JAVA多线程实现-实现Callable接口

1. 实现Callable接口

public class ImplementsCallable implements Callable<Integer> {}

2. 重写接口call()方法，即线程执行内容。

    @Override
    public Integer call() throws Exception {
Thread.currentThread().setName("Thread in Callable");
System.out.println(Thread.currentThread().getName() + " i = " + i);
return null;
    }

3. 通过创建FutureTask来执行给定的Callable

         Callable<Integer> oneCallable = new ImplementsCallable();
//Creates a FutureTask that will, upon running, execute the given Callable.
FutureTask<Integer> oneTask = new FutureTask<>(oneCallable);
//注释：FutureTask<Integer>是一个包装器，它通过接受Callable<Integer>来创建，它同时实现了Future和Runnable接口。

4. 通过new Thread(oneTask)创建线程对象。通过start()方法启动线程。

        //由FutureTask<Integer>创建一个Thread对象：
Thread oneThread = new Thread(oneTask);
oneThread.start();

完整代码：

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

public class ImplementsCallable implements Callable<Integer>{
	//尖括号中也可以是其他任意类
	public static int i = 0;

	public static void main(String[] args) {
		Thread.currentThread().setName("Thread main");

		Callable<Integer> oneCallable = new ImplementsCallable();
		//Creates a FutureTask that will, upon running, execute the given Callable.
		FutureTask<Integer> oneTask = new FutureTask<>(oneCallable);
		//注释：FutureTask<Integer>是一个包装器，它通过接受Callable<Integer>来创建，它同时实现了Future和Runnable接口。

		//由FutureTask<Integer>创建一个Thread对象：
		Thread oneThread = new Thread(oneTask);
		oneThread.start();
		print();



	}

	@Override
	public Integer call() throws Exception {
		Thread.currentThread().setName("Thread in Callable");
		System.out.println(Thread.currentThread().getName() + " i = " + i);
		return null;
	}

	public static void print() {
		i=0;
		for (i = 0; i < 10; i++) {
			System.out.println(Thread.currentThread().getName() + ":" + i);
		}
	}

}