Go语言视频零基础入门到精通

javalearner

/*
  * Copyright (c) 2000 David Flanagan.  All rights reserved.
  * This code is from the book java Examples in a Nutshell, 2nd Edition.
  * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
  * You may study, use, and modify it for any non-commercial purpose.
  * You may distribute it non-commercially as long as you retain this notice.
  * For a commercial use license, or to purchase the book (recommended),
  * visit http://www.davidflanagan.com/javaexamples2.
  */
import java.io.*;
import java.net.*;

/**
  *  这个简单的程序使用URL及其openStream()方法下载
  *  URL内容并复制到文件或后台。
  **/
public class GetURL {
     public static void main(String[] args) {
         InputStream in = null;   
         OutputStream out = null;
         try {
             // 检测参数
             if ((args.length != 1)&& (args.length != 2))  
                 throw new IllegalArgumentException("Wrong number of args");
      
             // 设置流
             URL url = new URL(args[0]);   //创建URL
             in = url.openStream();        // 打开一个流
             if (args.length == 2)         // 获取相应的输出流
                 out = new FileOutputStream(args[1]);
             else out = System.out;
      
             // 从URL复制字节到输出流
             byte[] buffer = new byte[4096];
             int bytes_read;
             while((bytes_read = in.read(buffer)) != -1)
                 out.write(buffer, 0, bytes_read);
}
         // On exceptions, print error message and usage message.
         catch (Exception e) {
             System.err.println(e);
             System.err.println("Usage: java GetURL <URL> [<filename>]");
         }
         finally {  // 永远记住关闭流。
             try { in.close();  out.close(); } catch (Exception e) {}
         }
     }
}


运行方法：

C:java>java     GetURL  http://127.0.0.1:8080/zz3zcwbwebhome/     home.HTML

C:java>