java - 如何询问 CompletableFuture 使用非守护线程？

Question

我写了下面的代码:

 System.out.println("Main thread:" + Thread.currentThread().getId());
 CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {
     try {
         System.out.println("Before sleep thread:" + Thread.currentThread().getId(), + " isDaemon:" + Thread.currentThread().isDaemon());
          Thread.sleep(100);
          System.out.println("After sleep");
      } catch (InterruptedException e) {
          e.printStackTrace();
      }
  });
  future.whenComplete((r, e) -> System.out.println("whenCompleted thread:" + Thread.currentThread().getId()));

这一个打印:

Main thread:1
Before sleep thread:11 isDaemon:true

并完成。

我怎样才能改变这种行为？

P.S. 我在 runAsync java doc

中没有看到任何相关内容

Answer 1

javadoc对于 runAsync() 说:

Returns a new CompletableFuture that is asynchronously completed by a task running in the ForkJoinPool.commonPool() after it runs the given action.

另一个版本的 runAsync() 您可以在其中传递 ExecutorService。

因此:当默认commonPool()不做你想做的 - 然后创建你自己的 ExecutorService。