title: How to solve outofmemory error during listview scrolling?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/5082703/android-out-of-memory-error-with-lazy-load-images">Android Out of Memory error with Lazy Load images</a><br>
    <a href="https://stackoverflow.com/questions/13376899/outofmemory-error-during-scrolling-the-listview-fastly">Outofmemory error during scrolling the listview fastly</a>  </p>
  </blockquote>
  
  
  
  <p>I am using listview to display the images,names from the facebook api.I can able to display images correctly.My problem is when I scroll the list fastly I am getting </p>
  
  <pre><code>    11-15 18:41:29.841: E/dalvikvm-heap(32303): 786432-byte external allocation too large for this process.
  11-15 18:41:29.887: I/dalvikvm-heap(32303): Clamp target GC heap from 32.095MB to 32.000MB
  11-15 18:41:29.887: E/GraphicsJNI(32303): VM won't let us allocate 786432 bytes
  11-15 18:41:29.887: D/dalvikvm(32303): GC_FOR_MALLOC freed 0K, 51% free 4380K/8903K, external 23826K/25864K, paused 31ms
  11-15 18:41:29.887: D/skia(32303): --- decoder-&gt;decode returned false
  11-15 18:41:29.887: W/dalvikvm(32303): threadid=18: thread exiting with uncaught exception (group=0x40018560)
  11-15 18:41:29.887: E/AndroidRuntime(32303): FATAL EXCEPTION: Thread-29
  11-15 18:41:29.887: E/AndroidRuntime(32303): java.lang.OutOfMemoryError: bitmap size exceeds VM budget
  11-15 18:41:29.887: E/AndroidRuntime(32303):    at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
  11-15 18:41:29.887: E/AndroidRuntime(32303):    at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:470)
  11-15 18:41:29.887: E/AndroidRuntime(32303):    at com.beerbro.utils.ImageLoader.decodeFile(ImageLoader.java:156)
  11-15 18:41:29.887: E/AndroidRuntime(32303):    at com.beerbro.utils.ImageLoader.getBitmap(ImageLoader.java:99)
  11-15 18:41:29.887: E/AndroidRuntime(32303):    at com.beerbro.utils.ImageLoader$PhotosLoader.run(ImageLoader.java:214)
  </code></pre>
  
  <p>But when I scroll this listview slowly I am not getting any errors.</p>
  
  <p>Here is my Adapter class where I called Imageloader class displayImage method to convert my url into bitmap and set it to imageview.</p>
  
  <pre><code>    public class MySimpleArrayAdapter extends ArrayAdapter&lt;String&gt; {
      private Activity context;
      ArrayList&lt;String&gt; namear,msgar,idar,profimage,postimage,commentsnum,objectid,urlString;
  
    ImageLoader imageLoader;
    Bitmap[] bitdata;
  
  
    public MySimpleArrayAdapter(Activity c,int i,ArrayList&lt;String&gt; postpic, ArrayList&lt;String&gt; names,ArrayList&lt;String&gt; msg,ArrayList&lt;String&gt; id,ArrayList&lt;String&gt; proimg,Bitmap[] bit,ArrayList&lt;String&gt; comment,ArrayList&lt;String&gt; objid,ArrayList&lt;String&gt; web) {
  
        super(c, i, names);
      Log.e("adapter","adap");
      this.context = c;
      this.namear = names;
      this.msgar = msg;
      this.idar = id;
      this.profimage=proimg;
      this.postimage=postpic;
      this.bitdata=bit;
      this.commentsnum=comment;
      this.objectid=objid;
      this.urlString=web;
     this.imageLoader = new ImageLoader(context);
    }
  
  
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        View rowView=convertView ;
        LayoutInflater inflator =   getLayoutInflater();
        rowView = inflator.inflate(R.layout.walldata, null);
  
        TextView name1 = (TextView) rowView.findViewById(R.id.name);
        TextView message1 = (TextView) rowView.findViewById(R.id.msg);
        ImageView profimg= (ImageView) rowView.findViewById(R.id.profile_pic);
        ImageView postimg= (ImageView) rowView.findViewById(R.id.picpost);
    TextView comments = (TextView) rowView.findViewById(R.id.comment);
  
       Log.e("user",idar.get(position));
  
  
      Log.e("adapter","adap");
     name1.setText(namear.get(position));
      if(msgar.get(position)!=""){
      message1.setText(msgar.get(position));
  
