)import java.util.concurrent.CompletableFuture; import java.util.concurrent.ExecutionException; class TestCompletableFuture { public static void main(String[] args) throws Exception { CompletableFuture future = CompletableFuture.runAsync(()->{//调用没有返回值的方法 System.out.println(Thread.currentThread().getName()+"启动"); }); Object o = future.get(); System.out.println("test"+o); //结果为空 CompletableFuture<Integer> future1 = CompletableFuture.supplyAsync(()->{//调用有返回值的方法 System.out.println(Thread.currentThread().getName()+"启动"); // int x = 1/0; return 100; }); future1.whenComplete((u,t)->{//u 是返回值,t是异常的getMessage() System.out.println(u); System.out.println(t); }).get();//调用get()方法可以获取到返回值,或抛出异常 } }