findViewById(;
        // initialize cluster item icon generator
        iconGenerator = new IconGenerator(context.getApplicationContext());
        imageView = new ImageView(context.getApplicationContext());
        markerWidth = (int) context.getResources().getDimension(R.dimen.custom_profile_image);
        markerHeight = (int) context.getResources().getDimension(R.dimen.custom_profile_image);
        imageView.setLayoutParams(new ViewGroup.LayoutParams(markerWidth, markerHeight));
        int padding = (int) context.getResources().getDimension(R.dimen.custom_profile_padding);
        imageView.setPadding(padding, padding, padding, padding);
        options = new DisplayImageOptions.Builder()
    protected void onBeforeClusterItemRendered(SampleJob job, MarkerOptions markerOptions) {
        ImageLoader.getInstance().displayImage(job.getJobImageURL(), imageView, options);
        Bitmap icon = iconGenerator.makeIcon(job.getName());
    protected void onBeforeClusterRendered(Cluster<SampleJob> cluster, MarkerOptions markerOptions) {
        Iterator<Job> iterator = cluster.getItems().iterator();
        ImageLoader.getInstance().displayImage(, clusterImageView, options);
        Bitmap icon = clusterIconGenerator.makeIcon(;
    protected boolean shouldRenderAsCluster(Cluster cluster) {
        return cluster.getSize() > 1;
  3. Apply cluster manager in your activity/fragment class.

    public class SampleActivity extends AppCompatActivity implements OnMapReadyCallback {
    private ClusterManager<SampleJob> mClusterManager;
    private GoogleMap mMap;
    private ArrayList<SampleJob> jobs = new ArrayList<SampleJob>();
    protected void onCreate(Bundle savedInstanceState) {
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        mClusterManager = new ClusterManager<SampleJob>(this, mMap);
        mClusterManager.setRenderer(new JobRenderer(this, mMap, mClusterManager));
        //Assume that we already have arraylist of jobs
        for(final SampleJob job: jobs){
  4. Result


unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard

You can register a class for your UITableViewCell like this:

With Swift 3+:

self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")

With Swift 2.2:

self.tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")

Make sure same identifier "cell" is also copied at your storyboard's UITableViewCell.

"self" is for getting the class use the class name followed by .self.

How to get the mouse position without events (without moving the mouse)?

What you can do is create variables for the x and y coordinates of your cursor, update them whenever the mouse moves and call a function on an interval to do what you need with the stored position.

The downside to this of course is that at least one initial movement of the mouse is required to have it work. As long as the cursor updates its position at least once, we are able to find its position regardless of whether it moves again.

var cursor_x = -1;
var cursor_y = -1;
document.onmousemove = function(event)
 cursor_x = event.pageX;
 cursor_y = event.pageY;
setInterval(check_cursor, 1000);
function check_cursor(){console.log('Cursor at: '+cursor_x+', '+cursor_y);}

The preceding code updates once a second with a message of where your cursor is. I hope this helps.

align an image and some text on the same line without using div width?

U wrote an unnecessary div, just leave it like this

<div id="texts" style="white-space:nowrap;">
     <img src="tree.png"  align="left"/>
     A very long text(about 300 words) 

What u are looking for is white-space:nowrap; this code will do the trick.