利用SpringMVC如何實現(xiàn)一個登錄驗證攔截器功能

發(fā)布時間：2020-11-10 16:22:09 來源：億速云閱讀：159 作者：Leah 欄目：編程語言

這期內(nèi)容當(dāng)中小編將會給大家?guī)碛嘘P(guān)利用SpringMVC如何實現(xiàn)一個登錄驗證攔截器功能，文章內(nèi)容豐富且以專業(yè)的角度為大家分析和敘述，閱讀完這篇文章希望大家可以有所收獲。

本例實現(xiàn)登陸時的驗證攔截，采用SpringMVC攔截器來實現(xiàn)

當(dāng)用戶點擊到網(wǎng)站主頁時要進行攔截，用戶登錄了才能進入網(wǎng)站主頁，否則進入登陸頁面

核心代碼

首先是index.jsp,顯示鏈接

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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%>" rel="external nofollow" >
  
  <title>首頁</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" rel="external nofollow" >
  -->
 </head>
 
 <body>
   <div  align="center">
     <p><a href="loginpage.html" rel="external nofollow" >登陸</a></p>
     <p><a href="user/home.html" rel="external nofollow" >用戶中心</a></p>
     <p><a href="exception.html" rel="external nofollow" >觸發(fā)異常</a></p>
   </div>
 </body>
</html>

controller類

package com.jikexueyuan.demo.springmvc.lesson4.controller;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.jikexueyuan.demo.springmvc.lesson4.constant.Global;
import com.jikexueyuan.demo.springmvc.lesson4.exception.MyException;
import com.jikexueyuan.demo.springmvc.lesson4.model.User;
import com.jikexueyuan.demo.springmvc.lesson4.service.LoginService;

/**
 * 這個例子講解了如何定義MVC三層注解，使用@Resource進行注入，以及使用@RequestMapping、@RequestParam 、@SessionAttributes
 */

@Controller
public class LoginController extends BaseController {

  @Resource
  LoginService service;
  
  @Resource
  HttpServletRequest request;
  
  @RequestMapping("/exception")
  public void exception() throws MyException{
    throw new MyException("測試springmvc中的異常捕獲");
  }
  
  @RequestMapping("/loginpage")
  public String toLoginPage(){
    return "/WEB-INF/jsp/login.jsp";
  }
  
  @RequestMapping("/user/home")
  public String toUserHome(){
    return "/WEB-INF/jsp/userhome.jsp";
  }
  
  @RequestMapping("/logout")
  public String logout(){
    request.getSession().removeAttribute(Global.USER_SESSION_KEY);
    return "redirect:/";
  }
  
  @RequestMapping(value = "/doLogin", method = RequestMethod.POST)
  public String doLogin(@RequestParam String userName, @RequestParam String password){
    
    try {
      User user = service.doLogin(userName, password);
      request.getSession().setAttribute(Global.USER_SESSION_KEY, user);
      return "redirect:/user/home.html";
    } catch (Exception e) {
      return "/WEB-INF/jsp/login.jsp";
    }
    
  }
  
}

當(dāng)點擊用戶中心時，觸發(fā)攔截，相關(guān)配置如下

在spring-mvc.xml中加上攔截配置，攔截所有URL中包含/user/的請求，當(dāng)然請求用戶中心時就會觸發(fā)這個攔截器了

<mvc:interceptors>
    <mvc:interceptor>
      <!-- 攔截所有URL中包含/user/的請求 -->
      <mvc:mapping path="/user/**"/>
      <bean class="com.jikexueyuan.demo.springmvc.lesson4.interceptor.LoginInterceptor"></bean>
    </mvc:interceptor>
  </mvc:interceptors>

然后是bean指向的具體的interceptor類，如果session保存的用戶信息為null，則跳到login頁面，postHandle和afterCompletion方法都不執(zhí)行，反之都執(zhí)行。

package com.jikexueyuan.demo.springmvc.lesson4.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.jikexueyuan.demo.springmvc.lesson4.constant.Global;

public class LoginInterceptor implements HandlerInterceptor {

  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    Object user = request.getSession().getAttribute(Global.USER_SESSION_KEY);
    if (user == null) {
      System.out.println("尚未登錄，調(diào)到登錄頁面");
      response.sendRedirect("/loginpage.html");
      return false;
    }
    
    return true;
  }

  @Override
  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    System.out.println("postHandle");
  }

  @Override
  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    System.out.println("afterCompletion");
  }

}

上述就是小編為大家分享的利用SpringMVC如何實現(xiàn)一個登錄驗證攔截器功能了，如果剛好有類似的疑惑，不妨參照上述分析進行理解。如果想知道更多相關(guān)知識，歡迎關(guān)注億速云行業(yè)資訊頻道。

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利用SpringMVC如何實現(xiàn)一個登錄驗證攔截器功能

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