Java并发编程初级篇(一)：线程实现与运行的两种方式-优快云博客

本文介绍了两种Java线程创建方式：一是通过继承Thread类，二是通过实现Runnable接口。对比了这两种方式的不同之处，并通过示例代码展示了它们的使用方法。

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通过继承Thread类来实现一个线程

线程的创建：

public class MyThread extends Thread {
    private int num = 5;

    @Override
    public void run() {
        while (num > 0) {
            System.out.println("Thread:" + Thread.currentThread().getName() + ", consume " + num);
            num--;
            try {
                sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

线程的运行：

public static void main(String[] args) {
    MyThread thread1 = new MyThread();
    MyThread thread2 = new MyThread();
    MyThread thread3 = new MyThread();

    thread1.start();
    thread2.start();
    thread3.start();
}

运行结果：

Thread:Thread-0, consume 5
Thread:Thread-1, consume 5
Thread:Thread-2, consume 5
Thread:Thread-0, consume 4
Thread:Thread-2, consume 4
Thread:Thread-1, consume 4
Thread:Thread-0, consume 3
Thread:Thread-1, consume 3
Thread:Thread-2, consume 3
Thread:Thread-0, consume 2
Thread:Thread-2, consume 2
Thread:Thread-1, consume 2
Thread:Thread-0, consume 1
Thread:Thread-2, consume 1
Thread:Thread-1, consume 1

通过实现Runnable接口来实现一个线程

线程的创建：

public class MyRunnable implements Runnable {
    private int num = 5;

    @Override
    public void run() {
        while (num > 0) {
            System.out.println("Thread:" + Thread.currentThread().getName() + ", consume " + num);
            num--;
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

第一种运行方式：

public static void main(String[] args) {
    Thread thread1 = new Thread(new MyRunnable());
    Thread thread2 = new Thread(new MyRunnable());
    Thread thread3 = new Thread(new MyRunnable());

    thread1.start();
    thread2.start();
    thread3.start();
}

第一种方式运行结果：

Thread:Thread-0, consume 5
Thread:Thread-2, consume 5
Thread:Thread-1, consume 5
Thread:Thread-0, consume 4
Thread:Thread-2, consume 4
Thread:Thread-1, consume 4
Thread:Thread-2, consume 3
Thread:Thread-1, consume 3
Thread:Thread-0, consume 3
Thread:Thread-1, consume 2
Thread:Thread-0, consume 2
Thread:Thread-2, consume 2
Thread:Thread-1, consume 1
Thread:Thread-2, consume 1
Thread:Thread-0, consume 1

第二种运行方式：

public static void main(String[] args) {
	Runnable runnable = new MyRunnable();

	Thread thread1 = new Thread(runnable);
	Thread thread2 = new Thread(runnable);
	Thread thread3 = new Thread(runnable);
        
	thread1.start();
	thread2.start();
	thread3.start();
}

第二种方式运行结果：

Thread:Thread-0, consume 5
Thread:Thread-1, consume 4
Thread:Thread-2, consume 3
Thread:Thread-0, consume 2
Thread:Thread-1, consume 1

总结：

通过继承Thread类和实现Runnable接口都能够实现一个线程，但是实现Runnable接口创建的线程类可以交给多个Thread来运行。这类似于需要加工30个零件，第一种方式为交给三个人去做每个人加工10个零件，完成时间取决于最慢的哪个人；第二种方式为一共30个零件交给3个人去加工，速度快的人会为速度慢的人分担加工的零件，总体速度会提升。

转载于:https://my.oschina.net/nenusoul/blog/791336