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摘要:

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Servlet与Jsp的结合使用实现信息管理系统二


PS:前面说了抽取框架的搭建,接着就要我们开始进入网址的时候就要查到全部信息并显示在首页,我们用到的MySql数据库,具体步骤是:

  • 创建数据库,创建表,添加信息
  • 项目中调入mysql的jar包 mysql-connector-java-5.1.18-bin.jar
  • 单独一个类写JDBC连接数据库
  1. 查询的Sql语句及方法
  2. 删除sql语句及方法
  3. 增加sql语句及方法
  4. 修改sql语句及方法
  • xml配置文件的设置
  • mainservlet中写相应操作

1:创建数据库,创建表,添加信息

2:项目中调入mysql的jar包 mysql-connector-java-5.1.18-bin.jar

自行导入即可

3:单独一个类写JDBC连接数据库

 /**
     * 开启数据库连接
     * */
    public void getConnect() {
        String driver = "com.mysql.jdbc.Driver";
// URL指向要访问的数据库名,设置编码
        String url = "jdbc:mysql://127.0.0.1:3306/ceshi1?useUnicode=true&characterEncoding=utf-8";
// MySQL配置时的用户名
        String user = "root";
// Java连接MySQL配置时的密码
        String password = "root";
        try {
// 加载驱动程序
            Class.forName(driver);
// 连续数据库
            conn = DriverManager.getConnection(url, user, password);
            if (!conn.isClosed())
                System.out.println("Succeeded connecting to the Database!");
// statement用来执行SQL语句
            statement = conn.createStatement();
// 要执行的SQL语句
            String sql = "select * from information";
        } catch (Exception e) {
            System.out.println("连接失败");
        }
    }

    /**
     * 断开数据库连接*/
    public void disConnect() throws SQLException {
        if(conn!=null){
            conn.close();
            statement.close();
        }
    }

 下面是增删查改,查询数据和查询单条数据都是返回一个list集合,原本是可以写成一个方法的,但为了清楚显示,就单独写了。在这之前呢,要先写一个model类

public class Information {
    String name,banji,qq,shouji,zhuangtai;
    int id,age;


    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getBanji() {
        return banji;
    }

    public void setBanji(String banji) {
        this.banji = banji;
    }

    public String getQq() {
        return qq;
    }

    public void setQq(String qq) {
        this.qq = qq;
    }

    public String getShouji() {
        return shouji;
    }

    public void setShouji(String shouji) {
        this.shouji = shouji;
    }

    public String getZhuangtai() {
        return zhuangtai;
    }

    public void setZhuangtai(String zhuangtai) {
        this.zhuangtai = zhuangtai;
    }
}

 

/**
     * 查询全部数据,返回list集合
     * String sql = "select * from information";
     */
    public List<Information> queryAllData() throws SQLException {
        List<Information> list = new ArrayList<Information>();
        String sql = "select * from information";
        ResultSet rs = statement.executeQuery(sql);
        while (rs.next()) {
            System.out.print(rs.getInt("id"));
            information = new Information();
            information.setId(rs.getInt("id"));
            information.setName(rs.getString("name"));
            information.setAge(rs.getInt("age"));
            information.setBanji(rs.getString("banji"));
            information.setQq(rs.getString("qq"));
            information.setShouji(rs.getString("shouji"));
            information.setZhuangtai(rs.getString("zhuangtai"));
            list.add(information);
        }


        return list;
    }

    /***
     *插入数据 
     */

    public int addData(String sql) {
        int a = 0;
        try {
            a = statement.executeUpdate(sql);
            System.out.print("插入成功");
        } catch (SQLException e) {
            System.out.print("插入失败");
            e.printStackTrace();
        }
        return a;
    }

    /***
     *删除数据 
     */
    public void deleteData(String sql) {
        try {
            statement.executeUpdate(sql);
            System.out.print("删除成功");
        } catch (SQLException e) {
            System.out.print("删除失败");
            e.printStackTrace();
        }
    }

    /**
     * 查询单条数据,返回一个list集合,为了是在用户修改的时候,把数据带到指定页面
     */
    public List<Information> updataData1(String sql) {
        try {
            list1 = new ArrayList<Information>();
            ResultSet rs = statement.executeQuery(sql);
            while (rs.next()) {

                information = new Information();
                information.setId(rs.getInt("id"));
                information.setName(rs.getString("name"));
                information.setAge(rs.getInt("age"));
                information.setBanji(rs.getString("banji"));
                information.setQq(rs.getString("qq"));
                information.setShouji(rs.getString("shouji"));
                information.setZhuangtai(rs.getString("zhuangtai"));
                list1.add(information);
            }
            System.out.print("查成功");
        } catch (SQLException e) {
            System.out.print("查失败");
            e.printStackTrace();
        }
        return list1;
    }

