SpringMVC基础-14-拦截器使用案例-权限控制

pom.xml

  4.0.0
  com.monkey1024
  03mvc
  0.0.1-SNAPSHOT
  war
  
        
            junit
            junit
            3.8.1
            test
        
        
            javax.servlet
            javax.servlet-api
            3.1.0
        
        
            org.springframework
            spring-webmvc
            5.0.4.RELEASE
        
 
    
    
    	
        03mvc
        
            
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    
                    1.8
                    1.8
                    UTF-8
                
            
        
    

web.xml

  
    springMVC
    org.springframework.web.servlet.DispatcherServlet
    
      contextConfigLocation
      classpath:springmvc.xml
    
    1
  
  
    springMVC
    *.do
  

springmvc.xml

PermissionInterceptor.java

package com.monkey1024.interceptor;

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

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

/*
 * 权限拦截器
 */
public class PermissionInterceptor implements HandlerInterceptor {
	public  boolean preHandle(HttpServletRequest request,HttpServletResponse response,Object handler) throws Exception{
		System.out.println("拦截器中的preHandle方法");
		String user = (String) request.getSession().getAttribute("user");
		//判断用户名为monkey1024的用户是否已登录
		if(!"monkey1024".equals(user)){
			request.getRequestDispatcher("/jsp/fail.jsp").forward(request, response);
			//不进行后续处理
			return false;
		}
		return true;
	}
	public void postHandle(HttpServletRequest request,HttpServletResponse response,Object handler,ModelAndView modelAndView) throws Exception{
		System.out.println("拦截器中的postHandle方法");
		
	}
	public void afterCompletion(HttpServletRequest request,HttpServletResponse response,Object handler,Exception ex) throws Exception{
		System.out.println("拦截器中的afterCompletion方法");
		
	}
}

LoginController.java

package com.monkey1024.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

/*
 * 登陆
 */
@Controller
public class LoginController {
	@RequestMapping("/welcome.do")
	public ModelAndView welcome() throws Exception{
		ModelAndView mv = new ModelAndView();
		mv.addObject("welcome","欢迎登陆本系统");
		mv.setViewName("/welcome");
		return mv;
	}
}

fail.jsp

Insert title here


登录失败

welcome.jsp

Insert title here


${welcome }

login.jsp

Insert title here