VIP31/springboot-demo/src/main/java/com/sf/javase/thread/MyThread3.java

package com.sf.javase.thread;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

public class MyThread3 implements Callable<String> {
    // 此时是call方法
    @Override
    public String call() throws Exception {
        Thread.sleep(2000);
        return "hello callable";
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        // Callable Future
        Callable<String> callable = new MyThread3();
        // 用来接收callable执行的结果
        FutureTask<String> futureTask = new FutureTask<>(callable);
        // 相当于把FutureTask作为Runnable传给Thread
        // 所以Thread执行run()方法时 执行的是FutureTask的run()方法
        // 而FutureTask的run()方法 又调用了Callable的call()方法
        // 所以最终效果是 call()才是真正的线程执行逻辑
        Thread thread = new Thread(futureTask);
        thread.start();

        // 通过get 接收结果 是一种阻塞的等待
        String result = futureTask.get();
        System.out.println(result);
    }
}