title: Android image download from server?
body: <pre><code>my logcat---------::
  
  
  09-07 19:55:51.623: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:55:51.634: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:55:52.033: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 1896 objects / 518112 bytes in 97ms
  09-07 19:55:52.364: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:55:53.254: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 822 objects / 539696 bytes in 67ms
  09-07 19:56:01.514: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805085124_wtpa.logo.png
  09-07 19:56:01.584: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805084621_wtpa.logo.png
  09-07 19:56:01.643: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805025050_chuckie liv.ashx.jpg
  09-07 19:56:01.684: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805024007_space vegas.ashx.jpg
  09-07 19:56:01.914: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:01.953: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:02.714: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:02.754: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805023407_blush vegas.ashx.jpg
  09-07 19:56:02.834: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805022856_Savoy vegas.ashx.jpg
  09-07 19:56:02.944: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 1058 objects / 490016 bytes in 80ms
  09-07 19:56:02.944: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:02.944: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:03.894: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:03.923: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110808101519_DSC0028-Ti.jpg
  09-07 19:56:04.104: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110729152914_wtpa.logo.png
  09-07 19:56:04.604: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:04.634: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:05.004: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 966 objects / 515008 bytes in 80ms
  09-07 19:56:05.404: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:05.434: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:05.464: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  09-07 19:56:06.194: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
  </code></pre>
  
  <p>my code is :: </p>
  
  <pre><code>import java.io.BufferedInputStream;
  import java.io.BufferedOutputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.HttpURLConnection;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.net.URL;
  import java.net.URLDecoder;
  import java.net.URLEncoder;
  import java.util.Collections;
  import java.util.Map;
  import java.util.Stack;
  import java.util.WeakHashMap;
  
  import org.apache.http.HttpEntity;
  import org.apache.http.HttpResponse;
  import org.apache.http.client.HttpClient;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.entity.BufferedHttpEntity;
  import org.apache.http.impl.client.DefaultHttpClient;
  
  import android.app.Activity;
  import android.content.Context;
  import android.graphics.Bitmap;
  import android.graphics.BitmapFactory;
  import android.util.EventLogTags.Description;
  import android.view.View;
  import android.widget.ImageView;
  import android.widget.ProgressBar;
  
  public class ImageLoader {
  
      MemoryCache memoryCache = new MemoryCache();
      FileCache fileCache;
      private Map&lt;ImageView, String&gt; imageViews = Collections
              .synchronizedMap(new WeakHashMap&lt;ImageView, String&gt;());
      private ProgressBar indicator;
  
      public ImageLoader(Context context) {
  
          photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
          fileCache = new FileCache(context);
      }
  
      public void DisplayImage(String url, Context activity, ImageView imageView,
              ProgressBar pbar) {
  
          imageViews.put(imageView, url);
          Bitmap bitmap = memoryCache.get(url);
  
          if (bitmap != null) {
              this.indicator = pbar;
              indicator.setVisibility(View.INVISIBLE);
              imageView.setImageBitmap(bitmap);
          } else {
              this.indicator = pbar;
              indicator.setVisibility(View.INVISIBLE);
              queuePhoto(url, activity, imageView);
              imageView.setImageBitmap(null);
          }
      }
  
      private void queuePhoto(String url, Context activity, 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();
      }
  
      private Bitmap getBitmap(String url) {
          File f = fileCache.getFile(url);
  
          // from SD cache
          Bitmap b = decodeFile(f);
          if (b != null)
              return b;
  
          // from web
          try {
  
              HttpGet httpRequest = null;
  
              try {
  
  
                  int pos = url.lastIndexOf('/') + 1;
                  URI uri = new URI(url.substring(0, pos)
                          + URLEncoder.encode(url.substring(pos), "UTF-8"));
                 //URL imgUrl = new URL(decodeUrl);
                  httpRequest = new HttpGet(uri);
              } catch (URISyntaxException e) {
                  System.out.println("Error ::" + e.toString());
                  e.printStackTrace();
              }
  
              HttpClient httpclient = new DefaultHttpClient();
              HttpResponse response = (HttpResponse) httpclient
                      .execute(httpRequest);
  
              HttpEntity entity = response.getEntity();
              BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity);
              InputStream instream = bufHttpEntity.getContent();
              Bitmap bm = BitmapFactory.decodeStream(instream);
  
              /*
               * Bitmap bitmap = null; URL imageUrl = new URL(url);
               * HttpURLConnection conn = (HttpURLConnection) imageUrl
               * .openConnection(); conn.connect(); conn.getDoOutput();
               * 
               * 
               * 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;
               */
              return bm;
          } catch (Exception ex) {
              ex.printStackTrace();
              return null;
          }
      }
  
      private Bitmap gonextUrl(String url) {
          Bitmap bm = null;
          try {
  
              URL imgUrl = new URL(url);
              HttpGet httpRequest = new HttpGet(imgUrl.toURI());
  
              HttpClient httpclient = new DefaultHttpClient();
              HttpResponse response = (HttpResponse) httpclient
                      .execute(httpRequest);
  
              HttpEntity entity = response.getEntity();
              BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity);
              InputStream instream = bufHttpEntity.getContent();
              bm = BitmapFactory.decodeStream(instream);
  
              return bm;
          } catch (Exception e) {
              e.printStackTrace();
          }
          return bm;
      }
  
      // 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 = 70;
              int width_tmp = o.outWidth, height_tmp = o.outHeight;
              int scale = 1;
              while (true) {
                  if (width_tmp / 2 &lt; REQUIRED_SIZE
                          || height_tmp / 2 &lt; REQUIRED_SIZE)
                      break;
                  width_tmp /= 2;
                  height_tmp /= 2;
                  scale *= 2;
              }
  
              BitmapFactory.Options o2 = new BitmapFactory.Options();
              o2.inSampleSize = scale;
              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) {
  
                      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, indicator);
                              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;
  
          // private ProgressBar indicator1;
  
          public BitmapDisplayer(Bitmap b, ImageView i, ProgressBar indicator) {
              this.bitmap = b;
              this.imageView = i;
              // this.indicator1 = indicator;
          }
  
          public void run() {
              if (bitmap != null) {
                  // indicator1.setVisibility(View.INVISIBLE);
                  imageView.setImageBitmap(bitmap);
              } else
                  imageView.setImageBitmap(null);
          }
      }
  
      public void clearCache() {
          memoryCache.clear();
          fileCache.clear();
      }
  
  }
  </code></pre>