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[JavaScript知识库]用户信息管理系统（Web实践项目）

一、简单功能

1.列表查询

在这里插入图片描述

2.登录

登录时要先校验验证码是否正确，再去校验账号密码，密码正确后将用户存入session。

前端代码：

 <script type="text/javascript">
        //切换验证码
        function refreshCode() {
            //1.获取验证码图片对象
            var vcode=document.getElementById("vcode");
            //2.设置其src属性，加时间戳
            vcode.src="${pageContext.request.contextPath}/checkCodeServlet?time="+new Date().getTime();
        }
    </script>

后端servlet代码：

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.设置编码
        request.setCharacterEncoding("utf-8");

        //2.获取数据
        //2.1获取用户填写的验证码
        String verifycode = request.getParameter("verifycode");

        //3.验证码校验
        HttpSession session = request.getSession();
        String checkcode_server =(String) session .getAttribute("CHECKCODE_SERVER");
        session.removeAttribute("CHECKCODE_SERVER");//确保验证码一次性
        if(!checkcode_server.equalsIgnoreCase(verifycode)){
        //验证码不正确
            //提示信息
            request.setAttribute("login_msg","验证码错误!");
            //跳转登录页面
            request.getRequestDispatcher("/login.jsp").forward(request,response);

            return;

        }

        Map<String, String[]> map = request.getParameterMap();
        //4.封装user对象
        User user=new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }


        //5.调用Service查询
        UserService service=new UserServiceImpl();
        User loginUser =service.login(user);
        //6.判断是否登录成功
        if(loginUser !=null){
            //登录成功
            //将用户存入session
            session.setAttribute("user",loginUser);
            //跳转页面
            response.sendRedirect(request.getContextPath()+"/index.jsp");

        }else{
            //登录失败
            //提示信息
            request.setAttribute("login_msg","用户名或密码错误!");
            //跳转登录页面
            request.getRequestDispatcher("/login.jsp").forward(request,response);
        }


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

测试结果：
用户名或密码错误
在这里插入图片描述
验证码错误

验证码，用户名和密码都输入正确后会进入下一个页面

3.添加

在这里插入图片描述

前端代码：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<!-- HTML5文档-->
<!DOCTYPE html>
<!-- 网页使用的语言 -->
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>添加用户</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    </head>
<body>
<div class="container">
    <center><h3>添加联系人页面</h3></center>
    <form action="${pageContext.request.contextPath}/addUserServlet" method="post" id="form">
        <div class="form-group">
            <label for="name">姓名：</label>
            <input type="text" class="form-control" id="name" name="name" placeholder="请输入姓名">
        </div>

        <div class="form-group">
            <label>性别：</label>
            <input type="radio" name="gender" value="男" checked="checked"/>男
            <input type="radio" name="gender" value="女"/>女
        </div>

        <div class="form-group">
            <label for="age">年龄：</label>
            <input type="text" class="form-control" id="age" name="age" placeholder="请输入年龄">
        </div>

        <div class="form-group">
            <label for="address">籍贯：</label>
            <select name="address" class="form-control" id="address">
                <option value="陕西">陕西</option>
                <option value="北京">北京</option>
                <option value="上海">上海</option>
            </select>
        </div>

        <div class="form-group">
            <label for="qq">QQ：</label>
            <input type="text" class="form-control" id="qq" name="qq" placeholder="请输入QQ号码"/>
        </div>

        <div class="form-group">
            <label for="email">Email：</label>
            <input type="text" class="form-control" id="email" name="email" placeholder="请输入邮箱地址"/>
        </div>

        <div class="form-group" style="text-align: center">
            <input class="btn btn-primary" type="submit" value="提交" />
            <input class="btn btn-default" type="reset" value="重置" />
            <input class="btn btn-default" type="button" value="返回" />
        </div>
    </form>
</div>
</body>
</html>

后端代码：

@WebServlet("/addUserServlet")
public class AddUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.设置编码
        request.setCharacterEncoding("utf-8");
        //2.获取参数
        Map<String, String[]> map = request.getParameterMap();
        //3.封装对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //4.调用service保存
        UserService service=new UserServiceImpl();
        service.addUser(user);

            //5.跳转到userListServlet
            response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

