public class MyCallable implements Callable<String> {
    private String username;
    private long sleepValue;
    public MyCallable(String username, long sleepValue) {
        this.username = username;
        this.sleepValue = sleepValue;
    }

    @Override
    public String call() throws Exception {
        //当
        System.out.println(username);
        Thread.sleep(sleepValue);
        // if ("userName3".equals(username)){
        //    throw new Exception("自己抛出异常了");
        // }
        return "return: "+ username;   
      
    }}

@Test
public void testMyCallable() throws InterruptedException {
    try {
        List<MyCallable> list = new ArrayList<>();
        for (int i=1; i<=5; i++){
            MyCallable myCallable = new MyCallable("userName"+i, i*1000);
            list.add(myCallable);
        }

        //手动线程数  最大线程  当多少时后面线程进行排队
        ThreadPoolExecutor executor = new ThreadPoolExecutor(5,10,5, TimeUnit.SECONDS, new LinkedBlockingDeque<Runnable>());
        
        //自动处理线程
        ExecutorService executor = Executors.newCachedThreadPool();

        CompletionService completionService = new ExecutorCompletionService(executor);

        for (int i=0; i<5; i++){
            completionService.submit(list.get(i));
        }

        //处理完结束
        executor.shutdown();

        //谁先完成谁出
        for (int i=0; i<5; i++){
            System.out.println("等待打印"+(i+1)+"个返回值");
            System.out.println(completionService.take().get());
        }  

        //怎么放进去怎么出
        for (int i=0; i<5; i++){
           System.out.println("一个一个等待返回结果: " + completionService.get(i).get());
        } 
    } catch (InterruptedException e) {
        e.printStackTrace();
    } catch (ExecutionException e) {
        e.printStackTrace();
    }

}



//实际开发对多线程进行封装 只负责调用  方法与实例分开
package com.util.common;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.*;

public class ThreadUtil implements Callable<Object> {
    private Object task;

    public Object getTask() {
        return task;
    }

    public void setTask(Object task) {
        this.task = task;
    }

    @Override
    public Object call() throws Exception {
        return getTask();
    }



    public static void main(String[] args) {
        try {
            List<ThreadUtil> list = new ArrayList<>();
            for (int i=1; i<=5; i++){
                ThreadUtil threadUtil = new ThreadUtil();
                //方法
                ThreadUtil p= new ThreadUtil();
                threadUtil.setTask(p.getStr(i));

                list.add(threadUtil);
            }

            //手动
            ThreadPoolExecutor executor = new ThreadPoolExecutor(5,10,5, TimeUnit.SECONDS, new LinkedBlockingDeque<Runnable>());

            //内置
            //ExecutorService executorService = Executors.newCachedThreadPool();
            CompletionService completionService = new ExecutorCompletionService(executor);

            //运行任务
            for(int i=0;i<list.size();i++){
                completionService.submit(list.get(i));
            }
            //运行完关闭
            executor.shutdown();

            //谁先出 先取
            System.out.println("谁先出 先取");
            for(int i=0;i<list.size();i++){
                System.out.println(completionService.take().get());
            }


            System.out.println("按顺序取");
            for(int i=0;i<list.size();i++){
                System.out.println(list.get(i).getTask());
            }


        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    //模拟任务
    public int getStr(int str) {
        try{
            System.out.println("传值:"+str);
            int r=new Random().nextInt(400)+1000;
            Thread.sleep(r);

        }catch (Exception e){

        }
        return str;
    }
}