java的异步Callback任务

public class AsyncTest{
  public static HttpAsyncClient httpAsyncClient;
  public static CompletableFuture getHttpData(String url){
    CompletableFuture asyncFuture = new completableFuture();
    HttpAsyncRequestProducer producer = HttpAsyncMethods.create(new HttpPost(url));
    BasicAsyncResponseConsumer consumer = new BasicAsyncResponseConsumer();
    FutureCallback callback = new FutureCallback<>(HttpResponse){
   public void completed(HttpResponse response){
    asyncFuture.complete(response);
  }

  public void failed(Exception e){
    asyncFuture.completeExceptionally(e);
  }
  
  public void cancelled(){
    asyncFuture.cancel(true);
  }
}
  httpAsyncClient.execute(producer,consumer,callback);
  return asyncFuture;
  }
  
  public static void main(String[] args) throws Exception{
     CompletableFuture<> future = AsyncTest.getHttpData("http://www.xx.com");
     String result = future.get();
  }
}