4.删除

在这里插入图片描述
删除信息时，给出提示，避免用户误删
前端代码：

 function deleteUser(id) {
        //用户安全提示
            if(confirm("您确定要删除吗？")){
        //访问路径
                location.href="${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }

后端代码：

@WebServlet("/delSelectedServlet")
public class DelSelectedServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //1.获取所有的id
        String[] ids = request.getParameterValues("uid");
        //调用service删除
        UserService service = new UserServiceImpl();
        service.delSelectedUser(ids);

        //3.跳转查询所有servlet
        response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

5.修改

在这里插入图片描述
修改用户信息要使数据能够回显信息，方便用户修改信息

前端代码：

设置隐藏域

  <%--隐藏域 提交id--%>
            <input type="hidden" name="id" value="${user.id}">

后端代码：

@WebServlet("/findUserServlet")
public class FindUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.获取id
        String id =request.getParameter("id");
        //2.调用Service查询
        UserService service = new UserServiceImpl();
        User user = service.findUserById(id);

        //3.将user存入request
        request.setAttribute("user",user);
        //4.转发到update.jsp
        request.getRequestDispatcher("/update.jsp").forward(request,response);



    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

@WebServlet("/updateUserServlet")
public class UpdateUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.设置编码
        request.setCharacterEncoding("utf-8");
        //2.获取map
        Map<String, String[]> map = request.getParameterMap();
        //3，封装对象
        User user =new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }

        //4.调用Service修改
        UserService service = new UserServiceImpl();
        service.updateUser(user);

        //跳转到查询所有Servlet
        response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

二、复杂功能

1.删除选中

可以勾选多条数据进行删除
前端代码：

<script>
 window.onload = function () {
            //给删除选中按钮添加的单击事件
            document.getElementById("delSelected").onclick = function () {
               if(confirm("您确定要删除选中条目吗？")){

                   var flag =false;
                   //判断是否有选中条目
                   var cbs = document.getElementsByName("uid");
                   for(var i =0; i<cbs.length;i++){
                      if(cbs[i].checked ) {
                          //有一个条目选中了
                          flag =true;
                          break;
                      }
                   }
                   if(flag){//所有条目被选中
                       //表单提交
                       document.getElementById("form").submit();
                   }

               }

            }
            //1.获取第一个id
            document.getElementById("firstCb").onclick = function () {
                //2.获取下边列表中所有的cb
                var cbs = document.getElementsByName("uid");
                //3.遍历
                for(var i =0; i<cbs.length;i++){
                    //设置这些cbs[i]的checked状态 = firstCb.checked
                    cbs[i].checked = this.checked;

                }
            }
        }

    </script>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">
        <form class="form-inline" action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" name="name" value="${condition.name[0]}" class="form-control" id="exampleInputName2" >
            </div>
            <div class="form-group">
                <label for="exampleInputName3">籍贯</label>
                <input type="text" name="address"  value="${condition.address[0]}" class="form-control" id="exampleInputName3" >
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="text" name="email" value="${condition.email[0]}" class="form-control" id="exampleInputEmail2" >
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>

    <div style="float: right; margin: 5px;">
        <a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a>
        <a class="btn btn-primary" href="javascript:void(0);"id="delSelected">删除选中</a>
    </div>
    <form id="form" action="${pageContext.request.contextPath}/delSelectedServlet" method="post">
        <table border="1" class="table table-bordered table-hover">
        <tr class="success">
            <th><input type="checkbox" id="firstCb"></th>
            <th>编号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>籍贯</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>

        <c:forEach items="${pb.list}" var="user" varStatus="s">
        <tr>
            <td><input type="checkbox" name="uid" value="${user.id}"></td>
            <td>${s.count}</td>
            <td>${user.name}</td>
            <td>${user.gender}</td>
            <td>${user.age}</td>
            <td>${user.address}</td>
            <td>${user.qq}</td>
            <td>${user.email}</td>
            <td><a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>&nbsp;
                <a class="btn btn -default btn-sm" href="javascript:deleteUser(${user.id});">删除</a></td>
        </tr>

        </c:forEach>

后端代码：

servlet代码：

@WebServlet("/delSelectedServlet")
public class DelSelectedServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //1.获取所有的id
        String[] ids = request.getParameterValues("uid");
        //调用service删除
        UserService service = new UserServiceImpl();
        service.delSelectedUser(ids);

