LookupListener problem?

There are many unanswered threads to this question. The common issue is that the resultChanged(...) method is never triggered!! Here is a proper use-case scenario (note the comments, they provide tips to avoid common loopholes)

public SomeClass extends LookupListener
{
  //It is important that you hold a reference to Lookup.Result
  //so that it doesn't get garbage collected. This also applies to Lookup.Template
  private Lookup.Result result = lookup.getDefault().lookupResult(MyInterface.class);

  public SomeClass()
  {
      result.addLookupListener(this);
   
      //It is important to call this method once...otherwise           
      //resultChanged(...) method is never triggered!!
      resultchanged(new LookupEvent(result));
  } 

  public void resultChanged(LookupEvent ev)
  {
      //do your stuff here...
  }
}

If you still have problems, then check the META-INF/services folder of your implementation, there is probably a typo in the flat file. Its better to use @Service annotation to avoid such mistakes.