android - Out of memory Exception

Question

I develop one android app for book read. The Book pages and audios are download from Amazon Bucket. After downloading it stores on SD Card.

I place to two button for next and previous pages. When I display pages It gives me Out of Memory Exception.

11-03 10:59:39.199: E/AndroidRuntime(13566): FATAL EXCEPTION: main
11-03 10:59:39.199: E/AndroidRuntime(13566): java.lang.OutOfMemoryError
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:493)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at  android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:299)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:324)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.graphics.drawable.Drawable.createFromPath(Drawable.java:880)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at org.Infoware.childrenbible.GeneralHelper.setImgfromSDCard(GeneralHelper.java:608)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at org.Infoware.childrenbible.CoverPageActivity.onCreate(CoverPageActivity.java:205)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.Activity.performCreate(Activity.java:4465)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.ActivityThread.access$600(ActivityThread.java:123)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.os.Looper.loop(Looper.java:137)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at android.app.ActivityThread.main(ActivityThread.java:4424)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at java.lang.reflect.Method.invokeNative(Native Method)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at  java.lang.reflect.Method.invoke(Method.java:511)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-03 10:59:39.199: E/AndroidRuntime(13566):    at dalvik.system.NativeStart.main(Native Method)

Here It my Java Code:

public class PageReadActivity extends Activity 
{
    Bitmap bitmap;

@Override
protected void onCreate(Bundle savedInstanceState) 
{
        super.onCreate(savedInstanceState);
    try 
    {
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.pageread_layout);
     } 
    catch (Exception ex) 
    {
        ex.printStackTrace();
        Log.d(TAG, "Error in onCreate");
    }
}

  @Override
  protected void onStart() {
    // TODO Auto-generated method stub
    super.onStart();
    displayPage(product_code, page_Index);

      btnNext.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                          page_Index = page_Index + 1;
                 displayPage(product_code, page_Index);

            }
        });

       btnPrevious.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
             page_Index = page_Index - 1;
    displayPage(product_code, page_Index);

            }
        });

   }

      private void displayPage(String product_code, int ind) 
{
    try 
    {
        String imageName = product_code + ind + ".jpg";

        String imgFilePath = objHelper.getFullFilePath(imageName);

        File imageFile = new File(imgFilePath);

        imgViewPage = new ImageView(myContext);

        if(imageFile.exists())
        {   

            bitmap = objHelper.decodeSampledBitmapFromResource(imageName,objHelper.screenWidth,objHelper.screenHeight);             

            imgViewPage.setImageBitmap(bitmap);
            bitmap = null;

            String audioName = product_code+"_audio" + ind + ".mp3";
            String audioFilePath = objHelper.getFullFilePath(audioName);

            File audioFile = new File(audioFilePath);

            if(audioFile.exists())
            {   
                progressBarWaiting.setVisibility(View.INVISIBLE);
                stopAudio();
                playAudio(ind);
            }

        }
        else
        {
            System.out.println("Image not exists.....");
        }           
    } 
    catch (Exception ex) 
    {
        ex.printStackTrace();
        Log.e(TAG, "ERROR in displayPage");
    }
}

    @Override
protected void onDestroy() 
{
    super.onDestroy();
    objHelper.unbindDrawables(findViewById(R.id.pageReadLayout));
    System.gc();
}

    public void unbindDrawables(View view) 
{
    if(view.getBackground() != null)
    {
        view.getBackground().setCallback(null);
    }

    if(view instanceof ViewGroup && !(view instanceof AdapterView))
    {
        for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) 
        {
            unbindDrawables(((ViewGroup) view).getChildAt(i));
        }

        ((ViewGroup) view).removeAllViews();
    }
}

    public Bitmap decodeSampledBitmapFromResource(String fileName,int reqWidth, int reqHeight) 
{

    String imagePath = getFullFilePath(fileName);

    @SuppressWarnings("unused")
    File imgFile = new File(imagePath);

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(imagePath,options);

    // Calculate inSampleSize
    options.inSampleSize = 1;

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;

    return BitmapFactory.decodeFile(imagePath,options);
}
   }

Answer 1

Bitmap converts the original size of the image x 4. So it occupies more heap which is specified to your app by android.

Use this when your Bitmap is no longer needed

bitmap.recycle();
bitmap = null;

Answer 2

My guess is Bitmaps are not handled properly and that is creating a OutofMemoryException. Bitmaps should be recycled when not in use. Take a look here.. Also have a look at how to find memory leaks here using MAT Analyzer .