      }
      else
      {
          message1.setVisibility(View.GONE);
      }
      if(!postimage.get(position).equals(""))
      {try{
           imageLoader.DisplayImage(postimage.get(position).replace(" ", "%20"), postimg) ;
  
      }
      catch(Exception e){
          e.printStackTrace();
      }
      }
      else
      {
          postimg.setVisibility(View.GONE);
      }
      try{
        imageLoader.DisplayImage(profimage.get(position).replace(" ", "%20"), profimg) ;
  
      }
      catch(Exception e){
         e.printStackTrace();
      }
  
         comments.setText(commentsnum.get(position)+"\t"+"Comments");
         comments.setOnClickListener(new OnClickListener() {
  
  
          public void onClick(View v) {
              Intent myintent=new Intent(Wall.this,Comments.class);
              myintent.putExtra("name", namear.get(position));
              myintent.putExtra("profimg", profimage.get(position));
              myintent.putExtra("message", msgar.get(position));
              myintent.putExtra("postpic", postimage.get(position));
              myintent.putExtra("objectid", objectid.get(position));
              myintent.putExtra("commentsnum",commentsnum.get(position));
              myintent.putExtra("webservice", urlString.get(position));
              startActivity(myintent);
  
          }
      });
  
      return rowView;
    }
  </code></pre>
  
  <p>Here is my Imageloader class </p>
  
  <pre><code> public class ImageLoader {
  
      MemoryCache memoryCache=new MemoryCache();
      FileCache fileCache;
      private Map&lt;ImageView, String&gt; imageViews=Collections.synchronizedMap(new WeakHashMap&lt;ImageView, String&gt;());
  
      public ImageLoader(Context context){
  
          photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);
  
          fileCache=new FileCache(context);
      }
  
      public void DisplayImage(String url,ImageView imageView)
      {
          imageViews.put(imageView, url);
  
  
          Bitmap bitmap=memoryCache.get(url);
  
          if(bitmap!=null)
          {
              imageView.setBackgroundDrawable(new BitmapDrawable(bitmap));
  
              System.gc();
          }
          else
          {
              queuePhoto(url, imageView);
  
          }    
      }
  
      private Bitmap createScaledBitmap(Bitmap bitmap, int i, int j, int k) {
          return null;
      }
  
      private void queuePhoto(String url, ImageView imageView)
      {
          //This ImageView may be used for other images before. So there may be some old tasks in the queue. We need to discard them. 
          photosQueue.Clean(imageView);
          PhotoToLoad p=new PhotoToLoad(url, imageView);
          synchronized(photosQueue.photosToLoad){
              photosQueue.photosToLoad.push(p);
              photosQueue.photosToLoad.notifyAll();
          }
  
          //start thread if it's not started yet
          if(photoLoaderThread.getState()==Thread.State.NEW)
              photoLoaderThread.start();
      }
  
     public Bitmap getBitmap(String url) 
      {
          File f=fileCache.getFile(url);
  
          //from SD cache
          Bitmap b = decodeFile(f);
          if(b!=null)
              return b;
  
          //from web
          try {
              Bitmap bitmap=null;
              URL imageUrl = new URL(url);
              HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
              conn.setConnectTimeout(30000);
              conn.setReadTimeout(30000);
              InputStream is=conn.getInputStream();
              OutputStream os = new FileOutputStream(f);
              Utils.CopyStream(is, os);
              os.close();
              bitmap = decodeFile(f);
              return bitmap;
          } catch (Exception ex){
             ex.printStackTrace();
             return null;
          }
      }//Lalit
  
      //decodes image and scales it to reduce memory consumption
      private Bitmap decodeFile(File f){
          try {
              //decode image size
              BitmapFactory.Options o = new BitmapFactory.Options();
              o.inJustDecodeBounds = true;
              BitmapFactory.decodeStream(new FileInputStream(f),null,o);
  
  
              //Find the correct scale value. It should be the power of 2.
  
              final int REQUIRED_SIZE=Wall.width;
              final int REQUIRED_SIZE1=Wall.height;
  
              int width_tmp=o.outWidth, height_tmp=o.outHeight;
              int scale=1;
  
              while(true){
                  if((width_tmp/2&lt;REQUIRED_SIZE)&amp;&amp;(height_tmp/2&lt;REQUIRED_SIZE1))
                      break;
                  width_tmp/=2;
                  height_tmp/=2;
                  scale*=2;
              }
  
