springmvc 登录拦截器
1 拦截器概念和struts2一致
2 实现拦截器
a 实现handlerinterceptor接口
public class MyInterceptor implements HandlerInterceptor { //在请求处理的方法之前执行 //如果返回true 那么执行下一个拦截器，如果返回false那么不去执行下一个拦截器 @Override public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2) throws Exception { // TODO Auto-generated method stub System.out.println("-------处理前------"); return true; } //在请求处理的方法执行之后执行 @Override public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3) throws Exception { System.out.println("-------处理后--------"); // TODO Auto-generated method stub } //在DispatcherServlet处理后执行---清理工作 @Override public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3) throws Exception { // TODO Auto-generated method stub } }
b 配置拦截器
<?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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" 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/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- configure the InternalResourceViewResolver --> <context:component-scan base-package="com.sgcc.controller"></context:component-scan> <!-- 拦截器的配置 --> <mvc:interceptors> <mvc:interceptor> <!-- 包括路径及其子路径 如果是/admin/* 拦截的是/admin/add /admin/list etc /admin/user/add不会被拦截 如果是/admin/** 上面都能拦截 --> <mvc:mapping path="/**"/> <!-- 对应的拦截器 --> <bean class="com.sgcc.interceptor.MyInterceptor"></bean> </mvc:interceptor> </mvc:interceptors> </beans>
3 如果被拦截 - 能否到达指定的页面？
使用HttpServletResponse 或者HttpServletRequest可以实现转发或重定向
1 //在请求处理的方法之前执行 2 //如果返回true 那么执行下一个拦截器，如果返回false那么不去执行下一个拦截器 3 @Override 4 public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1, 5 Object arg2) throws Exception { 6 // TODO Auto-generated method stub 7 System.out.println("-------处理前------"); 8 return true; 9 }
4 拦截器的应用--登录拦截器
package com.sgcc.interceptor; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; public class LoginInterceptor implements HandlerInterceptor { private List<String> allowedPass; public List<String> getAllowedPass() { return allowedPass; } public void setAllowedPass(List<String> allowedPass) { this.allowedPass = allowedPass; } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { // TODO Auto-generated method stub // // System.out.println("-------处理前------"); // response.sendRedirect(request.getContextPath()+"/index.jsp"); String url = request.getRequestURL().toString(); //允许哪些url不被拦截，哪些需要被拦截 //先判断session中是否有 Object user = request.getSession().getAttribute("user"); if (user!=null) { return true; } for (String temp :allowedPass) { if (url.endsWith(temp)) { return true; } } response.sendRedirect(request.getContextPath()+"/login.jsp"); return false; } //在请求处理的方法执行之后执行 @Override public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3) throws Exception { System.out.println("-------处理后--------"); // TODO Auto-generated method stub } //在DispatcherServlet处理后执行---清理工作 @Override public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3) throws Exception { // TODO Auto-generated method stub } }
配置
<?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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" 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/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- configure the InternalResourceViewResolver --> <context:component-scan base-package="com.sgcc.controller"></context:component-scan> <!-- 拦截器的配置 --> <mvc:interceptors> <mvc:interceptor> <!-- 包括路径及其子路径 拦截所有controller 如果是/admin/* 拦截的是/admin/add /admin/list etc /admin/user/add不会被拦截 如果是/admin/** 上面都能拦截 <mvc:mapping path="/product/*"/> <mvc:mapping path="/cart/*"/> --> <mvc:mapping path="/**"/> <!-- 对应的拦截器 --> <bean class="com.sgcc.interceptor.LoginInterceptor"> <property name="allowedPass"> <list> <value>login.do</value> </list> </property> </bean> </mvc:interceptor> </mvc:interceptors> </beans>
controller
package com.sgcc.controller; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import com.sgcc.entity.User; @Controller public class UserController { @RequestMapping("/login") public String Login (User user,HttpSession session){ if ("sgcc".equals(user.getName())&&"sgcc".equals(user.getPwd())) { session.setAttribute("user", user); return "redirect:/index.jsp"; } return "redirect:/login.jsp"; } @RequestMapping("/add") public String add(){ System.out.println("add"); return "redirect:/index.jsp"; } }
