从URL获取文件保存到本地的代码

<%@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 = "d:/ghost/";
  boolean flag = saveUrlAs(photoUrl, filePath + fileName);
  out.println("Run ok!\n<BR>Get URL file " + flag);
%>