下载URL的内容 -- 程序之巢2012-- 编程爱好者博客

/*
* 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>

来源： java实例中国电力出版社

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下载URL的内容2006-05-09 16:09:00

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