Question

I got this IOException error while downloading images from the server and it crashes my application. This only happens once in awhile, usually no error occur while downloading. I’m not really sure what causes this and why this happened. It would be a great help if some one can explain on this issue. Thank you in advance!

Logcat

01-03 17:23:13.136: E/AndroidRuntime(12597): java.lang.RuntimeException: An error occured while executing doInBackground()
01-03 17:23:13.136: E/AndroidRuntime(12597):    at android.os.AsyncTask$3.done(AsyncTask.java:200)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.lang.Thread.run(Thread.java:1019)
01-03 17:23:13.136: E/AndroidRuntime(12597): Caused by: java.lang.NullPointerException
01-03 17:23:13.136: E/AndroidRuntime(12597):    at     com.f.bb.GalleryScreen$DownloadFile.doInBackground(GalleryScreen.java:242)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at com.f.bb.GalleryScreen$DownloadFile.doInBackground(GalleryScreen.java:1)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at android.os.AsyncTask$2.call(AsyncTask.java:185)
01-03 17:23:13.136: E/AndroidRuntime(12597):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
01-03 17:23:13.136: E/AndroidRuntime(12597):    ... 4 more
01-03 17:23:20.792: E/WindowManager(12597): Activity com.f.bb.GalleryScreen has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@405b3e78 that was originally added here
01-03 17:23:20.792: E/WindowManager(12597): android.view.WindowLeaked: Activity com.f.bb.GalleryScreen has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@405b3e78 that was originally added here
01-03 17:23:20.792: E/WindowManager(12597):     at android.view.ViewRoot.<init>(ViewRoot.java:263)
01-03 17:23:20.792: E/WindowManager(12597):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:171)
01-03 17:23:20.792: E/WindowManager(12597):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:114)
01-03 17:23:20.792: E/WindowManager(12597):     at android.view.Window$LocalWindowManager.addView(Window.java:424)
01-03 17:23:20.792: E/WindowManager(12597):     at android.app.Dialog.show(Dialog.java:241)
01-03 17:23:20.792: E/WindowManager(12597):     at com.f.bb.GalleryScreen$DownloadFile.onPreExecute(GalleryScreen.java:272)
01-03 17:23:20.792: E/WindowManager(12597):     at android.os.AsyncTask.execute(AsyncTask.java:391)
01-03 17:23:20.792: E/WindowManager(12597):     at com.f.bb.GalleryScreen$1$1.run(GalleryScreen.java:121)
01-03 17:23:20.792: E/WindowManager(12597):     at android.app.Activity.runOnUiThread(Activity.java:3717)
01-03 17:23:20.792: E/WindowManager(12597):     at com.f.bb.GalleryScreen$1.onClick(GalleryScreen.java:85)
01-03 17:23:20.792: E/WindowManager(12597):     at android.view.View.performClick(View.java:2538)
01-03 17:23:20.792: E/WindowManager(12597):     at         android.view.View$PerformClick.run(View.java:9152)
01-03 17:23:20.792: E/WindowManager(12597):     at android.os.Handler.handleCallback(Handler.java:587)
01-03 17:23:20.792: E/WindowManager(12597):     at android.os.Handler.dispatchMessage(Handler.java:92)
01-03 17:23:20.792: E/WindowManager(12597):     at     android.os.Looper.loop(Looper.java:130)
01-03 17:23:20.792: E/WindowManager(12597):     at android.app.ActivityThread.main(ActivityThread.java:3687)
01-03 17:23:20.792: E/WindowManager(12597):     at java.lang.reflect.Method.invokeNative(Native Method)
01-03 17:23:20.792: E/WindowManager(12597):     at java.lang.reflect.Method.invoke(Method.java:507)
01-03 17:23:20.792: E/WindowManager(12597):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
01-03 17:23:20.792: E/WindowManager(12597):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
01-03 17:23:20.792: E/WindowManager(12597):     at dalvik.system.NativeStart.main(Native Method)
01-03 17:27:16.148: I/Process(12597): Sending signal. PID: 12597 SIG: 9

Code (AsyncTask)

    private class DownloadFile extends AsyncTask<String, Integer, String>{
    @Override
    protected String doInBackground(String... sUrl){

        Bitmap bm;
        InputStream in;
        if(downloadFailed == false){
            if (contentId != null && contentId.length>0){
                Log.i(TAG, "contentid.length:" +contentId.length);
                for (int i=0;i<contentId.length;i++){
                    if(helper.databaseChecking(useremail, contentId[i])){
                        Constant.CONTENT_ID = contentId[i]; 
                        Log.i(TAG, "contentId:" +contentId[i]);

                        Log.i(TAG, "Email:" +useremail);
                        Log.i(TAG, "Section ID:" +ssID);

                        downloadList = new String[contentId.length];


                        try{
                            in = new java.net.URL(downloadList[i]).openStream();
                            bm = BitmapFactory.decodeStream(new PatchInputStream(in));
                            File storage = new File(Environment.getExternalStorageDirectory() + File.separator + "/testing/");
                            Log.i(TAG,"storage:" +storage);
                            Log.i(TAG,"storage:" +storage.getAbsolutePath());
                            if(!storage.exists()){
                                storage.mkdirs();
                                }
                            String FileName = "/"+Constant.CONTENT_ID+".jpg"; 
                            FileOutputStream fos = new FileOutputStream(storage + FileName);
                            bm.compress(Bitmap.CompressFormat.JPEG, 85, fos);
                            String filepath = storage + FileName;
                            File filecheck = new File (filepath);
                            long fileSize = filecheck.length();
                            fos.flush();
                            fos.close();


                            Constant.IMAGE_EXIST = 1;
                            }
                        catch(IOException e1){
                        e1.printStackTrace();
                        downloadFailed = true;
                        }

                    }

                }
            }
        }
        return null;
    }
    @Override
    protected void onPreExecute(){
        super.onPreExecute();
        pDialog.setMessage("Downloading file. Please wait...");
        pDialog.show();
    }


    protected void onPostExecute(String result){
        super.onPostExecute(result);
        pDialog.dismiss();

        alertTitle = "Information";
        alertMessage = "Sync Completed. Click 'OK' to refresh page";
        dialogBox_intent();
        Constant.SYNC_COMPLETE = true;


    }
}

Answer 1

BitmapFactory.decodeStream() can return null. See the documentation, but one case is the image that was downloaded was corrupt. You should test bm != null prior to using any methods, such as bm.compress(...)