Callable使用案例

短命女 2022-09-15 12:27 150阅读 0赞

1、两种实现方式

import java.util.concurrent.*;
    
    public class TestSubmit {
    
        public Future<String> welcome1(String name, ExecutorService executor) {
            System.out.println("方法调用线程名：" + Thread.currentThread().getName());
            return executor.submit(() -> {
                System.out.println("异步执行线程名：" + Thread.currentThread().getName()+"，执行业务中...");
                Thread.sleep(3000);
                return "hello " + name;
            });
    
           /* return executor.submit(new Callable<String>() {
                @Override
                public String call() throws Exception {
                     System.out.println("异步执行线程名：" + Thread.currentThread().getName()+"，执行业务中...");
                    Thread.sleep(3000);
                    return "hello " + name;
                }
            });*/
        }
    
        public String welcome2(String name) throws ExecutionException, InterruptedException {
            System.out.println("方法调用线程名：" + Thread.currentThread().getName());
            FutureTask<String> futureTask = new FutureTask<>(() -> {
                System.out.println("异步执行线程名：" + Thread.currentThread().getName()+"，执行业务中...");
                Thread.sleep(3000);
                return "hello " + name;
            });
            Thread t1 = new Thread(futureTask); //声明线程
            t1.start();
            return futureTask.get();
        }
        public static void main(String[] args) throws ExecutionException, InterruptedException {
            System.out.println("程序主线程名称：" + Thread.currentThread().getName()+"任务开始...");
            ExecutorService executor = Executors.newFixedThreadPool(10);
            TestSubmit testSubmit = new TestSubmit();
            Future<String> result = testSubmit.welcome1("张明", executor);
    
            System.out.println("程序主线程名称：" + Thread.currentThread().getName() + ",等待异步调用执行完中...");
    
            System.out.println("程序主线程名称：" + Thread.currentThread().getName() +" 打印结果"+result.get());
    
            executor.shutdown();
            System.out.println();
            System.out.println("---------------------------");
            System.out.println();
    
            String res =testSubmit.welcome2("王五");
            System.out.println("程序主线程名称：" + Thread.currentThread().getName() + ",等待异步调用执行完中...");
            System.out.println("程序主线程名称：" + Thread.currentThread().getName() +" 打印结果"+res);
        }
    
    }

2、输出结果

程序主线程名称：main任务开始...
    方法调用线程名：main
    程序主线程名称：main,等待异步调用执行完中...
    异步执行线程名：pool-1-thread-1，执行业务中...
    程序主线程名称：main 打印结果hello 张明
    
    ---------------------------
    
    方法调用线程名：main
    异步执行线程名：Thread-0，执行业务中...
    程序主线程名称：main,等待异步调用执行完中...
    程序主线程名称：main 打印结果hello 王五