Callable接口实现

Callable接口实现

之前学过callable, 这次再学些不一样的东西

Callable vs. Runnable

1. Callable 接口有返回值, Runnable 接口没有返回值
2. Callable 接口可以抛出异常, Runnable 接口不能抛出异常
3. 一个重写call方法，一个重写run方法
4. Callable通过Thread调用需要通过FutureTask，Runnable可以直接调用
5. Callable会有缓存

代码

Runnable

package com.example.juc;

public class TestRunnable {
    public static void main(String[] args) {
        MyThreadRun myThreadRun = new MyThreadRun();
        new Thread(myThreadRun).start();
        new Thread(myThreadRun).start();
    }
}

class MyThreadRun implements Runnable {

    @Override
    public void run() {
        System.out.println("Run");

    }
}

Run
Run

Callable

package com.example.juc;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

public class TestCallable {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        MyThreadCall myThreadCall = new MyThreadCall();
        FutureTask<Integer> integerFutureTask = new FutureTask<>(myThreadCall);
        new Thread(integerFutureTask).start();
        new Thread(integerFutureTask).start();
        Integer integer = integerFutureTask.get();
        System.out.println(integer);
    }
}


class MyThreadCall implements Callable<Integer> {

    @Override
    public Integer call() {
        System.out.println("Call");
        return 1024;
    }
}

Call
1024