SpringMVC -- 拦截器拦截注册登录简单实例

Love The Way You Lie 2023-10-11 11:36 80阅读 0赞

## SpringMVC – 拦截器拦截注册登录简单实例 ##

写过了一篇拦截器的原理，和实现，一般常用的是实现handlerExcption接口，重写里面的方法，做一个简单的实例测试

直接上代码

**实体类**

public class User {
        private String uname;
        private String upwd;
            public String getUname() {
            return name;
        }
    
        public void setUname(String name) {
            this.name = name;
        }
    
        public String getUpass() {
            return upass;
        }
    
        public void setUpass(String upass) {
            this.upass = upass;
        }
    
    }

**控制器**

import javax.servlet.http.HttpSession;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.RequestMapping;
    import pojo.User;
    @Controller
    public class UserController {
        /**
         * 登录页面初始化
         */
        @RequestMapping("/toLogin")
        public String initLogin() {
            return "login";
        }
        /**
         * 处理登录功能
         */
        @RequestMapping("/login")
        public String login(User user, Model model, HttpSession session) {
            System.out.println(user.getUname());
            if ("zhangsan".equals(user.getUname())
                    && "123456".equals(user.getUpwd())) {
                // 登录成功，将用户信息保存到session对象中
                session.setAttribute("user", user);
                // 重定向到主页面的跳转方法
                return "redirect:main";
            }
            model.addAttribute("msg", "用户名或密码错误，请重新登录！ ");
            return "login";
        }
        /**
         * 跳转到主页面
         */
        @RequestMapping("/main")
        public String toMain() {
            return "main";
        }
        /**
         * 退出登录
         */
        @RequestMapping("/logout")
        public String logout(HttpSession session) {
            // 清除 session
            session.invalidate();
            return "login";
        }

**自定义拦截器**

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;
    
    
    public class LoginInterceptor implements HandlerInterceptor {
        @Override
        public boolean preHandle(HttpServletRequest request,
                HttpServletResponse response, Object handler) throws Exception {
            // 获取请求的URL
            String url = request.getRequestURI();
            // login.jsp或登录请求放行，不拦截
            //  indexOf指定url路径的字符串下标，如果为-1为false
            if (url.indexOf("/toLogin") >= 0 || url.indexOf("/login") >= 0||url.indexOf("registe")) {
                return true;
            }
            // 获取 session
            HttpSession session = request.getSession();
            Object obj = session.getAttribute("user");
            if (obj != null)
                return true;
            // 没有登录且不是登录页面，转发到登录页面，并给出提示错误信息
            request.setAttribute("msg", "还没登录，请先登录！");
            // 重定向
            request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request,
                    response);
            return false;
        }
    
     
    }

**拦截器配置Spring MVC**

<mvc:interceptors>
            <mvc:interceptor>
                
                <mvc:mapping path="/**" />
                <bean class="interceptor.LoginInterceptor" />
            </mvc:interceptor>
        </mvc:interceptors>
    </beans>

**创建登录视图login.jsp**

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
        ${msg }
        <form action="${pageContext.request.contextPath }/login" method="post">
            用户名：<input type="text" name="uname" /><br>
            密码：<input type="password" name="upwd" /><br>
            <input type="submit" value="登录" />
        </form>
    </body>
    </html>

**另外几个自己随便配置。主要研制一下注册登录**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDU1MDQ5MA_size_16_color_FFFFFF_t_70]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDU1MDQ5MA_size_16_color_FFFFFF_t_70 1]

**亲测有效，自己试试**

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDU1MDQ5MA_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20190923095354351.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDU1MDQ5MA==,size_16,color_FFFFFF,t_70