用Callable创建线程

创建线程的办法除了继承Thread类和实现Runnable接口，还有实现Callable接口。

以下代码演示使用Callable接口：

package com.cxf.multithread.collable;

import java.util.concurrent.*;

public class TestForCallable {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        MyJob thread = new MyJob();
        ExecutorService service = Executors.newFixedThreadPool(1);  // execute service,number of threads = 1
        Future<Boolean> result = service.submit(thread);  // submit to execute
        boolean r = result.get();  // get result
        service.shutdownNow();  // shut down the service
        System.out.println(r);

    }
}

class MyJob implements Callable{

    @Override
    public Boolean call() throws Exception {
        for (int i = 0; i < 5; i++) {
            System.out.println("I am running thread");
        }
        return true;
    }
}

输出结果：

I am running thread
I am running thread
I am running thread
I am running thread
I am running thread
true

用Callable创建线程时，需要

1.在call方法中写需要执行的任务，

2.创建执行服务，

3.提交线程到服务，

4.获取线程返回值，

5.关闭执行服务。