线程池处理Callable任务

线程池如何处理Callable任务

线程池如何处理Callable任务，并得到任务执行完后返回的结果。
使用ExecutorService的方法：
Future<T> submit(Callable<T> command)

package com.itheima.d8_threadpool;
 
import java.util.concurrent.Callable;
 
/**
    1、定义一个任务类 实现Callable接口  应该申明线程任务执行完毕后的结果的数据类型
 */
public class MyCallable implements Callable<String>{
    private int n;
    public MyCallable(int n) {
        this.n = n;
    }
 
    /**
       2、重写call方法（任务方法）
     */
    @Override
    public String call() throws Exception {
        int sum = 0;
        for (int i = 1; i <= n ; i++) {
            sum += i;
        }
        return Thread.currentThread().getName()
                + "执行 1-" + n+ "的和，结果是：" + sum;
    }
}

package com.itheima.d8_threadpool;
 
import java.util.concurrent.*;
 
/**
    目标：自定义一个线程池对象，并测试其特性。
 */
public class ThreadPoolDemo2 {
    public static void main(String[] args) throws Exception {
        // 1、创建线程池对象
        /**
         public ThreadPoolExecutor(int corePoolSize,
                                 int maximumPoolSize,
                                 long keepAliveTime,
                                 TimeUnit unit,
                                 BlockingQueue<Runnable> workQueue,
                                 ThreadFactory threadFactory,
                                 RejectedExecutionHandler handler)
         */
        ExecutorService pool = new ThreadPoolExecutor(3, 5 ,
                6, TimeUnit.SECONDS, new ArrayBlockingQueue<>(5) , Executors.defaultThreadFactory(),
               new ThreadPoolExecutor.AbortPolicy() );
 
        // 2、给任务线程池处理。
        Future<String> f1 = pool.submit(new MyCallable(100));
        Future<String> f2 = pool.submit(new MyCallable(200));
        Future<String> f3 = pool.submit(new MyCallable(300));
        Future<String> f4 = pool.submit(new MyCallable(400));
        Future<String> f5 = pool.submit(new MyCallable(500));
 
//        String rs = f1.get();
//        System.out.println(rs);
 
        System.out.println(f1.get());
        System.out.println(f2.get());
        System.out.println(f3.get());
        System.out.println(f4.get());
        System.out.println(f5.get());
    }
}