I have an ArrayList
which stores Date
s and I sorted them in descending order. Now I want to display them in a ListView
. This is what I did so far:
spndata.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1,
int position, long arg3) {
switch (position) {
case 0:
list = DBAdpter.requestUserData(assosiatetoken);
for (int i = 0; i < list.size(); i++) {
if (list.get(i).lastModifiedDate != null) {
lv.setAdapter(new MyListAdapter(
getApplicationContext(), list));
}
}
break;
case 1:
list = DBAdpter.requestUserData(assosiatetoken);
Calendar c = Calendar.getInstance();
SimpleDateFormat df3 = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a");
String formattedDate3 = df3.format(c.getTime());
Log.v("log_tag", "Date " + formattedDate3);
for (int i = 0; i < list.size(); i++) {
if (list.get(i).submitDate != null) {
String sDate = list.get(i).submitDate;
SimpleDateFormat df4 = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a");
String formattedDate4 = df4.format(sDate);
Map<Date, Integer> dateMap = new TreeMap<Date, Integer>(new Comparator<Date>(){
public int compare(Date formattedDate3, Date formattedDate4) {
return formattedDate3.compareTo(formattedDate4);
}
});
lv.setAdapter(new MyListAdapter(
getApplicationContext(), list));
}
}
break;
case 2:
break;
case 3:
break;
default:
break;
}
}
public void onNothingSelected(AdapterView<?> arg0) {
}
});
This question is related to
java
android
date
arraylist
sortedlist
If date in string format convert it to date format for each object :
String argmodifiledDate = "2014-04-06 22:26:15";
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try
{
this.modifiledDate = format.parse(argmodifiledDate);
}
catch (ParseException e)
{
e.printStackTrace();
}
Then sort the arraylist in descending order :
ArrayList<Document> lstDocument= this.objDocument.getArlstDocuments();
Collections.sort(lstDocument, new Comparator<Document>() {
public int compare(Document o1, Document o2) {
if (o1.getModifiledDate() == null || o2.getModifiledDate() == null)
return 0;
return o2.getModifiledDate().compareTo(o1.getModifiledDate());
}
});
Easier alternative to above answers
If Object(Model Class/POJO) contains the date in String datatype.
private void sortArray(ArrayList<myObject> arraylist) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); //your own date format
if (reports != null) {
Collections.sort(arraylist, new Comparator<myObject>() {
@Override
public int compare(myObject o1, myObject o2) {
try {
return simpleDateFormat.parse(o2.getCreated_at()).compareTo(simpleDateFormat.parse(o1.getCreated_at()));
} catch (ParseException e) {
e.printStackTrace();
return 0;
}
}
});
}
If Object(Model Class/POJO) contains date in Date datatype
private void sortArray(ArrayList<myObject> arrayList) {
if (arrayList != null) {
Collections.sort(arrayList, new Comparator<myObject>() {
@Override
public int compare(myObject o1, myObject o2) {
return o2.getCreated_at().compareTo(o1.getCreated_at()); }
});
} }
The above code is for sorting the array in descending order of date, swap o1 and o2 for ascending order.
Date's compareTo() you're using will work for ascending order.
To do descending, just reverse the value of compareTo() coming out. You can use a single Comparator class that takes in a flag/enum in the constructor that identifies the sort order
public int compare(MyObject lhs, MyObject rhs) {
if(SortDirection.Ascending == m_sortDirection) {
return lhs.MyDateTime.compareTo(rhs.MyDateTime);
}
return rhs.MyDateTime.compareTo(lhs.MyDateTime);
}
You need to call Collections.sort() to actually sort the list.
As a side note, I'm not sure why you're defining your map inside your for loop. I'm not exactly sure what your code is trying to do, but I assume you want to populate the indexed values from your for loop in to the map.
Date
is Comparable
so just create list of List<Date>
and sort it using Collections.sort()
. And use Collections.reverseOrder()
to get comparator in reverse ordering
.
From Java Doc
Returns a comparator that imposes the reverse ordering of the specified comparator. If the specified comparator is null, this method is equivalent to reverseOrder() (in other words, it returns a comparator that imposes the reverse of the natural ordering on a collection of objects that implement the Comparable interface).
Just add like this in case 1: like this
case 0:
list = DBAdpter.requestUserData(assosiatetoken);
Collections.sort(list, byDate);
for (int i = 0; i < list.size(); i++) {
if (list.get(i).lastModifiedDate != null) {
lv.setAdapter(new MyListAdapter(
getApplicationContext(), list));
}
}
break;
and put this method at end of the your class
static final Comparator<All_Request_data_dto> byDate = new Comparator<All_Request_data_dto>() {
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a");
public int compare(All_Request_data_dto ord1, All_Request_data_dto ord2) {
Date d1 = null;
Date d2 = null;
try {
d1 = sdf.parse(ord1.lastModifiedDate);
d2 = sdf.parse(ord2.lastModifiedDate);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return (d1.getTime() > d2.getTime() ? -1 : 1); //descending
// return (d1.getTime() > d2.getTime() ? 1 : -1); //ascending
}
};
Source: Stackoverflow.com