UpdateAppWidget Null Pointer Exception

Question

Following is the static method for updating the appwidget:

    public static void updateAppWidget(Context context, int id, WALL_POST_DETAILS post){
    try{
        System.out.println("In updateAppWidget==>"+id);
        AppWidgetManager mngr=AppWidgetManager.getInstance(context);

        String diff=diff(post.created_time.trim());

        RemoteViews views=new RemoteViews(context.getPackageName(),R.layout.widget_layout);         
        PendingIntent pending=PendingIntent.getActivity(context, 0, new Intent(context,ShareDialogActivity.class), 0);
        views.setOnClickPendingIntent(R.id.TextView01, pending);
        views.setOnClickPendingIntent(R.id.Button03, pending);

        views.setTextViewText(R.id.actor_name, post.actor_name);
        views.setTextViewText(R.id.actor_message, post.message);
        views.setImageViewBitmap(R.id.actor_photo, post.image);
        views.setTextViewText(R.id.created_time, diff);
        if(post.no_of_comments>0){
            views.setViewVisibility(R.id.comments_image, View.VISIBLE);
            views.setViewVisibility(R.id.comment_word, View.VISIBLE);               
            views.setTextViewText(R.id.no_of_comments, String.valueOf(post.no_of_comments));
            views.setViewVisibility(R.id.no_of_comments, View.VISIBLE);
            System.out.println("No. of Comments==>"+post.no_of_comments);
        }else{
            views.setViewVisibility(R.id.comments_image, View.INVISIBLE);
            views.setViewVisibility(R.id.comment_word, View.INVISIBLE);
            views.setTextViewText(R.id.no_of_comments, String.valueOf(""));
            views.setViewVisibility(R.id.no_of_comments, View.INVISIBLE);
        }

        if(post.no_of_likes>0){
            views.setViewVisibility(R.id.likes_image, View.VISIBLE);
            views.setViewVisibility(R.id.likes_word, View.VISIBLE);
            views.setTextViewText(R.id.no_of_likes, String.valueOf(post.no_of_likes));
            views.setViewVisibility(R.id.no_of_likes, View.VISIBLE);
        }else{
            views.setViewVisibility(R.id.likes_image, View.INVISIBLE);
            views.setViewVisibility(R.id.likes_word, View.INVISIBLE);
            views.setTextViewText(R.id.no_of_likes, String.valueOf(""));
            views.setViewVisibility(R.id.no_of_likes, View.INVISIBLE);
        }

        Intent intent_next=new Intent(context,GetPostService.class);
        Bundle b_next=new Bundle();
        b_next.putInt(MyWidgetProvider.APP_WIDGET_ID, id);
        b_next.putInt(MyWidgetProvider.REQUEST_CODE, MyWidgetProvider.NEXT_FB_POST);
        intent_next.putExtras(b_next);          
        PendingIntent nextPostService=PendingIntent.getService(context, MyWidgetProvider.NEXT_FB_POST, intent_next, PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.next_button, nextPostService);

        Intent intent_prev=new Intent(context,GetPostService.class);
        Bundle b_prev=new Bundle();
        b_prev.putInt(MyWidgetProvider.APP_WIDGET_ID, id);
        b_prev.putInt(MyWidgetProvider.REQUEST_CODE, MyWidgetProvider.PREV_FB_POST);
        intent_prev.putExtras(b_prev);
        PendingIntent prevPostService=PendingIntent.getService(context, MyWidgetProvider.PREV_FB_POST, intent_prev, PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.prev_button, prevPostService);

        Intent intent_comment=new Intent(context,FBShowCommentsActivity.class);
        Bundle b_comment=new Bundle();
        b_comment.putInt(MyWidgetProvider.APP_WIDGET_ID, id);
        b_comment.putInt(MyWidgetProvider.REQUEST_CODE, MyWidgetProvider.SHOW_COMMENTS);
        b_comment.putString(MyWidgetProvider.POST_ID, SessionStore.restoreCurrentPostId(context));
        intent_comment.putExtras(b_comment);
        PendingIntent fbActionActivity=PendingIntent.getActivity(context, MyWidgetProvider.SHOW_COMMENTS, intent_comment, PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.comment_word, fbActionActivity);
        views.setOnClickPendingIntent(R.id.comments_image, fbActionActivity);
        views.setOnClickPendingIntent(R.id.no_of_comments, fbActionActivity);

