android - How to put condition on downloading image for listview? -

 public avatardownloader(context context){     //make background thread low priority. way not affect ui performance     photoloaderthread.setpriority(thread.norm_priority-1);      //find dir save cached images     if (android.os.environment.getexternalstoragestate().equals(android.os.environment.media_mounted))         cachedir=new file(android.os.environment.getexternalstoragedirectory(),"/download/myapp/avatars/");     else         cachedir=context.getcachedir();     if(!cachedir.exists())         cachedir.mkdirs();  }  final int stub_id=r.drawable.ic_launcher; public void displayimage(string url, string profilepic, activity activity, imageview imageview) {     if(cache.containskey(url))         imageview.setimagebitmap(cache.get(url));     else     {          //queuephoto(url, activity, imageview, profilepic);         imageview.setimageresource(stub_id);     }     }  private void queuephoto(string url, activity activity, imageview imageview, string profilepic) {     //this imageview may used other images before. there may old tasks in queue. need discard them.      photosqueue.clean(imageview);     system.err.println("qph"+url);     phototoload p=new phototoload(url, imageview, profilepic);     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(); } 

here put code image downloader. want put code if image not available on server ic_launcher images shows. if image available show in listview.

i suggest use universal image loader image loading/showing related task. automatically handle memory management , can set own image if image not available on server.