How do I avoid this busy-wait?

Question

public int getChildrenCount(int groupPosition) {
    if(children == null){
        new SalesRequest().execute(); // runs in other thread which 
                                      // initialises children with some value.
        while(children == null){
            // I'm doin this to avoid null pointer Exception.
            // So it comes out of the loop only when childern 
            // gets initialised.
        }
    }
    return children.length;
}

But I'm not satisfied with the way I'm handling this. Is there a better way to do this?

Answer 1

You could use a CountDownLatch to wait for the other thread to complete.

http://download.oracle.com/javase/1,5.0/docs/api/java/util/concurrent/CountDownLatch.html