Runnable与Thread区别

简述

Runnable是接口，Thread是类且实现Runnable接口

Thread线程是独立的不共享资源

Runnable是资源共享

在使用Runnable定义的子类中没有start()方法，只有Thread类中才有。

Thread类，有一个构造方法：public Thread(Runnable targer)

此构造方法接受Runnable的子类实例，也就是说可以通过Thread类来启动Runnable实现的多线程。

public Thread(Runnable runnable)  
{  
    daemon = false;  
    stillborn = false;  
    threadLocals = null;  
    inheritableThreadLocals = null;  
    threadStatus = 0;  
    blockerLock = new Object();  
    init(null, runnable, (new StringBuilder()).append("Thread-").append(nextThreadNum()).toString(), 0L);  
}  

　　

使用情况

在程序开发中只要是多线程肯定永远以实现Runnable接口为主。

实现Runnable接口相比继承Thread类有如下好处：
1、避免继承的局限，一个类可以继承多个接口。
2、适合于资源的共享。

举例

三个网友分别抢10张优惠券

继承Thread

/**
 * MyThreadWithExtends
 * 
 * @author Stephen
 * @time 2020-7-1 17:59:02
 */
public class MyThreadWithExtends extends Thread {

	private int number = 10;

	@Override
	public void run() {

		for (int i = 0; i <= 100; i++) {
			if (number > 0) {
				number--;//优惠卷减一
				System.out.println(Thread.currentThread().getName() + "顾客抢到手，剩余优惠券：" + number);
			}
		}
	}

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

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

		// 每个线程都独立，不共享资源，每个线程都抢了10张，总共抢了30张。如果真抢，就有问题了。
	}

}

　

运行结果

/**
 * MyThreadWithExtends
 * 
 * @author Stephen
 * @time 2020-7-1 17:59:59
 */
public class MyThreadWithExtends  implements Runnable {

	private int number = 10;

	@Override
	public void run() {

		for (int i = 0; i <= 100; i++) {
			if (number > 0) {
				number--;//优惠卷减一
				System.out.println(Thread.currentThread().getName() + "顾客抢到手，剩余优惠券：" + number);
			}
		}
	}

	public static void main(String[] args) {
		MyThreadWithExtends myClass = new MyThreadWithExtends();
		Thread thread1 = new Thread(myClass,"网友1");
		Thread thread2 = new Thread(myClass,"网友2");
		Thread thread3 = new Thread(myClass,"网友3");

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

}