Java 多线程实现方式一：继承Thread类

java 通过继承Thread类实现多线程很多简单：

只需要重写run方法即可。

比如我们分三个线程去京东下载三张图片：

1、先写个下载类：

注意导入CommonsIO 包

public class WebDownLoad {
	public void download(String url, String name) {
		try {
			FileUtils.copyURLToFile(new URL(url), new File(name));
		} catch (MalformedURLException e) {
			e.printStackTrace();
			System.out.println("url 不合法");
		} catch (IOException e) {
			e.printStackTrace();
			System.out.println("图片下载失败");
		}
	}
}

2、编写线程类在run()方法中执行下载操作：

class TDdownload extends Thread{
	private String url; // 远程路径
	private String name; // 存储路劲
	public TDdownload(String url, String name) {
		this.name = name;
		this.url = url;
	}

	@Override
	public void run() {
		WebDownLoad wd = new WebDownLoad();
		wd.download(url, name);
		System.out.println(name);
	}

3、调用start() 方法启动线程

public static void main(String[] args) {
		TDdownload td1 = new TDdownload("http://img11.360buyimg.com/n1/s450x450_jfs/t1/95372/26/10103/109107/5e181892Eb698a3bc/2033bb2f00c38f93.jpg", "电脑.jpg");
		TDdownload td2 = new TDdownload("http://img14.360buyimg.com/n1/s450x450_jfs/t1/106229/22/9051/174570/5e0d4a59E099ec5cd/2501bf3e7f96c1fb.jpg", "键盘.jpg");
		TDdownload td3 = new TDdownload("http://img13.360buyimg.com/n1/s450x450_jfs/t1/5916/10/5128/160256/5b9f0e9bEbc9f4db4/14f062751af6ce26.jpg", "鼠标.jpg");
		// 启动多线程
		td1.start();
		td2.start();
		td3.start();
	}