众筹网项目实战-4后台管理系统

管理员登录

目标

识别操作系统的人的身份，控制他的行为。

思路

代码

创建工具方法执行MD5加密

/**
   * 对明文字符串进行MD5加密
   * @param source 传入的明文字符串
   * @return  加密结果
   */
  public static String md5(String source){
    // 1.判断source是否有效
    if(source == null || source.length() == 0){
      // 2.如果不是有效的字符串抛出异常
      throw  new RuntimeException(CrowdConstant.MESSAGE_STRING_INVALIDATE);
    }


    try {
      // 3.获取MessageDigest对象
      String algorithm = "md5";

      MessageDigest messageDigest = MessageDigest.getInstance(algorithm);

      // 4.获取明文字符串对应的字节数组
      byte[] bytes = source.getBytes();

      // 5.执行加密
      byte[] digest = messageDigest.digest(bytes);

      // 6.创建BigInteger对象
      int signum = 1;
      BigInteger bigInteger = new BigInteger(signum, digest);

      // 7.按照16进制将bigInteger的值
      int radix = 16;
      String encoded = bigInteger.toString(radix).toUpperCase();

      return encoded;
    } catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
    }

    return  null;
  }

创建登录失败异常

package com.atguigu.crowd.exception;

/**
 * 登录失败后抛出的异常
 */
public class LoginFailedException extends RuntimeException{
  private static final long serialVersionUID= 1L;

  public LoginFailedException() {
    super();
  }

  public LoginFailedException(String message) {
    super(message);
  }

  public LoginFailedException(String message, Throwable cause) {
    super(message, cause);
  }

  public LoginFailedException(Throwable cause) {
    super(cause);
  }

  protected LoginFailedException(String message, Throwable cause, boolean enableSuppression,
      boolean writableStackTrace) {
    super(message, cause, enableSuppression, writableStackTrace);
  }
}

在异常处理器类中增加登录失败异常的处理

package com.atguigu.crowd.mvc.config;

import com.atguigu.crowd.constant.CrowdConstant;
import com.atguigu.crowd.exception.LoginFailedException;
import com.atguigu.crowd.util.CrowdUtil;
import com.atguigu.crowd.util.ResultEntity;
import com.google.gson.Gson;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;

//@ControllerAdvice表示当前类是一个基于注解的异常处理器类
@ControllerAdvice
public class CrowdExceptionResolver {

  //@ExceptionHandler将一个具体的异常类型和一个方法关联起来
  @ExceptionHandler(value = Exception.class)
  public ModelAndView resolveException(
      //实际捕获到的异常类型
      Exception exception,
      //当前请求对象
      HttpServletRequest request,
      //当前响应对象
      HttpServletResponse response) throws IOException {
    String viewName = "system-error";
    return commonResolve(viewName,exception,request,response);
  }

  //@ExceptionHandler将一个具体的异常类型和一个方法关联起来
  @ExceptionHandler(value = LoginFailedException.class)
  public ModelAndView resolveLoginFailedException(
      //实际捕获到的异常类型
      LoginFailedException exception,
      //当前请求对象
      HttpServletRequest request,
      //当前响应对象
      HttpServletResponse response) throws IOException {
    String viewName = "admin-login";
    return commonResolve(viewName,exception,request,response);
  }

  /**
   * 核心异常处理方法
   * @param exception SpringMVC 捕获到的异常对象
   * @param request 为了判断当前请求是“普通请求”还是“Ajax 请求” 需要传入原生 request 对象
   * @param response 为了能够将 JSON 字符串作为当前请求的响应数
  据返回给浏览器
   * @param viewName 指定要前往的视图名称
   * @return ModelAndView
   * @throws IOException
   */
  private ModelAndView commonResolve(
      //异常页面
      String viewName,
      //实际捕获到的异常类型
      Exception exception,
      //当前请求对象
      HttpServletRequest request,
      //当前响应对象
      HttpServletResponse response) throws IOException {
    {
      //1.判断当前请求类型
      boolean b = CrowdUtil.judgeRequestType(request);
      //2.如果是Ajax请求
      if(b){
        //3.创建ResultEntity对象
        ResultEntity<Object> resultEntity = ResultEntity.failed(exception.getMessage());

        //4.创建Gson对象
        Gson gson = new Gson();

        //5.将ResultEntity对象转换为JSON字符串
        String json = gson.toJson(resultEntity);

        //6.将JSON字符串作为响应体返回给浏览器
        response.getWriter().write(json);

        //7.由于上面已经通过原生的response对象返回了响应，所以不提供ModelAndView对象
        return null;
      }
      //8.如果不是Ajax请求则创建ModelAndView对象
      ModelAndView modelAndView = new ModelAndView();

      //9.将Exception对象存入模型
      modelAndView.addObject(CrowdConstant.ATTR_NAME_EXCEPTION,exception);

      //10.设置对应的视图名称
      modelAndView.setViewName(viewName);

