使用JAVA API从FTP服务器下载文件

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import sun.net.TelnetInputStream;
import sun.net.ftp.FtpClient;

public class FtpDownload extends HttpServlet {
?@Override
?protected void doGet(HttpServletRequest req, HttpServletResponse resp)
???throws ServletException, IOException {
?? doPost(req, resp);
?}

?@Override
?protected void doPost(HttpServletRequest req, HttpServletResponse resp)
???throws ServletException, IOException {
??String ftpServer = "ftp server ip address";
??String username = "username";
??String password = "password";
??String filename = "filename";
??String path = "/path";
??FtpClient ftpClient = new FtpClient();
??ftpClient.openServer(ftpServer);
??ftpClient.login(username, password);
??if (path.length() != 0)
???ftpClient.cd(path);
??ftpClient.binary();
??TelnetInputStream is = ftpClient.get(filename);

??resp.setContentType("application/x-msdownload");
??resp.setHeader("Content-Disposition", (new StringBuilder(
????"attachment;filename=")).append(
????new String(filename.getBytes(), "ISO-8859-1")).toString());

??ServletOutputStream out = resp.getOutputStream();
??byte[] bytes = new byte[1048576];
??int c;
??while ((c = is.read(bytes)) != -1) {
???out.write(bytes, 0, c);
??}
??is.close();
??out.flush();
??out.close();
??ftpClient.closeServer();
?}

}