        //3.跳转查询所有servlet
        response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

service代码:

 public void delSelectedUser(String[] ids) {
        if(ids != null && ids.length > 0){
            //1.遍历数组
            for(String id :ids){
                //2.调用dao删除
                dao.delete(Integer.parseInt(id));
        }

        }
    }

在这里插入图片描述

2.分页查询

将数据分页查询，可以减轻服务器的开销，提升了用户的体验。
在这里插入图片描述

先创建分页对象，pageBean实体类

public class PageBean<T> {
    private int totalCount;//总记录数
    private int totalPage;//总页码
    private List<T> list;//每页数据
    private int currentPage;//当前页码
    private int rows;//每页显示的记录数
    ...
    }

前端代码：

<div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <c:if test="${pb.currentPage == 1}">
                    <li class="disabled">
                </c:if>
                    <c:if test="${pb.currentPage != 1}">
                    <li>
                    </c:if>


                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage - 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>

                <c:forEach begin="1" end="${pb.totalPage}" var="i">
                    <c:if test="${pb.currentPage == i}">
                        <li class="active"><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a></li>
                    </c:if>

                    <c:if test="${pb.currentPage != i}">
                        <li><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a></li>
                    </c:if>

                </c:forEach>

                    <c:if test="${pb.currentPage == pb.totalPage}">
                        <li class="disabled">
                    </c:if>
                        <c:if test="${pb.currentPage != pb.totalPage}">
                        <li>
                        </c:if>

                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage + 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left:5px; ">
                    共${pb.totalCount}条记录，共${pb.totalPage}页
                </span>
            </ul>
        </nav>
    </div>

后端代码：
servlet：

@WebServlet("/findUserByPageServlet")
public class FindUserByPageServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");

        //1.获取参数
        String currentPage = request.getParameter("currentPage");//当前页码
        String rows = request.getParameter("rows");//每页显示条数

        if(currentPage == null || "".equals(currentPage) ){
            currentPage = "1";
        }
        if(rows == null || "".equals(rows)){
            rows = "5";
        }

        //获取条件查询参数
        Map<String, String[]> condition = request.getParameterMap();

        //2.调用service查询
        UserService service =new UserServiceImpl();
        PageBean<User> pb = service.findUserByPage(currentPage,rows,condition);

        System.out.println(pb);

        //3.将PageBean存入request
        request.setAttribute("pb",pb);
        request.setAttribute("condition",condition);//将查询条件存入request

        //4.转发到list.jsp
        request.getRequestDispatcher("/list.jsp").forward(request,response);


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

service:

  @Override
    public PageBean<User> findUserByPage(String _currentPage, String _rows, Map<String, String[]> condition) {

        int currentPage = Integer.parseInt(_currentPage);
        int rows = Integer.parseInt(_rows);


        if(currentPage <=0){
            currentPage = 1;
        }
        //1.创建空的PageBean对象
        PageBean<User> pb = new PageBean<User>();
        //2.调用dao查询总记录数
        int totalCount = dao.findTotalCount(condition);
        pb.setTotalCount(totalCount);
        //3.计算总页码
        int totalPage = totalCount % rows == 0 ? totalCount / rows : totalCount / rows + 1;
        pb.setTotalPage(totalPage);

        if (currentPage > totalPage) {
            currentPage = totalPage;
        }
        //4.设置参数
        pb.setCurrentPage(currentPage);
        pb.setRows(rows);

        //调用dao查询list集合
        //计算开始的记录索引
        int start = (currentPage - 1)*rows;
        List<User> list =dao.findByPage(start,rows,condition);
        pb.setList(list);

        return pb;
    }

3.复杂条件查询

在这里插入图片描述
前端代码：

<div style="float: left;">
        <form class="form-inline" action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" name="name" value="${condition.name[0]}" class="form-control" id="exampleInputName2" >
            </div>
            <div class="form-group">
                <label for="exampleInputName3">籍贯</label>
                <input type="text" name="address"  value="${condition.address[0]}" class="form-control" id="exampleInputName3" >
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="text" name="email" value="${condition.email[0]}" class="form-control" id="exampleInputEmail2" >
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>