参考教程：https://blog.csdn.net/u014427391/article/details/51419521
网页访问流程：
1、只有在用户成功登录时才能访问网站链接；
2、否则跳转到登录页面或注册页面；
3、登录成功跳转到成功页面
4、登录失败继续保留在登录页面
dispatcher-servlet.xml增加如下配置：
<!-- 拦截器 -->
<mvc:interceptors>
<!-- 多个拦截器，顺序执行 -->
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="com.qs.interceptor.LoginInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>
java代码中创建包com.qs.interceptor并创建类LoginInterceptor
package com.qs.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; /** * 登录认证的拦截器 */ public class LoginInterceptor implements HandlerInterceptor{ /** * Handler执行完成之后调用这个方法 */ public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception exc) throws Exception { } /** * Handler执行之后，ModelAndView返回之前调用这个方法 */ public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { } /** * Handler执行之前调用这个方法 */ public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { //获取请求的URL String url = request.getRequestURI(); //URL:login.jsp是公开的;这个demo是除了login.jsp是可以公开访问的，其它的URL都进行拦截控制 if(url.indexOf("login")>=0){ return true; } //获取Session HttpSession session = request.getSession(); String username = (String)session.getAttribute("username"); if(username != null){ return true; } //不符合条件的，跳转到登录界面 request.getRequestDispatcher("/WEB-INF/views/login.jsp").forward(request, response); return false; } }
在controller包中添加LoginControl类
package com.qs.controller;
import javax.servlet.http.HttpSession;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class LoginControl {
@RequestMapping(value="/login")
public String login(HttpSession session,String username,String password) throws Exception{
//在Session里保存信息
session.setAttribute("username", username);
//設置session的失效時間單位為秒
session.setMaxInactiveInterval(30*60);//30分鐘
//重定向
return "redirect:test";
}
@RequestMapping(value="/logout")
public String logout(HttpSession session) throws Exception{
//清除Session
session.invalidate();
return "redirect:login";
}
}
在controller包中创建任意类放置test成功页面的跳转【也可放在上面loginControl类中】
@RequestMapping("/test")
public String test(Model model) {
String message = "SpringMVC";
//为model添加Attribute
model.addAttribute("message",message);
System.out.println("test");
return "test";
}
在src/main/webapp/WEB-INF/views中增加login.jsp和test.jsp【test.jsp作为成功页面】
<body>
<form action="login" method="post">
用户名:<input type="text" name="username" /><br>
密码:<input type="text" name="password" /><br>
<input type="submit" value="登录" />
</form>
</body>
上面为login.jsp的主要代码
test.jsp的代码如下：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://www.springframework.org/tags" prefix="spring" %>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'test.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
当前用户:${username}
<c:if test="${username!=null}">
<a href="logout">退出</a>
</c:if>
${message}
</body>
</html>