        Intent intent_likes=new Intent(context,ShowLikeDialogActivity.class);
        Bundle b_likes=new Bundle();
        b_likes.putInt(MyWidgetProvider.APP_WIDGET_ID, id);
        b_likes.putInt(MyWidgetProvider.REQUEST_CODE, MyWidgetProvider.SHOW_LIKES);
        b_likes.putString(MyWidgetProvider.POST_ID, SessionStore.restoreCurrentPostId(context));
        intent_likes.putExtras(b_likes);
        PendingIntent fbLikesActivity=PendingIntent.getActivity(context, MyWidgetProvider.SHOW_LIKES, intent_likes, PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.likes_word, fbLikesActivity);
        views.setOnClickPendingIntent(R.id.likes_image, fbLikesActivity);
        views.setOnClickPendingIntent(R.id.no_of_likes, fbLikesActivity);

        mngr.updateAppWidget(id, views);

    }catch(Exception e){
        e.printStackTrace();
        System.out.println("Exception==>"+e.getMessage());
    }
}

AppWidget is updating successfully from GetPostService pending service. When Pending Activity is launched first time after installation, I can update the widget successfully. But If I again launch the second time, Activity is launched properly, but AppWidget is not getting update and It throws null pointer exception. I am updating the widget from UI thread (from onPostExecute() method of AsyncTask).

W/System.err( 522): at android.widget.RemoteViews$ReflectionAction.writeToPa rcel(RemoteViews.java:400) W/System.err( 522): at android.widget.RemoteViews.writeToParcel(RemoteViews. java:1012) W/System.err( 522): at com.android.internal.appwidget.IAppWidgetService$Stub $Proxy.updateAppWidgetIds(IAppWidgetService.java:374) W/System.err( 522): at android.appwidget.AppWidgetManager.updateAppWidget(Ap pWidgetManager.java:246) W/System.err( 522): at android.appwidget.AppWidgetManager.updateAppWidget(Ap pWidgetManager.java:265) W/System.err( 522): at com.mobisys.android.app_widget.MyWidgetProvider.updat eAppWidget(MyWidgetProvider.java:185) W/System.err( 522): at com.mobisys.android.app_widget.MyWidgetProvider.onRec eive(MyWidgetProvider.java:71) W/System.err( 522): at android.app.ActivityThread.handleReceiver(ActivityThr ead.java:1769) W/System.err( 522): at android.app.ActivityThread.access$2400(ActivityThread .java:117) W/System.err( 522): at android.app.ActivityThread$H.handleMessage(ActivityTh read.java:978) W/System.err( 522): at android.os.Handler.dispatchMessage(Handler.java:99) W/System.err( 522): at android.os.Looper.loop(Looper.java:123) W/System.err( 522): at android.app.ActivityThread.main(ActivityThread.java:3 647) W/System.err( 522): at java.lang.reflect.Method.invokeNative(Native Method) W/System.err( 522): at java.lang.reflect.Method.invoke(Method.java:507) W/System.err( 522): at com.android.internal.os.ZygoteInit$MethodAndArgsCalle r.run(ZygoteInit.java:839) W/System.err( 522): at com.android.internal.os.ZygoteInit.main(ZygoteInit.ja va:597) W/System.err( 522): at dalvik.system.NativeStart.main(Native Method)

I am calling the updateAppWidget static method in following way from Pending Activity:

MyWidgetProvider.updateAppWidget(context, mAppWidgetId, post); //context is pending Activity's instance

What can be the issue?

Thanks in advance.

Answer 1

I had exactly the same issue and stack trace. The reason was a null Bitmap that I passed in setImageViewBitmap. It is probably too late for answer but I think You should double check this line:

views.setImageViewBitmap(R.id.actor_photo, post.image);

If Im right post.image will be null - You should remove this line or provide a non null Bitmap.

Regards