              //decode with inSampleSize
              BitmapFactory.Options o2 = new BitmapFactory.Options();
              o2.inJustDecodeBounds = true;
              BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
              o2.inSampleSize=scale;
              o2.inJustDecodeBounds = false;
  
              return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
  
  
          } catch (FileNotFoundException e) {}
          return null;
      }
  
      //Task for the queue
      private class PhotoToLoad
      {
          public String url;
          public ImageView imageView;
          public PhotoToLoad(String u, ImageView i){
              url=u; 
              imageView=i;
          }
      }
  
      PhotosQueue photosQueue=new PhotosQueue();
  
      public void stopThread()
      {
          photoLoaderThread.interrupt();
      }
  
      //stores list of photos to download
      class PhotosQueue
      {
          private Stack&lt;PhotoToLoad&gt; photosToLoad=new Stack&lt;PhotoToLoad&gt;();
  
          //removes all instances of this ImageView
          public void Clean(ImageView image)
          {
              for(int j=0 ;j&lt;photosToLoad.size();){
                  if(photosToLoad.get(j).imageView==image)
                      photosToLoad.remove(j);
                  else
                      ++j;
              }
          }
      }
  
      class PhotosLoader extends Thread {
          public void run() {
              try {
                  while(true)
                  {
                      //thread waits until there are any images to load in the queue
                      if(photosQueue.photosToLoad.size()==0)
                          synchronized(photosQueue.photosToLoad){
                              photosQueue.photosToLoad.wait();
                          }
                      if(photosQueue.photosToLoad.size()!=0)
                      {
                          PhotoToLoad photoToLoad;
                          synchronized(photosQueue.photosToLoad){
                              photoToLoad=photosQueue.photosToLoad.pop();
                          }
                          Bitmap bmp=getBitmap(photoToLoad.url);
                          memoryCache.put(photoToLoad.url, bmp);
                          String tag=imageViews.get(photoToLoad.imageView);
                          if(tag!=null &amp;&amp; tag.equals(photoToLoad.url)){
                              BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView);
                              Activity a=(Activity)photoToLoad.imageView.getContext();
                              a.runOnUiThread(bd);
                          }
                      }
                      if(Thread.interrupted())
                          break;
                  }
              } catch (InterruptedException e) {
                  //allow thread to exit
              }
          }
      }
  
      PhotosLoader photoLoaderThread=new PhotosLoader();
  
      //Used to display bitmap in the UI thread
      class BitmapDisplayer implements Runnable
      {
          Bitmap bitmap;
          ImageView imageView;
          public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;}
          public void run()
          {
              if(bitmap!=null)
                  imageView.setBackgroundDrawable(new BitmapDrawable(bitmap));
  
          }
      }
  
      public void clearCache() {
          memoryCache.clear();
          fileCache.clear();
      }
      public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels,int width,int height) {
  
          Bitmap output = Bitmap.createBitmap(width,height, Config.ARGB_8888);
          Canvas canvas = new Canvas(output);
  
          final int color = 0xff424242;
          final Paint paint = new Paint();
          final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
          final RectF rectF = new RectF(rect);
          final float roundPx = pixels;
  
          paint.setAntiAlias(true);
          canvas.drawARGB(0, 0, 0, 0);
          paint.setColor(color);
          canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
  
          paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
          canvas.drawBitmap(bitmap, rect, rect, paint);
  
          return output;
      }
  </code></pre>
  
  <p>I am scaling the images upto my device screen size i.e 480*854,you can find this in imageloader class,I also mention here for easy understanding</p>
  
  <pre><code>     final int REQUIRED_SIZE=Wall.width;
              final int REQUIRED_SIZE1=Wall.height;
  
              int width_tmp=o.outWidth, height_tmp=o.outHeight;
              int scale=1;
  
              while(true){
                  if((width_tmp/2&lt;REQUIRED_SIZE)&amp;&amp;(height_tmp/2&lt;REQUIRED_SIZE1))
                      break;
                  width_tmp/=2;
                  height_tmp/=2;
                  scale*=2;
              }
      }
  </code></pre>
  
  <p>By looking at the error I can understand that memory is not sufficient for loading bitmap,I dont know how can I deallocate memory at runtime.
   please help me I referred to many of the links in stackoverflow and others but couldnt fix this issue.</p>