When I opened Edit friends from menu, Application stopped

Question

I am new to this android development. Whenever I click on edit friends in my menu tab, application stops. This error is not generating on my logout tab. I am posting MainActivity, EditFriendsActivity and LogCat !

This is my EditFriendsActivity:

   package com.satty002.swag;

import java.util.List;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.widget.ArrayAdapter;

import com.parse.FindCallback;
import com.parse.ParseException;
import com.parse.ParseQuery;
import com.parse.ParseUser;

public class EditFriendsActivity extends ListActivity {

public static final String TAG = EditFriendsActivity.class.getSimpleName();

protected List<ParseUser> mUsers; 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
    setContentView(R.layout.activity_edit_friends);
}

@Override
protected void onResume() {
    super.onResume();

    setProgressBarIndeterminateVisibility(true);        
    ParseQuery<ParseUser> query = ParseUser.getQuery();
    query.orderByAscending(ParseConstants.KEY_USERNAME);
    query.setLimit(1000);
    query.findInBackground(new FindCallback<ParseUser>() {

        @Override
        public void done(List<ParseUser> users, ParseException e) {
            setProgressBarIndeterminateVisibility(false);       

            if (e == null) {
                //success
                users = mUsers;
                String[] usernames = new String[users.size()];
                int i = 0;
                for(ParseUser user : mUsers) {
                    usernames[i] = user.getUsername();
                    i++;
                }
                ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                        EditFriendsActivity.this, android.R.layout.simple_list_item_checked, usernames);
                setListAdapter(adapter);
            }
            else {
                Log.e(TAG, e.getMessage() );
                AlertDialog.Builder builder = new AlertDialog.Builder(EditFriendsActivity.this);
                builder.setMessage(e.getMessage())
                .setTitle(R.string.error_title)
                .setPositiveButton(android.R.string.ok, null);

                AlertDialog dialog = builder.create();
                dialog.show();

            }


        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.edit_friends, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
}

This is my MainActivity :

package com.satty002.swag;

import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.os.Bundle;
import android.support.v13.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

import com.parse.ParseAnalytics;
import com.parse.ParseUser;


public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

public static final String TAG = MainActivity.class.getSimpleName(); 

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link FragmentPagerAdapter} derivative, which will keep every
 * loaded fragment in memory. If this becomes too memory intensive, it
 * may be best to switch to a
 * {@link android.support.v13.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ParseAnalytics.trackAppOpened(getIntent());

    ParseUser currentUser = ParseUser.getCurrentUser();
    if (currentUser == null) {
        navigateToLogin();
    } else {
      Log.i(TAG, currentUser.getUsername());
    }


    // Set up the action bar.
    final ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    // When swiping between different sections, select the corresponding
    // tab. We can also use ActionBar.Tab#select() to do this if we have
    // a reference to the Tab.
    mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            actionBar.setSelectedNavigationItem(position);
        }
    });

    // For each of the sections in the app, add a tab to the action bar.
    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        // Create a tab with text corresponding to the page title defined by
        // the adapter. Also specify this Activity object, which implements
        // the TabListener interface, as the callback (listener) for when
        // this tab is selected.
        actionBar.addTab(
                actionBar.newTab()
                        .setText(mSectionsPagerAdapter.getPageTitle(i))
                        .setTabListener(this));
    }
}


private void navigateToLogin() {
    Intent intent = new Intent(this, LoginActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
    startActivity(intent);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_logout) {
        ParseUser.logOut();
        navigateToLogin();
        return true;
    }
    else if (id == R.id.action_edit_friends) {
        Intent intent = new Intent(this, EditFriendsActivity.class);
        startActivity(intent);
    }
    return super.onOptionsItemSelected(item);
}

@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    // When the given tab is selected, switch to the corresponding page in
    // the ViewPager.
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}

@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
}

This is my LogCat:

