java FutureTask使用

java FutureTask使用

public static Integer getTotal1(){
        try {
            System.out.println("开始getTotal1");
            Thread.sleep(6000);
            System.out.println("结束getTotal1");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return 1;
    }

    public static Integer getTotal2(){
        try {
            System.out.println("开始getTotal2");
            Thread.sleep(3000);
            System.out.println("结束getTotal2");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return 3;
    }

使用普通方式调用上面两个方法得到返回数据需要耗时9秒多, 一个方法6秒多,一个方法3秒多,

        long start = System.currentTimeMillis();
        System.err.print(getTotal1());
        System.err.print(getTotal2());
        long end = System.currentTimeMillis();
        System.err.print("耗时=====>"+(end-start));

使用FutureTask 则只需要6秒多就可以得到两个方法的返回数据

       long start = System.currentTimeMillis();
        Callable ca1 = new Callable(){
            @Override
            public Integer call() throws Exception {
                return getTotal1();
            }
        };
        FutureTask recharge1 = new FutureTask(ca1);
        new Thread(recharge1).start();


        Callable ca2 = new Callable(){
            @Override
            public Integer call() throws Exception {
                return getTotal2();
            }
        };
        FutureTask recharge2 = new FutureTask(ca2);
        new Thread(recharge2).start();

        System.err.print(recharge1.get());
        System.err.print("n====================n");
        System.err.print(recharge2.get());
        long end = System.currentTimeMillis();
        System.err.print("耗时=====>"+(end-start));