Hibernate+spting+struts+ajax 整合问题

大家好，请高手们指点
我的servlet文件是：
package com.ljc.rank.ajax;

import java.io.IOException;

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

import com.ljc.rank.vo.RankList;
import com.rank.service.AddUniversityMgr;

public class ModifyServlet extends HttpServlet {

private static final long serialVersionUID = 1L;
private AddUniversityMgr addUniversityMgr;

public AddUniversityMgr getAddUniversityMgr() {
return addUniversityMgr;
}

public void setAddUniversityMgr(AddUniversityMgr addUniversityMgr) {
this.addUniversityMgr = addUniversityMgr;
}

protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}

protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("utf8");
String uid = request.getParameter("uid").trim() ;
String uname = request.getParameter("uname") ;
        String ulocation = request.getParameter("ulocation") ;