title: How to notify another thread
body: <p>I want to know the best way how to notify another thread. For example, I have a background thread:</p>
  
  <pre><code>public void StartBackgroundThread(){
  new Thread(new Runnable() {         
          @Override
          public void run() {
              //Do something big...
              //THEN HOW TO NOTIFY MAIN THREAD?
          }
      }).start();
  }
  </code></pre>
  
  <p>When it finished it has to notify main thread? If somebody knows the best way how to do this I'll appreciate it!</p>