Java通过Callable实现多线程

忘是亡心i 2022-06-02 10:17 247阅读 0赞

import java.util.concurrent.*;
    import java.util.Date;
    import java.util.List;
    import java.util.ArrayList;
    
    public class Test implements Callable<Object>{
    
        private String taskNum;
    
        Test(String taskNum) {
            this.taskNum = taskNum;
        }
    
        public static void main(String[] args) throws ExecutionException,InterruptedException {
            System.out.println("----程序开始运行----");
            Date date1 = new Date();
            int taskSize = 5;
            // 创建一个线程池
            ExecutorService pool = Executors.newFixedThreadPool(taskSize);
            // 创建多个有返回值的任务
            List<Future> list = new ArrayList<Future>();
            for (int i = 0; i < taskSize; i++) {
                Callable c = new Test(i + " ");
                // 执行任务并获取Future对象
                Future f = pool.submit(c);
                list.add(f);
            }
            // 关闭线程池
            pool.shutdown();
            // 获取所有并发任务的运行结果
            for (Future f : list) {
                // 从Future对象上获取任务的返回值，并输出到控制台
                System.out.println(">>>" + f.get().toString());
            }
            Date date2 = new Date();
            System.out.println("----程序结束运行----，程序运行时间【" + (date2.getTime() - date1.getTime()) + "毫秒】");
        }
    
        public Object call() throws Exception {
            System.out.println(">>>" + taskNum + "任务启动");
            Date dateTmp1 = new Date();
            Thread.sleep(1000);
            Date dateTmp2 = new Date();
            long time = dateTmp2.getTime() - dateTmp1.getTime();
            System.out.println(">>>" + taskNum + "任务终止");
            return taskNum + "任务返回运行结果,当前任务时间【" + time + "毫秒】";
        }
    }