文件下载源码

import java.io.*;
import java.net.*;
import java.util.*;

/**
* <p>Title: 个人开发的API</p>
* <p>Description: 将指定的HTTP网络资源在本地以文件形式存放</p>
* <p>Copyright: Copyright (c) 2004</p>
* <p>Company: NewSky</p>
* @author MagicLiao
* @version 1.0
*/
public class HttpGet {

public final static boolean DEBUG = true;//调试用
private static int BUFFER_SIZE = 8096;//缓冲区大小
private Vector vDownLoad = new Vector();//URL列表
private Vector vFileList = new Vector();//下载后的保存文件名列表

/**
* 构造方法
*/
public HttpGet() {

}

/**
* 清除下载列表
*/
public void resetList() {
vDownLoad.clear();
vFileList.clear();
}

/**
* 增加下载列表项
*
* @param url String
* @param filename String
*/
public void addItem(String url, String filename) {
vDownLoad.add(url);
vFileList.add(filename);
}

/**
* 根据列表下载资源
*/
public void downLoadByList() {
String url = null;
String filename = null;

//按列表顺序保存资源
for (int i = 0; i < vDownLoad.size(); i++) {
url = (String) vDownLoad.get(i);
filename = (String) vFileList.get(i);

try {
saveToFile(url, filename);
}
catch (IOException err) {
if (DEBUG) {
System.out.println("资源[" + url + "]下载失败!!!");
}
}
}

if (DEBUG) {
System.out.println("下载完成!!!");

}
}

/**
* 将HTTP资源另存为文件
*
* @param destUrl String
* @param fileName String
* @throws Exception
*/
public void saveToFile(String destUrl, String fileName) throws IOException {
FileOutputStream fos = null;
BufferedInputStream bis = null;
HttpURLConnection httpUrl = null;
URL url = null;
byte[] buf = new byte[BUFFER_SIZE];
int size = 0;

//建立链接
url = new URL(destUrl);
httpUrl = (HttpURLConnection) url.openConnection();
//连接指定的资源
httpUrl.connect();
//获取网络输入流
bis = new BufferedInputStream(httpUrl.getInputStream());
//建立文件
fos = new FileOutputStream(fileName);

if (this.DEBUG)
System.out.println("正在获取链接[" + destUrl + "]的内容.../n将其保存为文件[" + fileName + "]");

//保存文件
while ( (size = bis.read(buf)) != -1)
fos.write(buf, 0, size);

fos.close();
bis.close();
httpUrl.disconnect();
}

/**
* 设置代理服务器
*
* @param proxy String
* @param proxyPort String
*/
public void setProxyServer(String proxy, String proxyPort) {
//设置代理服务器
System.getProperties().put("proxySet", "true");
System.getProperties().put("proxyHost", proxy);
System.getProperties().put("proxyPort", proxyPort);

}

/**
* 设置认证用户名与密码
*
* @param uid String
* @param pwd String
*/
public void setAuthenticator(String uid, String pwd) {
Authenticator.setDefault(new MyAuthenticator(uid, pwd));
}

/**
* 主方法(用于测试)
*
* @param argv String[]
*/
public static void main(String argv[]) {

HttpGet oInstance = new HttpGet();
try {
//增加下载列表（此处用户可以写入自己代码来增加下载列表）
oInstance.addItem("http://www.ebook.com/java/网络编程001.zip","./网络编程1.zip");
oInstance.addItem("http://www.ebook.com/java/网络编程002.zip","./网络编程2.zip");
oInstance.addItem("http://www.ebook.com/java/网络编程003.zip","./网络编程3.zip");
oInstance.addItem("http://www.ebook.com/java/网络编程004.zip","./网络编程4.zip");
oInstance.addItem("http://www.ebook.com/java/网络编程005.zip","./网络编程5.zip");
oInstance.addItem("http://www.ebook.com/java/网络编程006.zip","./网络编程6.zip");
oInstance.addItem("http://www.ebook.com/java/网络编程007.zip","./网络编程7.zip");
//开始下载
oInstance.downLoadByList();
}
catch (Exception err) {
System.out.println(err.getMessage());
}

}

}

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