08-16 11:42:26.933: D/dalvikvm(1232): Not late-enabling CheckJNI (already on)
08-16 11:42:27.243: E/Trace(1232): error opening trace file: No such file or directory (2)
08-16 11:42:27.663: I/MainActivity(1232): Satyam
08-16 11:42:27.824: D/dalvikvm(1232): GC_CONCURRENT freed 239K, 6% free 4333K/4600K, paused 4ms+26ms, total 142ms
08-16 11:42:28.014: D/libEGL(1232): loaded /system/lib/egl/libEGL_emulation.so
08-16 11:42:28.024: D/(1232): HostConnection::get() New Host Connection established 0x556f6690, tid 1232
08-16 11:42:28.034: D/libEGL(1232): loaded /system/lib/egl/libGLESv1_CM_emulation.so
08-16 11:42:28.034: D/libEGL(1232): loaded /system/lib/egl/libGLESv2_emulation.so
08-16 11:42:28.114: W/EGL_emulation(1232): eglSurfaceAttrib not implemented
08-16 11:42:28.156: D/OpenGLRenderer(1232): Enabling debug mode 0
08-16 11:45:03.034: D/dalvikvm(1232): Debugger has detached; object registry had 1 entries
08-16 11:46:22.263: E/Trace(1280): error opening trace file: No such file or directory (2)
08-16 11:46:22.303: D/AndroidRuntime(1280): Shutting down VM
08-16 11:46:22.303: W/dalvikvm(1280): threadid=1: thread exiting with uncaught exception (group=0x2bd39930)
08-16 11:46:22.313: E/AndroidRuntime(1280): FATAL EXCEPTION: main
08-16 11:46:22.313: E/AndroidRuntime(1280): java.lang.RuntimeException: Unable to instantiate application com.satty002.swag.SwagApplication: java.lang.NullPointerException
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.LoadedApk.makeApplication(LoadedApk.java:504)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4364)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.ActivityThread.access$1300(ActivityThread.java:141)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1294)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.os.Looper.loop(Looper.java:137)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.ActivityThread.main(ActivityThread.java:5039)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at java.lang.reflect.Method.invokeNative(Native Method)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at java.lang.reflect.Method.invoke(Method.java:511)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at dalvik.system.NativeStart.main(Native Method)
08-16 11:46:22.313: E/AndroidRuntime(1280): Caused by: java.lang.NullPointerException
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java:379)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.LoadedApk.getClassLoader(LoadedApk.java:322)
08-16 11:46:22.313: E/AndroidRuntime(1280):     at android.app.LoadedApk.makeApplication(LoadedApk.java:496)
08-16 11:46:22.313: E/AndroidRuntime(1280):     ... 11 more
08-16 11:46:30.234: E/Trace(1316): error opening trace file: No such file or directory (2)
08-16 11:46:30.984: I/MainActivity(1316): Satyam
08-16 11:46:31.114: D/dalvikvm(1316): GC_CONCURRENT freed 277K, 7% free 4295K/4596K, paused 4ms+6ms, total 99ms
08-16 11:46:31.264: D/libEGL(1316): loaded /system/lib/egl/libEGL_emulation.so
08-16 11:46:31.264: D/(1316): HostConnection::get() New Host Connection established 0x55712580, tid 1316
08-16 11:46:31.286: D/libEGL(1316): loaded /system/lib/egl/libGLESv1_CM_emulation.so  
08-16 11:46:31.286: D/libEGL(1316): loaded /system/lib/egl/libGLESv2_emulation.so
08-16 11:46:31.344: W/EGL_emulation(1316): eglSurfaceAttrib not implemented
08-16 11:46:31.373: D/OpenGLRenderer(1316): Enabling debug mode 0
08-16 11:46:33.154: W/EGL_emulation(1316): eglSurfaceAttrib not implemented
08-16 11:46:33.464: D/dalvikvm(1316): GC_CONCURRENT freed 210K, 6% free 4489K/4728K, paused 4ms+3ms, total 96ms
08-16 11:46:35.713: W/EGL_emulation(1316): eglSurfaceAttrib not implemented
08-16 11:46:36.364: D/AndroidRuntime(1316): Shutting down VM
08-16 11:46:36.364: W/dalvikvm(1316): threadid=1: thread exiting with uncaught exception (group=0x2bd39930)
08-16 11:46:36.384: E/AndroidRuntime(1316): FATAL EXCEPTION: main
08-16 11:46:36.384: E/AndroidRuntime(1316): java.lang.NullPointerException
08-16 11:46:36.384: E/AndroidRuntime(1316):     at com.satty002.swag.EditFriendsActivity$1.done(EditFriendsActivity.java:49)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at com.parse.FindCallback.internalDone(FindCallback.java:45)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at com.parse.FindCallback.internalDone(FindCallback.java:31)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at com.parse.Parse$5$1.run(Parse.java:891)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at android.os.Handler.handleCallback(Handler.java:725)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at android.os.Handler.dispatchMessage(Handler.java:92)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at android.os.Looper.loop(Looper.java:137)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at android.app.ActivityThread.main(ActivityThread.java:5039)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at java.lang.reflect.Method.invokeNative(Native Method)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at java.lang.reflect.Method.invoke(Method.java:511)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-16 11:46:36.384: E/AndroidRuntime(1316):     at dalvik.system.NativeStart.main(Native Method)
08-16 11:46:38.394: E/Trace(1343): error opening trace file: No such file or directory (2)
08-16 11:46:39.094: I/MainActivity(1343): Satyam
08-16 11:46:39.184: D/dalvikvm(1343): GC_CONCURRENT freed 267K, 7% free 4289K/4584K, paused 4ms+6ms, total 72ms
08-16 11:46:39.344: D/libEGL(1343): loaded /system/lib/egl/libEGL_emulation.so
08-16 11:46:39.344: D/(1343): HostConnection::get() New Host Connection established 0x556cee40, tid 1343
08-16 11:46:39.364: D/libEGL(1343): loaded /system/lib/egl/libGLESv1_CM_emulation.so
08-16 11:46:39.364: D/libEGL(1343): loaded /system/lib/egl/libGLESv2_emulation.so
08-16 11:46:39.424: W/EGL_emulation(1343): eglSurfaceAttrib not implemented
08-16 11:46:39.445: D/OpenGLRenderer(1343): Enabling debug mode 0
08-16 11:46:41.484: D/dalvikvm(1343): GC_CONCURRENT freed 241K, 6% free 4436K/4704K, paused 4ms+2ms, total 28ms

The first stacktrace is a problem instantiating your `SwagApplication` and not anything to do with the activities. It's just temporary issue when updating an app - see http://stackoverflow.com/questions/10150899/runtimeexception-unable-to-instantiate-application. The NPE 14 seconds later is in your `done()` on row 49. Something is null there. Debug to find out. — laalto, Aug 16 '14 at 12:19

score 0 · Accepted Answer · answered Aug 16 '14 at 12:23

0

mUsers is never initialized. Thus, users is also null and users.size() is likely causing the NullPointerException in done(). Check that mUsers or users isn't null there.

answered Aug 16 '14 at 12:23

cygery

2,309
3
18
25

Make sure that `mUsers` or `users` isn't `null`. You'll probably want to create the `List` for `mUsers` somewhere, e.g., in `onCreate` via `mUsers = new ArrayList();`. – cygery Aug 17 '14 at 08:52
That problem is solved but I can't see any users now ! – Satyam Aggarwal Aug 17 '14 at 09:05
Yes, you have to add them to your `List`. – cygery Aug 17 '14 at 09:07

When I opened Edit friends from menu, Application stopped

1 Answers1