      //11.返回ModelAndView对象
      return modelAndView;
    }

  }

}

在登录页面显示异常消息

        <p>${requestScope.exception.message}</p>

Handler层方法

新建临时主页

<%--
  Created by IntelliJ IDEA.
  User: wangchenze.kuangwang
  Date: 2022/11/3
  Time: 20:42
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
  <h1>主页</h1>
  <p>${sessionScope.loginAdmin.userName}</p>
  </body>
</html>

package com.atguigu.crowd.mvc.handler;

import com.atguigu.crowd.constant.CrowdConstant;
import com.atguigu.crowd.entity.Admin;
import com.atguigu.crowd.service.api.AdminService;
import javax.servlet.http.HttpSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class AmdinHandler {

  @Autowired
  private AdminService adminService;

  @RequestMapping("admin/do/login.html")
  public String doLogin(@RequestParam("loginAcct") String loginAcct,
      @RequestParam("userPswd")String userPswd,
      HttpSession session
      ){
    // 调用Service方法执行登录检查
    // 这个方法如果能够返回admin对象说明登录成功，如果账号、密码不正确则会抛出异常
    Admin admin = adminService.getAdminByLoginAcct(loginAcct,userPswd);

    // 将登录成功返回的admin对象存入Session域
    session.setAttribute(CrowdConstant.ATTR_NAME_LOGIN_ADMIN,admin);

    return "admin-main";
  }

}

service层代码

@Override
    public Admin getAdminByLoginAcct(String loginAcct, String userPswd) {

        // 1.根据登录账号查询Admin对象
        // ①创建AdminExample对象
        AdminExample adminExample = new AdminExample();

        // ②创建Criteria对象
        Criteria criteria = adminExample.createCriteria();

        // ③在Criteria对象中封装查询条件
        criteria.andLoginAcctEqualTo(loginAcct);

        // ④调用AdminMapper的方法执行查询
        List<Admin> admins = adminMapper.selectByExample(adminExample);

        // 2.判断Admin对象是否为null
        if(admins == null || admins.size() == 0){
            throw new LoginFailedException(CrowdConstant.MESSAGE_LOGIN_FAILED);
        }

        if(admins.size() > 1){
            throw new RuntimeException(CrowdConstant.MESSAGE_SYSTEM_ERROR_LOGIN_NOT_UNIQUE);
        }
        // 3.如果Admin对象为null则抛出异常
        Admin admin = admins.get(0);
        if(admin == null){
            throw new RuntimeException(CrowdConstant.MESSAGE_SYSTEM_ERROR_LOGIN_NOT_UNIQUE);
        }

        // 4.如果Admin对象不为null则将数据库密码从Admin对象中取出
        String userPswdDB = admin.getUserPswd();

        // 5.将表单提交的明文密码进行加密
        String userPswdForm = CrowdUtil.md5(userPswd);
        // 6.对密码进行比较
        if(!Objects.equals(userPswdDB,userPswdForm)){
            // 7.如果比较结果是不一致则抛出异常
            throw new LoginFailedException(CrowdConstant.MESSAGE_LOGIN_FAILED);
        }

        // 8.如果一致则返回Admin对象
        return admin;
    }

补充

前往后台主页面的方式调整

为了避免跳转到后台主页面再刷新浏览器导致重复提交登录表单，重定向到目标页面。
所以handler方法需要做相应修改

  @RequestMapping("admin/do/login.html")
  public String doLogin(@RequestParam("loginAcct") String loginAcct,
      @RequestParam("userPswd")String userPswd,
      HttpSession session
      ){
    // 调用Service方法执行登录检查
    // 这个方法如果能够返回admin对象说明登录成功，如果账号、密码不正确则会抛出异常
    Admin admin = adminService.getAdminByLoginAcct(loginAcct,userPswd);

    // 将登录成功返回的admin对象存入Session域
    session.setAttribute(CrowdConstant.ATTR_NAME_LOGIN_ADMIN,admin);

    return "redirect:/admin/to/main/page.html";
  }

添加调转映射

退出登录

修改页面

编写handler

  @RequestMapping("/admin/do/logout.html")
  public String doLogout(HttpSession session){
    //强制Session失效
    session.invalidate();

    return "redirect:/admin/to/login/page.html";
  }

抽取后台主页面公共部分

创建公共部分jsp

<%--
  Created by IntelliJ IDEA.
  User: wangchenze.kuangwang
  Date: 2022/11/4
  Time: 15:46
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="description" content="">
    <meta name="author" content="">
    <base href="http://${pageContext.request.serverName}:${pageContext.request.serverPort}${pageContext.request.contextPath}/"/>
    <link rel="stylesheet" href="bootstrap/css/bootstrap.min.css">
    <link rel="stylesheet" href="css/font-awesome.min.css">
    <link rel="stylesheet" href="css/main.css">
    <style>
      .tree li {
        list-style-type: none;
        cursor:pointer;
      }
      .tree-closed {
        height : 40px;
      }
      .tree-expanded {
        height : auto;
      }
    </style>
    <script type="text/javascript" src="jquery/jquery-2.1.1.min.js"></script>
    <script type="text/javascript" src="bootstrap/js/bootstrap.min.js"></script>
    <script type="text/javascript" src="script/docs.min.js"></script>
    <script type="text/javascript" src="layer/layer.js"></script>
    <script type="text/javascript">
      $(function () {
        $(".list-group-item").click(function(){
          if ( $(this).find("ul") ) {
            $(this).toggleClass("tree-closed");
            if ( $(this).hasClass("tree-closed") ) {
              $("ul", this).hide("fast");
            } else {
              $("ul", this).show("fast");
            }
          }
        });
      });
    </script>
</head>

