标签:now() 服务 cat this cut 多线程 out ble util
//练习Thread,实现多线程同步下载图片
public class ThreadTest2 extends Thread{
private String url;
private String name;
public ThreadTest2(String url,String name){
this.url=url;//路径
this.name=name;//名字
}
//下载图片的执行体
@Override
public void run() {
WebDownloader webDownloader=new WebDownloader();
webDownloader.downloader(url,name);
System.out.println("下载了文件名为:"+name);
}
public static void main(String[] args) {
ThreadTest2 t1=new ThreadTest2("https://img2020.cnblogs.com/blog/2186812/202012/2186812-20201228112126269-922198589.jpg","1.jpg");
ThreadTest2 t2=new ThreadTest2("https://img2020.cnblogs.com/blog/2186812/202012/2186812-20201228112131743-1242968120.jpg","2.jpg");
ThreadTest2 t3=new ThreadTest2("https://img2020.cnblogs.com/blog/2186812/202012/2186812-20201228112139931-180392048.jpg","3.jpg");
t1.start();
t2.start();
t3.start();
}
}
//下载器
class WebDownloader{
//下载方法
public void downloader(String url,String name){
try {
FileUtils.copyURLToFile(new URL(url), new File(name));
}catch (Exception e){
e.printStackTrace();
System.out.println("IO异常");
}
}
//创建TestCallable类并继承Callable
public class TestCallable implements Callable<Boolean> {
private String url;//图片路径
private String name;//图片名字
public TestCallable(String url,String name){
this.url=url;
this.name=name;
}
//下载图片的执行体
@Override
public Boolean call() {
WebDownloader webDownloader=new WebDownloader();
webDownloader.downloader(url,name);
System.out.println("下载了文件名为:"+name);
return true;
}
public static void main(String[] args) throws Exception{
TestCallable t1=new TestCallable("https://img2020.cnblogs.com/blog/2186812/202012/2186812-20201228112126269-922198589.jpg","1.jpg");
TestCallable t2=new TestCallable("https://img2020.cnblogs.com/blog/2186812/202012/2186812-20201228112131743-1242968120.jpg","2.jpg");
TestCallable t3=new TestCallable("https://img2020.cnblogs.com/blog/2186812/202012/2186812-20201228112139931-180392048.jpg","3.jpg");
//开启执行服务 new一个线程池
ExecutorService es= Executors.newFixedThreadPool(3);//3代表3个线程
//提交执行-------t1 t2 t3表示创建的对象
Future<Boolean> f1=es.submit(t1);
Future<Boolean> f2=es.submit(t2);
Future<Boolean> f3=es.submit(t3);
//获取结果
boolean b1=f1.get();
boolean b2=f2.get();
boolean b3=f3.get();
//关闭服务
es.shutdownNow();
}
}
//下载器
class WebDownloader{
//下载方法
public void downloader(String url,String name){
try {
FileUtils.copyURLToFile(new URL(url), new File(name));
}catch (Exception e){
e.printStackTrace();
System.out.println("IO异常");
}
}
}
标签:now() 服务 cat this cut 多线程 out ble util
原文地址:https://www.cnblogs.com/lhy8116/p/14205111.html