常用之juc

// 没有返回值的异步回调 CompletableFuture.runAsync
// get方法会阻塞
CompletableFuture<Void> completableFuture=CompletableFuture.runAsync(()->{
try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"runAsync->Void");
});

System.out.println("Demo1.main 11111");
completableFuture.get();
System.out.println("Demo1.main 22222");

// 有返回值得异步回调 CompletableFuture.supplyAsync
// whenComplete 编译成功后的处理
// exceptionally 异常后的处理
// get方法会阻塞
CompletableFuture<Integer> uCompletableFuture = CompletableFuture.supplyAsync(() -> {
System.out.println(Thread.currentThread().getName() + "supplyAsync->Integer");
int i=10/0;
return 1024;
});
System.out.println("Demo1.main 11111");
Integer integer = uCompletableFuture.whenComplete((t, u) -> {
System.out.println("t=>"+t); // 正常情况下，返回结果
System.out.println("u=>"+u);
}).exceptionally((e) -> { //异常情况下的处理
System.out.println(e.getMessage());
return 233;
}).get();
System.out.println(integer);
System.out.println("Demo1.main 22222");