springmvc拦截器

        处理请求前，被执行preHandle

        处理请求后，数据渲染前，被执行postHandle

        处理请求后，数据渲染后，被执行afterCompletion

        index.jsp中的内容

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

  
    
  
  
  欢迎进入springmvc的世界
  欢迎
  


    账    号:

    密    码:

    

  
  

        springmvc.xml中的配置文件

        interceptor拦截器中的内容（idea中没有提示的话，ctrl+o）

package org.zmt.intercertor;

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

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

public class LoginInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //拿到浏览器后缀地址
        String uri = request.getRequestURI();
        //拿到账号密码
        String name = request.getParameter("name");
        String pwd = request.getParameter("password");

        //后缀为login或者Login时
        if (uri.contains("Login")||uri.contains("login")){
            //对账号或者密码进行判断
            if (name != null & name != "" & pwd != null & pwd != ""){
                return true;
            }else {

                //转发
                request.getRequestDispatcher("/index.jsp").forward(request, response);
            }
        }else {
            //重定向
            response.sendRedirect(request.getContextPath()+"/tologin");
        }
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

        controller中的内容

package org.zmt.controller;

import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;
import sun.rmi.runtime.Log;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import java.lang.annotation.Annotation;

@Controller
public class HelloController {

    @RequestMapping("/hello")
    public ModelAndView hello(){
        System.out.println("执行业务逻辑");
        ModelAndView mv = new ModelAndView();
        mv.addObject("lj","说的就是你！");
        mv.setViewName("show");
        return mv;
    }
    @RequestMapping("/login")
    public ModelAndView login(HttpServletRequest request){
        String name = request.getParameter("name");
        ModelAndView mv = new ModelAndView();
        mv.addObject("name",name);
        mv.setViewName("login");
        return mv;
    }

    @RequestMapping("/tologin")
    public String toLogin(){
        return "index";
    }
}

        登录成功后的页面login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


欢迎

账    号:${name}

        接下来进行测试就行了