本次写的案例是,构建一个用户注册和登录界面,并用SpringMVC 的interceptor对用户直接登录主页权限进行限制
首先写一个domain对象,简单起见,就只写username和password属性
package lhc.domain;
public class User2 {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "User2 [username=" + username + ", password=" + password + "]";
}
}
配置web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>testspring</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<!-- 开启前端过滤器 -->
<!-- The front controller of this Spring Web application, responsible for
handling all application requests -->
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- Map all requests to the DispatcherServlet for handling -->
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 开启Spring的编码过滤器 -->
<filter>
<filter-name>Encoding</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>Encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>接下来是SpringMVC的配置文件的配置,开启注解,扫描包,开启视图解析器,配置自定义的拦截器
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 开启springm的注解 -->
<mvc:annotation-driven></mvc:annotation-driven>
<!-- 开启扫描指定位置的包 -->
<context:component-scan base-package="lhc"></context:component-scan>
<!-- 开启视图解析器 -->
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<!-- 配置自定义的拦截器 -->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**" />
<bean class="lhc.controller.LoginInterceptor" />
</mvc:interceptor>
</mvc:interceptors>
</beans>
写一个登录界面的表单,并显示错误信息
<%@ 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>
<h1>登录</h1>
<!-- 显示错误信息 -->
${msg }
<form action="${pageContext.request.contextPath }/user/login" method="post">
用户名:<input type="text" name="username" /> <br/>
密码:<input type="password" name="password"/><br/>
<input type="submit" value="submit">
</form>
</body>
</html>
写一个主页,并提供注销链接
<%@ 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>
<h1>欢迎来到主页</h1>
<h2></h2><a href="${pageContext.request.contextPath }/user/logout">注销</a></h2>
</body>
</html>
写Controller组件,由于SpringMVC架构建议不让用户直接访问jsp页面,并且直接访问的jsp页面不进行拦截.故在控制层转发到jsp页面,此时的jsp页面会被拦截
// 登录login.jsp
@RequestMapping(value = "/login", method = RequestMethod.GET)
public String ToLogin() {
return "login";
}
// 表单验证,注意方法与上面不同
@RequestMapping(value = "/login", method = RequestMethod.POST)
public String login(User2 user2, HttpSession session, HttpServletRequest request) {
String username = user2.getUsername();
String password = user2.getPassword();
//由于重点在SpringMVC,此处模拟从数据库取出数据进行表单验证
if (username != null && username.equals("tom") && password != null && password.equals("123")) {
session.setAttribute("user", user2);
//进入登录主页
return "main";
} else {
request.setAttribute("msg", "用户名或密码错误");
//返回到登录页面
return "login";
}
}
// 主页的注销处理
@RequestMapping("/logout")
public String logout(HttpSession session) {
//清除session的数据
session.invalidate();
return "login";
}
// 直接登录main.jsp主页,需要写一个拦截器进行拦截
@RequestMapping(value = "/main")
public String ToMain() {
return "main";
}
为直接访问主页设置一个拦截器
package lhc.controller;
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;
import lhc.domain.User2;
public class LoginInterceptor implements HandlerInterceptor {
@Override
public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
throws Exception {
}
@Override
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
throws Exception {
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {
//如果是登录login则放行
if (request.getRequestURL().indexOf("/login")>0) {
return true;
}
//如果已经登录过,则放行
HttpSession session =request.getSession();
User2 user = (User2)session.getAttribute("user");
if(user!=null) {
return true;
}
//没登录过又不登录login页面,转发到登录页面
request.setAttribute("msg", "你还没登录");
request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
return false;
}
}