SpringMVC拦截器——实现登录验证拦截器的示例代码
本例实现登陆时的验证拦截，采用SpringMVC拦截器来实现
当用户点击到网站主页时要进行拦截，用户登录了才能进入网站主页，否则进入登陆页面
核心代码
首先是index.jsp,显示链接
<%@pagelanguage="java"import="java.util.*"pageEncoding="UTF-8"%> <% Stringpath=request.getContextPath(); StringbasePath=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN"> <html> <head> <basehref="<%=basePath%>"rel="externalnofollow"> <title>首页</title> <metahttp-equiv="pragma"content="no-cache"> <metahttp-equiv="cache-control"content="no-cache"> <metahttp-equiv="expires"content="0"> <metahttp-equiv="keywords"content="keyword1,keyword2,keyword3"> <metahttp-equiv="description"content="Thisismypage"> <!-- <linkrel="stylesheet"type="text/css"href="styles.css"rel="externalnofollow"> --> </head> <body> <divstyle="margin:0auto;padding-top:100px;font-size:18px;"align="center"> <p><ahref="loginpage.html"rel="externalnofollow">登陆</a></p> <p><ahref="user/home.html"rel="externalnofollow">用户中心</a></p> <p><ahref="exception.html"rel="externalnofollow">触发异常</a></p> </div> </body> </html>
controller类
packagecom.jikexueyuan.demo.springmvc.lesson4.controller;
importjavax.annotation.Resource;
importjavax.servlet.http.HttpServletRequest;
importorg.springframework.stereotype.Controller;
importorg.springframework.web.bind.annotation.RequestMapping;
importorg.springframework.web.bind.annotation.RequestMethod;
importorg.springframework.web.bind.annotation.RequestParam;
importcom.jikexueyuan.demo.springmvc.lesson4.constant.Global;
importcom.jikexueyuan.demo.springmvc.lesson4.exception.MyException;
importcom.jikexueyuan.demo.springmvc.lesson4.model.User;
importcom.jikexueyuan.demo.springmvc.lesson4.service.LoginService;
/**
*这个例子讲解了如何定义MVC三层注解，使用@Resource进行注入，以及使用@RequestMapping、@RequestParam、@SessionAttributes
*/
@Controller
publicclassLoginControllerextendsBaseController{
@Resource
LoginServiceservice;
@Resource
HttpServletRequestrequest;
@RequestMapping("/exception")
publicvoidexception()throwsMyException{
thrownewMyException("测试springmvc中的异常捕获");
}
@RequestMapping("/loginpage")
publicStringtoLoginPage(){
return"/WEB-INF/jsp/login.jsp";
}
@RequestMapping("/user/home")
publicStringtoUserHome(){
return"/WEB-INF/jsp/userhome.jsp";
}
@RequestMapping("/logout")
publicStringlogout(){
request.getSession().removeAttribute(Global.USER_SESSION_KEY);
return"redirect:/";
}
@RequestMapping(value="/doLogin",method=RequestMethod.POST)
publicStringdoLogin(@RequestParamStringuserName,@RequestParamStringpassword){
try{
Useruser=service.doLogin(userName,password);
request.getSession().setAttribute(Global.USER_SESSION_KEY,user);
return"redirect:/user/home.html";
}catch(Exceptione){
return"/WEB-INF/jsp/login.jsp";
}
}
}
当点击用户中心时，触发拦截，相关配置如下
在spring-mvc.xml中加上拦截配置，拦截所有URL中包含/user/的请求，当然请求用户中心时就会触发这个拦截器了
<mvc:interceptors> <mvc:interceptor> <!--拦截所有URL中包含/user/的请求--> <mvc:mappingpath="/user/**"/> <beanclass="com.jikexueyuan.demo.springmvc.lesson4.interceptor.LoginInterceptor"></bean> </mvc:interceptor> </mvc:interceptors>
然后是bean指向的具体的interceptor类，如果session保存的用户信息为null，则跳到login页面，postHandle和afterCompletion方法都不执行，反之都执行。
packagecom.jikexueyuan.demo.springmvc.lesson4.interceptor;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
importorg.springframework.web.servlet.HandlerInterceptor;
importorg.springframework.web.servlet.ModelAndView;
importcom.jikexueyuan.demo.springmvc.lesson4.constant.Global;
publicclassLoginInterceptorimplementsHandlerInterceptor{
@Override
publicbooleanpreHandle(HttpServletRequestrequest,HttpServletResponseresponse,Objecthandler)throwsException{
Objectuser=request.getSession().getAttribute(Global.USER_SESSION_KEY);
if(user==null){
System.out.println("尚未登录，调到登录页面");
response.sendRedirect("/loginpage.html");
returnfalse;
}
returntrue;
}
@Override
publicvoidpostHandle(HttpServletRequestrequest,HttpServletResponseresponse,Objecthandler,ModelAndViewmodelAndView)throwsException{
System.out.println("postHandle");
}
@Override
publicvoidafterCompletion(HttpServletRequestrequest,HttpServletResponseresponse,Objecthandler,Exceptionex)throwsException{
System.out.println("afterCompletion");
}
}
至此，简单的springmvc拦截器就完成了。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。