Spring mvc interceptor配置拦截器

xml代码：

Java代码：

package com.anxin.msapweb.web.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.anxin.msapweb.common.Config;

public class SecurityInterceptor implements HandlerInterceptor {

 private static final String LOGIN_URL = "/login.htm";

 @Override
 public boolean preHandle(HttpServletRequest req, HttpServletResponse res, Object handler) throws Exception {
  HttpSession session = req.getSession(true);
  // 从session 里面获取用户名的信息
  Object obj = session.getAttribute(Config.Passport.SESSION_NAME_LOGIN_RESULT);
  // 判断如果没有取到用户信息，就跳转到登陆页面，提示用户进行登陆
  if (obj == null || "".equals(obj.toString())) {
   res.sendRedirect(LOGIN_URL);
  }
  return true;
 }

 @Override
 public void postHandle(HttpServletRequest req, HttpServletResponse res, Object arg2, ModelAndView arg3) throws Exception {
 }

 @Override
 public void afterCompletion(HttpServletRequest req, HttpServletResponse res, Object arg2, Exception arg3) throws Exception {
 }

}