<%--
  Created by IntelliJ IDEA.
  User: wangchenze.kuangwang
  Date: 2022/11/4
  Time: 15:54
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<nav class="navbar navbar-inverse navbar-fixed-top" role="navigation">
    <div class="container-fluid">
        <div class="navbar-header">
            <div><a class="navbar-brand" style="font-size:32px;" href="#">众筹平台 - 控制面板</a></div>
        </div>
        <div id="navbar" class="navbar-collapse collapse">
            <ul class="nav navbar-nav navbar-right">
                <li style="padding-top:8px;">
                    <div class="btn-group">
                        <button type="button" class="btn btn-default btn-success dropdown-toggle" data-toggle="dropdown">
                            <i class="glyphicon glyphicon-user"></i> ${sessionScope.loginAdmin.userName} <span class="caret"></span>
                        </button>
                        <ul class="dropdown-menu" role="menu">
                            <li><a href="#"><i class="glyphicon glyphicon-cog"></i> 个人设置</a></li>
                            <li><a href="#"><i class="glyphicon glyphicon-comment"></i> 消息</a></li>
                            <li class="divider"></li>
                            <li><a href="admin/do/logout.html"><i class="glyphicon glyphicon-off"></i> 退出系统</a></li>
                        </ul>
                    </div>
                </li>
                <li style="margin-left:10px;padding-top:8px;">
                    <button type="button" class="btn btn-default btn-danger">
                        <span class="glyphicon glyphicon-question-sign"></span> 帮助
                    </button>
                </li>
            </ul>
            <form class="navbar-form navbar-right">
                <input type="text" class="form-control" placeholder="查询">
            </form>
        </div>
    </div>
</nav>

抽取后效果

<%--
  Created by IntelliJ IDEA.
  User: wangchenze.kuangwang
  Date: 2022/11/3
  Time: 20:42
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<!DOCTYPE html>
<html lang="zh-CN">
<%@include file="/WEB-INF/include-head.jsp"%>

<body>

<%@ include file="/WEB-INF/include-nav.jsp" %>
<div class="container-fluid">
    <div class="row">

        <div class="col-sm-9 col-sm-offset-3 col-md-10 col-md-offset-2 main">
            <h1 class="page-header">控制面板</h1>
            <%@ include file="/WEB-INF/include-sidebar.jsp"%>
            <div class="row placeholders">
                <div class="col-xs-6 col-sm-3 placeholder">
                    <img data-src="holder.js/200x200/auto/sky" class="img-responsive" alt="Generic placeholder thumbnail">
                    <h4>Label</h4>
                    <span class="text-muted">Something else</span>
                </div>
                <div class="col-xs-6 col-sm-3 placeholder">
                    <img data-src="holder.js/200x200/auto/vine" class="img-responsive" alt="Generic placeholder thumbnail">
                    <h4>Label</h4>
                    <span class="text-muted">Something else</span>
                </div>
                <div class="col-xs-6 col-sm-3 placeholder">
                    <img data-src="holder.js/200x200/auto/sky" class="img-responsive" alt="Generic placeholder thumbnail">
                    <h4>Label</h4>
                    <span class="text-muted">Something else</span>
                </div>
                <div class="col-xs-6 col-sm-3 placeholder">
                    <img data-src="holder.js/200x200/auto/vine" class="img-responsive" alt="Generic placeholder thumbnail">
                    <h4>Label</h4>
                    <span class="text-muted">Something else</span>
                </div>
            </div>
        </div>
    </div>
</div>

</body>
</html>

创建jsp模板

<%--
  Created by IntelliJ IDEA.
  User: wangchenze.kuangwang
  Date: 2022/11/3
  Time: 20:42
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<!DOCTYPE html>
<html lang="zh-CN">
<%@include file="/WEB-INF/include-head.jsp"%>

<body>

<%@ include file="/WEB-INF/include-nav.jsp" %>
<div class="container-fluid">
    <div class="row">

        <div class="col-sm-9 col-sm-offset-3 col-md-10 col-md-offset-2 main">

        </div>
    </div>
</div>

</body>
</html>

登录状态检查

目标

将部分资源保护起来，让没有登录的请求不能访问。

思路

代码

创建自定义异常

创建拦截器类

注册拦截器类

  <mvc:interceptors>
    <mvc:interceptor>



      <mvc:mapping path="/**"/>

      <mvc:exclude-mapping path="/admin/to/login/page.html"/>
      <mvc:exclude-mapping path="/admin/do/login.html"/>
      <mvc:exclude-mapping path="/admin/do/logout.html"/>

      <bean class="com.atguigu.crowd.mvc.interceptor.LoginInterceptor">bean>
    mvc:interceptor>
  mvc:interceptors>