How to sort ArrayList in Java in decreasing order?

Question

I am new in java i am trying to sort a list of install app in device according to their data use. i want like highest at the top.i use code to find install package are:

 List<ApplicationItem> mApplicationItemList = new ArrayList<ApplicationItem>();
    PackageManager p = getPackageManager();
    final List<PackageInfo> apps = p.getInstalledPackages(PackageManager.GET_PERMISSIONS);

            for (PackageInfo packageInfo : apps) {
                ApplicationItem item = new ApplicationItem();
                if (packageInfo.requestedPermissions == null)
                    continue;

                if (Arrays.asList(packageInfo.requestedPermissions).contains(android.Manifest.permission.INTERNET) &&
                        !Utility.isSystemApp(packageInfo.packageName) &&
                        (p.getLaunchIntentForPackage(packageInfo.packageName) != null)) {
                    item.setPkgName(packageInfo.packageName);
                    mApplicationItemList.add(item);
                }
            }
   and find data usage by this code:
public static long getTotalDataByUid(String pkgName) {
        long totalData = 0;
        try {
            ApplicationInfo appInfo = getApplicationContext().getPackageManager().getApplicationInfo(pkgName, 0);
            //TODO Handle UNSUPPORTED
            long tx = TrafficStats.getUidTxBytes(appInfo.uid);
            long rx = TrafficStats.getUidRxBytes(appInfo.uid);
            totalData = tx + rx;
            if (totalData < 0) {
                totalData = 0;
            }


        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
            totalData = 0;
        }
        return totalData;
    }

Here is a [similar question](http://stackoverflow.com/questions/6957631/sort-java-collection) to what you are trying to do — Shlomi Haver, Jul 08 '16 at 12:38
see this [How to sort ArrayList in descending order in Java](http://beginnersbook.com/2013/12/sort-arraylist-in-descending-order-in-java/) — FarshidABZ, Jul 08 '16 at 12:39

score 0 · Answer 1 · answered Jul 08 '16 at 12:41

0

use this method to sort arraylist

Comparator comparator = Collections.reverseOrder();
Collections.sort(YourarrayList,comparator);
System.out.println("After sorting ArrayList in descending order"+YourarrayList);

answered Jul 08 '16 at 12:41

Nitesh Pareek

362
2
10

app crash Caused by: java.lang.ClassCastException: mycustomClass$ApplicationItem cannot be cast to java.lang.Comparable – Sumit Jul 08 '16 at 12:45
public class ApplicationItem implements Comparable { @Override public int compareTo(Object o) { // comparison logic goes here } } – Nitesh Pareek Jul 08 '16 at 12:49
public class ApplicationItem implements Comparable { @Override public int compareTo(Object o) { // comparison logic goes here } } – Nitesh Pareek Jul 08 '16 at 12:56

How to sort ArrayList in Java in decreasing order?

1 Answers1