在线等：servlet显示FTP的图片
求大神帮忙解决 


jsp展示图片，url指向servlet展示图片 ，图片在ftp上 

用到ftpClent类


我则呢吗也展示不出来，望路过大神指点小弟一下

------解决方案--------------------
apache common-net包直接读取ftp上出来的图片流替换servlet中的流

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;



import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;





import org.activiti.engine.IdentityService;

import org.activiti.engine.identity.Picture;

import org.apache.shiro.SecurityUtils;

import org.apache.shiro.subject.Subject;

import org.springframework.web.context.WebApplicationContext;

import org.springframework.web.context.support.WebApplicationContextUtils;





/**

 * Servlet implementation class ShowPic

 */

@WebServlet("/ShowPic.slt")

public class ShowPicServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;



	private IdentityService identityService;



	/**

	 * @see HttpServlet#HttpServlet()

	 */

	public ShowPicServlet() {

		super();

	}





	/*

	 * （非 Javadoc）

	 * 

	 * @see javax.servlet.http.HttpServlet#service(javax.servlet.ServletRequest,

	 * javax.servlet.ServletResponse)

	 */

	@Override

	public void service(ServletRequest request, ServletResponse response)

			throws ServletException, IOException {

		

		//通过spring配置初始化服务对象

		ServletContext application = getServletContext();  

		WebApplicationContext wac = WebApplicationContextUtils.getWebApplicationContext(application);// 获取spring的context  

		identityService = (IdentityService)wac.getBean("identityService");

		

		Subject currentUser = SecurityUtils.getSubject();

		Picture userPicture = identityService.getUserPicture(currentUser.getPrincipal().toString());