public void listenChanges() {
 context.getContentResolver().registerContentObserver(CONTENT_URI,true,new MyContentObserver());
}
public class MyContentObserver extends android.database.ContentObserver {
 public MyContentObserver() {
  super(null);
 }
 @Override
 public void onChange(boolean selfChange) {
  super.onChange(selfChange);
  //Do all you need here
 }
}