创建线程的三种方式

利用url下载网图的类：

package creatthread;
import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.IOException;
import java.net.URL;
//需要commons-io-2.6 jar包

public class WebPicDownLoad {
    

    public void download(String url, String pathName) {
    
        try {
    
            FileUtils.copyURLToFile(new URL(url), new File(pathName));
        } catch (IOException e) {
    
            e.printStackTrace();
            System.out.println("IO异常，download方法出现问题！");
        }
    }
}

1、继承Thread类:

package creatthread;

public class DownLoadContentWithThread extends Thread {
    //1、继承Thread类
    private String url;
    private String pathName;

    public DownLoadContentWithThread(String url, String pathName) {
    
        this.url = url;
        this.pathName = pathName;
    }

    //2、重写run方法
    @Override
    public void run() {
    
        WebPicDownLoad wpc = new WebPicDownLoad();
        wpc.download(this.url, this.pathName);
        System.out.println("下载" + pathName + "完成！");
    }

    public static void main(String[] args) {
    
        //3、创建目标对象
        DownLoadContentWithThread dt1 = new DownLoadContentWithThread("https://mmbiz.qpic.cn/mmbiz_jpg/xq9PqibkVAzr9bLeYf7ia7YrKlfqxlKIJz7P32mLI6RfWAsQ11Zr1NWZ40XDNyy99Q7rm6wau50mQZjTXvvjLwYg/640?wx_fmt=jpeg&wxfrom=5&wx_lazy=1&wx_co=1", "F:\\javaworkspaceforwork\\multithread\\src\\1.jpg");
        DownLoadContentWithThread dt2 = new DownLoadContentWithThread("https://cdn.jsdelivr.net/gh/justacoder99/r2coding@master/img/contentmap.3sdmma4od740.png", "F:\\javaworkspaceforwork\\multithread\\src\\2.jpg");
        DownLoadContentWithThread dt3 = new DownLoadContentWithThread("https://cn.bing.com/th?id=OHR.RobinsEgg_EN-CN2393977438_1920x1080.jpg&rf=LaDigue_1920x1080.jpg", "F:\\javaworkspaceforwork\\multithread\\src\\3.jpg");
        //4、开启线程
        dt1.start();
        dt2.start();
        dt3.start();
    }
}

2、实现Runnable接口：

package creatthread;

public class DownLoadContentWithRunnable implements Runnable {
    //1、实现Runnable接口
    private String url;
    private String pathName;

    public DownLoadContentWithRunnable(String url, String pathName) {
    
        this.url = url;
        this.pathName = pathName;
    }

    //2、重写run方法
    @Override
    public void run() {
    
        WebPicDownLoad wpc = new WebPicDownLoad();
        wpc.download(this.url, this.pathName);
        System.out.println("下载" + pathName + "完成！");
    }

    public static void main(String[] args) {
    
        //3、创建目标对象
        DownLoadContentWithRunnable dt1 = new DownLoadContentWithRunnable("https://mmbiz.qpic.cn/mmbiz_jpg/xq9PqibkVAzr9bLeYf7ia7YrKlfqxlKIJz7P32mLI6RfWAsQ11Zr1NWZ40XDNyy99Q7rm6wau50mQZjTXvvjLwYg/640?wx_fmt=jpeg&wxfrom=5&wx_lazy=1&wx_co=1", "F:\\javaworkspaceforwork\\multithread\\src\\4.jpg");
        DownLoadContentWithRunnable dt2 = new DownLoadContentWithRunnable("https://cdn.jsdelivr.net/gh/justacoder99/r2coding@master/img/contentmap.3sdmma4od740.png", "F:\\javaworkspaceforwork\\multithread\\src\\5.jpg");
        DownLoadContentWithRunnable dt3 = new DownLoadContentWithRunnable("https://cn.bing.com/th?id=OHR.RobinsEgg_EN-CN2393977438_1920x1080.jpg&rf=LaDigue_1920x1080.jpg", "F:\\javaworkspaceforwork\\multithread\\src\\6.jpg");
        //4、传入Runnable接口逇实现类对象
        //5、开启线程
        new Thread(dt1).start();
        new Thread(dt2).start();
        new Thread(dt3).start();
    }
}

3、实现Collable接口：

package creatthread;
import java.util.concurrent.*;

public class DownLoadContentWithCallable implements Callable<Boolean> {
    //1、实现Callable接口
    private String url;
    private String pathName;

    public DownLoadContentWithCallable(String url, String pathName) {
    
        this.url = url;
        this.pathName = pathName;
    }

    //2、重写call方法
    @Override
    public Boolean call() {
    
        WebPicDownLoad wpc = new WebPicDownLoad();
        wpc.download(this.url, this.pathName);
        System.out.println("下载" + pathName + "完成！");
        return true;
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
    
        //3、创建目标对象
        DownLoadContentWithCallable dt1 = new DownLoadContentWithCallable("https://mmbiz.qpic.cn/mmbiz_jpg/xq9PqibkVAzr9bLeYf7ia7YrKlfqxlKIJz7P32mLI6RfWAsQ11Zr1NWZ40XDNyy99Q7rm6wau50mQZjTXvvjLwYg/640?wx_fmt=jpeg&wxfrom=5&wx_lazy=1&wx_co=1", "F:\\javaworkspaceforwork\\multithread\\src\\7.jpg");
        DownLoadContentWithCallable dt2 = new DownLoadContentWithCallable("https://cdn.jsdelivr.net/gh/justacoder99/r2coding@master/img/contentmap.3sdmma4od740.png", "F:\\javaworkspaceforwork\\multithread\\src\\8.jpg");
        DownLoadContentWithCallable dt3 = new DownLoadContentWithCallable("https://cn.bing.com/th?id=OHR.RobinsEgg_EN-CN2393977438_1920x1080.jpg&rf=LaDigue_1920x1080.jpg", "F:\\javaworkspaceforwork\\multithread\\src\\9.jpg");

        //4、创建执行服务
        ExecutorService es = Executors.newFixedThreadPool(3);//创建固定3个线程大小的线程池
        //5、提交执行
        Future<Boolean> s1 = es.submit(dt1);
        Future<Boolean> s2 = es.submit(dt2);
        Future<Boolean> s3 = es.submit(dt3);
        //6、获取结果
        boolean b1 = s1.get();
        boolean b2 = s2.get();
        boolean b3 = s3.get();
        //输出结果
        System.out.println(b1);
        System.out.println(b2);
        System.out.println(b3);
        //7、关闭服务
        es.shutdown();
    }
}