jsp页面怎样获取session值

我在登录后，用servlet存储登录信息，为什么在jsp页面中取不到呢？请各位大虾帮帮忙！ 
Servlet主要代码： 
public void doPost(HttpServletRequest request, HttpServletResponse response) 
throws ServletException, IOException { 

response.setContentType("text/html;charset=utf-8"); 
PrintWriter out = response.getWriter(); 
HttpSession session = request.getSession();

//获取参数名称
String stateName = request.getParameter("stateType");
String userName = request.getParameter("userName");
String userPass = request.getParameter("userPass");

  if(userName == null || userName.equals("")){ 
out.println(" <script>alert('请输入用户名！');history.go(-1); </script>"); 
  }else if(userPass == null || userPass.equals("")){ 
out.println(" <script>alert('请输入密码！');history.go(-1); </script>"); 
  }else{ 
Dao dao = new DaoImpl(); 
int result = dao.getLoginUser(stateName, userName, userPass); 
if(result > 0){ 
UserEntity user = new UserEntity(); 
user.setStateManager(stateName); 
user.setUserName(userName); 
//给session赋值
session.setAttribute("user", user);
//System.out.println(user.getStateManager()); 
request.getRequestDispatcher("/Report/index.jsp").forward(request, response); 
}else{ 
out.println(" <script>alert('用户名或密码错误，请重新输入！');history.go(-1); </script>"); 
} 
  } 
} 

jsp页面代码： 
//获取session值 
UserEntity managerType = (UserEntity)session.getAttribute("user");
String manager = managerType.getStateManager();
 没有执行 怎么forward到index.jsp页面。

UserEntity managerType = (UserEntity)session.getAttribute("user"); 
String manager = managerType.getStateManager(); 
应该可以获取到值吧 你在放入session的时候并没有给statemanager字段赋值 这里抛NullPointer异常了吗貌似是url重写问题，应该将session附加到url中
将request.getRequestDispatcher("/Report/index.jsp").forward(request, response);改成下面的代码试试：
String encodedURL=response.encodeRedirectURL("/Report/index.jsp");
request.getRequestDispatcher(encodedURL).forward(request, response);