Java Async等待完成

Question

Ho do i get my function to wait for being done with it's async task before returning the variable?

public boolean CheckOnline(){
    OnlineAsyncTask onlinetsk = new OnlineAsyncTask();
    onlinetsk.execute();
    return Online;
} 

Answer 1

You can call get() to wait for the async task to complete and retrieve the result.

However that defeats the purpose of an async task - it's no longer asynchronous. Consider redesigning your app so that you don't need to wait for a result. Instead eg use a callback interface to notify that the async task has finished and a result is available.

Answer 2

String str_result= new OnlineAsyncTask().execute().get();

这将使其等待直到返回值