[java] Getting URL parameter in java and extract a specific text from that URL

I have a URL and I need to get the value of v from this URL. Here is my URL: http://www.youtube.com/watch?v=_RCIP6OrQrE

How can I do that?

Import these libraries

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;

Similar to the verisimilitude, but with the capabilities of handling multivalue parameters. Note: I've seen HTTP GET requests without a value, in this case the value will be null.

public static List<NameValuePair> getQueryMap(String query)  
{  
    List<NameValuePair> queryMap = new ArrayList<NameValuePair>();
    String[] params = query.split(Pattern.quote("&"));  
    for (String param : params)
    {
        String[] chunks = param.split(Pattern.quote("="));
        String name = chunks[0], value = null;  
        if(chunks.length > 1) {
            value = chunks[1];
        }
        queryMap.add(new BasicNameValuePair(name, value));
    }
    return queryMap;
}

Example:

GET /bottom.gif?e235c08=1509896923&%49%6E%...

I have something like this:

import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URIBuilder;

private String getParamValue(String link, String paramName) throws URISyntaxException {
        List<NameValuePair> queryParams = new URIBuilder(link).getQueryParams();
        return queryParams.stream()
                .filter(param -> param.getName().equalsIgnoreCase(paramName))
                .map(NameValuePair::getValue)
                .findFirst()
                .orElse("");
    }

Using pure Java 8

Assumming you want to extract param "v" from url:

             String paramV = Stream.of(url.split("?")[1].split("&"))
                        .map(kv -> kv.split("="))
                        .filter(kv -> "v".equalsIgnoreCase(kv[0]))
                        .map(kv -> kv[1])
                        .findFirst()
                        .orElse("");

I wrote this last month for Joomla Module when implementing youtube videos (with the Gdata API). I've since converted it to java.

Import These Libraries

    import java.net.URL;
    import java.util.regex.*;

Copy/Paste this function

    public String getVideoId( String videoId ) throws Exception {
        String pattern = "^(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]";
        Pattern p = Pattern.compile(pattern);
        Matcher m = p.matcher(videoId);
        int youtu = videoId.indexOf("youtu");
        if(m.matches() && youtu != -1){
            int ytu = videoId.indexOf("http://youtu.be/");
            if(ytu != -1) { 
                String[] split = videoId.split(".be/");
                return split[1];
            }
            URL youtube = new URL(videoId);
            String[] split = youtube.getQuery().split("=");
            int query = split[1].indexOf("&");
            if(query != -1){
                String[] nSplit = split[1].split("&");
                return nSplit[0];
            } else return split[1];
        }
        return null; //throw something or return what you want
    }

URL's it will work with

http://www.youtube.com/watch?v=k0BWlvnBmIE (General URL)
http://youtu.be/k0BWlvnBmIE (Share URL)
http://www.youtube.com/watch?v=UWb5Qc-fBvk&list=FLzH5IF4Lwgv-DM3CupM3Zog&index=2 (Playlist URL)

My solution mayble not good

        String url = "https://www.youtube.com/watch?param=test&v=XcHJMiSy_1c&lis=test";
        int start = url.indexOf("v=")+2;
        // int start = url.indexOf("list=")+5; **5 is length of ("list=")**
        int end = url.indexOf("&", start);

        end = (end == -1 ? url.length() : end); 

        System.out.println(url.substring(start, end));
        // result: XcHJMiSy_1c

work fine with:

• https://www.youtube.com/watch?param=test&v=XcHJMiSy_1c&lis=test
• https://www.youtube.com/watch?v=XcHJMiSy_1c

Assuming the URL syntax will always be http://www.youtube.com/watch?v= ...

String v = "http://www.youtube.com/watch?v=_RCIP6OrQrE".substring(31);

or disregarding the prefix syntax:

String url = "http://www.youtube.com/watch?v=_RCIP6OrQrE";
String v = url.substring(url.indexOf("v=") + 2);

If you're on Android, you can do this:

Uri uri = Uri.parse(url);
String v = uri.getQueryParameter("v");

public static String getQueryMap(String query) {        
    String[] params = query.split("&");     
    for (String param : params) {           
       String name = param.split("=")[0];
       if ("YourParam".equals(name)) {
           return param.split("=")[1]; 
       }
    }
    return null;
}

I believe we have a better approach to answer this question.

1: Define a function that returns Map values.

Here we go.

public Map<String, String> getUrlValues(String url) throws UnsupportedEncodingException {
    int i = url.indexOf("?");
    Map<String, String> paramsMap = new HashMap<>();
    if (i > -1) {
        String searchURL = url.substring(url.indexOf("?") + 1);
        String params[] = searchURL.split("&");

        for (String param : params) {
            String temp[] = param.split("=");
            paramsMap.put(temp[0], java.net.URLDecoder.decode(temp[1], "UTF-8"));
        }
    }

    return paramsMap;
}

2: Call your function surrounding with a try catch block

Here we go

try {
     Map<String, String> values = getUrlValues("https://example.com/index.php?form_id=9&page=1&view_id=78");
     String formId = values.get("form_id");
     String page = values.get("page");
     String viewId = values.get("view_id");
     Log.d("FormID", formId);
     Log.d("Page", page);
     Log.d("ViewID", viewId);
} catch (UnsupportedEncodingException e) {
     Log.e("Error", e.getMessage());
} 

I solved the problem like this

public static String getUrlParameterValue(String url, String paramName) {
String value = "";
List<NameValuePair> result = null;

try {
    result = URLEncodedUtils.parse(new URI(url), UTF_8);
    value = result.stream().filter(pair -> pair.getName().equals(paramName)).findFirst().get().getValue();
    System.out.println("-------------->  \n" + paramName + " : " + value + "\n");
} catch (URISyntaxException e) {
    e.printStackTrace();
} 
return value;

}

this will work for all sort of youtube url :
if url could be

youtube.com/?v=_RCIP6OrQrE
youtube.com/v/_RCIP6OrQrE
youtube.com/watch?v=_RCIP6OrQrE
youtube.com/watch?v=_RCIP6OrQrE&feature=whatever&this=that

Pattern p = Pattern.compile("http.*\\?v=([a-zA-Z0-9_\\-]+)(?:&.)*");
String url = "http://www.youtube.com/watch?v=_RCIP6OrQrE";
Matcher m = p.matcher(url.trim()); //trim to remove leading and trailing space if any

if (m.matches()) {
    url = m.group(1);        
}
System.out.println(url);

this will extract video id from your url

further reference

If you are using Jersey (which I was, my server component needs to make outbound HTTP requests) it contains the following public method:

var multiValueMap = UriComponent.decodeQuery(uri, true);

It is part of org.glassfish.jersey.uri.UriComponent, and the javadoc is here. Whilst you may not want all of Jersey, it is part of the Jersey common package which isn't too bad on dependencies...