JSP实现远程文件下载保存到服务器指定目录中的方法

<%@page import="java.net.*,java.io.*"%>
<%!
 public boolean saveUrlAs(String photoUrl, String fileName) {
//此方法只能用户HTTP协议
  try {
   URL url = new URL(photoUrl);
   HttpURLConnection connection = (HttpURLConnection) url.openConnection();
   DataInputStream in = new DataInputStream(connection.getInputStream());
   DataOutputStream out = new DataOutputStream(new FileOutputStream(fileName));
   byte[] buffer = new byte[4096];
   int count = 0;
   while ((count = in.read(buffer)) > 0) {
    out.write(buffer, 0, count);
   }
   out.close();
   in.close();
   return true;
  }
  catch (Exception e) {
   return false;
  }
 }
public String getDocumentAt(String urlString) {
//此方法兼容HTTP和FTP协议
  StringBuffer document = new StringBuffer();
  try {
   URL url = new URL(urlString);
   URLConnection conn = url.openConnection();
   BufferedReader reader = new BufferedReader(new InputStreamReader(conn.
     getInputStream()));
   String line = null;
   while ( (line = reader.readLine()) != null) {
    document.append(line + "\n");
   }
   reader.close();
  }
  catch (MalformedURLException e) {
   System.out.println("Unable to connect to URL: " + urlString);
  }
  catch (IOException e) {
   System.out.println("IOException when connecting to URL: " + urlString);
  }
  return document.toString();
 }
%>
<%
//测试
 String photoUrl = "http://ad4.sina.com.cn/200601/12/43932_750450.jpg";
 String fileName = photoUrl.substring(photoUrl.lastIndexOf("/"));
 String filePath = "C:/test/";
 boolean flag = saveUrlAs(photoUrl, filePath + fileName);
 out.println("Run ok!\n<BR>Get URL file " + flag);
%>