springMVC-拦截器
1 基本环境搭建
1.1 创建普通maven项目,添加web支持
1.2 配置web.xml
1.3 配置springmvc配置文件 applicationContext.xml
1.4 创建控制层和拦截器层的两个包
2 简单测试拦截器
2.1 在拦截器层创建一个拦截器类
package com.lv.config; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class MyInterceptor implements HandlerInterceptor { //return true; 执行下一个拦截器,放行 //return false; 不执行下一个拦截器 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("=======处理前======="); return false; } //日志 @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("=======处理后======="); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("=======清理======="); } }
2.2 在springmvc配置文件中配置拦截器
<!--拦截器配置--> <mvc:interceptors> <mvc:interceptor> <!--包括这个请求下面的所有请求--> <mvc:mapping path="/**"/> <bean class="com.lv.config.MyInterceptor"/> </mvc:interceptor> </mvc:interceptors>
2.3 在控制层新建一个Controller
package com.lv.controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class TestController { @GetMapping("/t1") public String test(){ System.out.println("TestController==>test()方法执行了"); return "OK"; } }
2.4 启动Tomcat测试
2.5 查看后台输出
3 拦截器实现登录验证
3.1 编写index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <h1><a href="${pageContext.request.contextPath}/user/goLogin">登录页面</a></h1> <h1><a href="${pageContext.request.contextPath}/user/main">首页</a></h1> </body> </html>
3.2 编写登录页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <%--在WEB-INF目录下的所有页面或资源,只能通过controller,或者servlet进行访问--%> <h1>登录页面</h1> <form action="${pageContext.request.contextPath}/user/login" method="post"> 用户名:<input type="text" name="username" required/> 密码:<input type="text" name="password" required/> <input type="submit"> </form> </body> </html>
3.3 编写首页
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <h1>首页</h1> <span>${username}</span> <p> <a href="${pageContext.request.contextPath}/user/goOut">注销</a> </p> </body> </html>
3.4 创建一个Controller
package com.lv.controller; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import javax.servlet.http.HttpSession; @Controller @RequestMapping("/user") public class LoginController { @RequestMapping("/goLogin") public String login(){ return "login"; } @RequestMapping("/login") public String login(HttpSession session, String username, String password, Model model){ //把用户的信息存在session中 session.setAttribute("userLoginInfo",username); model.addAttribute("username",username); return "main"; } @RequestMapping("/main") public String main(){ return "main"; } @RequestMapping("/goOut") public String goOut(HttpSession session){ session.removeAttribute("userLoginInfo"); return "login"; } }
3.5 编写用户登录拦截器
package com.lv.config; import org.springframework.web.servlet.HandlerInterceptor; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class LoginInterceptor implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { HttpSession session = request.getSession(); //放行: 判断什么情况下登录 //登录页面会放行 if (request.getRequestURI().contains("goLogin")){ return true; } //提交登录放行 if (request.getRequestURI().contains("login")){ return true; } //已经登录成功放行 if (session.getAttribute("userLoginInfo") != null){ return true; } //没有登录的情况 request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request,response); return false; } }
3.6 在springmvc配置文件中配置拦截器
<!--拦截器配置--> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/user/**"/> <bean class="com.lv.config.LoginInterceptor"/> </mvc:interceptor> </mvc:interceptors>
3.7 启动Tomcat测试
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