    /**
     * 更改数据,如果成功返回1
     */
    public void updataData2(String sql) {
        try {
            int num = statement.executeUpdate(sql);
            System.out.print("更改成功");

        } catch (SQLException e) {
            System.out.print("更改失败");
            e.printStackTrace();
        }
    }

4:xml配置文件设置拦截,只要是后面带.do的都拦截。

 <servlet-mapping>
        <servlet-name>mainservlet</servlet-name>
       <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>mainservlet</servlet-name>
        <servlet-class>control.MainServlet</servlet-class>
    </servlet>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

 

5:mainservlet中写相应操作

5.1在网页加载的时候就调用数据库查询全部数据,并返回到首页,首先要对页面编码设置

     response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");

 然后要获取地址栏中的url地址,该地址是8080后面的字符串

String str = request.getRequestURI();

 拦截字符串进行equals比较,

//查询全部:
     connecDatabase();//连接数据库 if (str.equals("/MyTest.do")) { queryAllData(request, response); }

 queryAllData(request,response)方法,把获取到的数据转发到指定jsp

private void queryAllData(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        listAll = new ArrayList<>();

        try {
            listAll = daoConnection.queryAllData();
            daoConnection.disConnect();
            request.getSession().setAttribute("listAll", listAll);
            request.getRequestDispatcher("index.jsp").forward(request, response);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
/**
     * 连接数据库
     * */
    public void connecDatabase(){
        daoConnection = new DaoConnection();
        daoConnection.getConnect();
    }

首页代码:其中获取servlet传过来的值是forEach

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
    <link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
    <script src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>

<p>

    <a href="addData.jsp" class="btn btn-primary btn-lg" role="button">添加数据</a>
</p>

<!--项目列表 主页-->
<table class="table table-striped" style="width: 100%">
    <caption>信息全部详情</caption>

    <thead>
    <tr>
        <th>ID</th>
        <th>姓名</th>
        <th>年龄</th>
        <th>班级</th>
        <th>QQ</th>
        <th>手机</th>
        <th>状态</th>
        <th>操作</th>
    </tr>
    </thead>
    <tbody>
    <c:forEach items="${listAll}" var="listall">
        <tr>
            <td>${listall.id}</td>
            <td>${listall.name}</td>
            <td>${listall.age}</td>
            <td>${listall.banji}</td>
            <td>${listall.qq}</td>
            <td>${listall.shouji}</td>
            <td>${listall.zhuangtai}</td>
            <td><a href="/bianji.do?id=${listall.id}" id="bianji" >编辑</a>/<a href="/delete.do?id=${listall.id}" >删除</a></td>
        </tr>
    </c:forEach>
    </tbody>
</table>


</div>
</body>
</html>

效果:

 

5.2添加数据

添加中,主要是ajax回调,$("#addform").serialize()可以从上往下找到表格里的值并作为数据发送给servlet,回调成功后会弹出一个友好提示框再返回到servlet中,是layui.js,去官网上直接下载即可,不过要注意的是,在form表单中,提交按钮type不能是submit,只能是button,否则不能用(一闪而过)。

<script >
    function tijiao() {
//        alert("ssss");
        var AjaxURL = "/adddata.do";
//        alert($("#addform").serialize());
        $.ajax({
            type: "POST",
            dataType: "html",
            url: AjaxURL,
            data: $("#addform").serialize(),
            success: function (result) {
                var strresult = result;
                layer.msg("插入成功,2秒返回主页", {
                    time: 2000 //2秒关闭(如果不配置,默认是3秒)
                }, function(){
                    location.href="/homepage.do";
                });
            },
            error: function (data) {
                layer.open({
                    title: "插入提示"
                    ,content: "插入失败"
                });
            }
        })
    }
</script>

 页面代码:<td><a href="/bianji.do?id=${listall.id}" id="bianji" >编辑</a>/<a href="/delete.do?id=${listall.id}" >删除</a></td>这里面可以直接对编辑,删除进行处理(在跳转到servlet中处理)。

<%--
  Created by IntelliJ IDEA.
  User: liuzhitong
  Date: 17/12/2
  Time: 下午8:45
  To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
    <script src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
    <link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
    <script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
    <script src="layui/layui.all.js"></script>
</head>
<body>
<caption>增加信息,(*为必填)</caption>
<form class="form-horizontal" role="form"  accept-charset="utf-8" id="addform" >
    <div class="form-group">
        <label for="id_id" class="col-sm-2 control-label">(数字)*ID:</label>
        <div class="col-sm-10">
            <input type="number" class="form-control" name="dataid" id="id_id" placeholder="请输入ID">
        </div>
    </div>
    <div class="form-group">
        <label for="id_name" class="col-sm-2 control-label">*姓名:</label>
        <div class="col-sm-10">
            <input type="text" name="dataname" class="form-control" id="id_name" placeholder="请输入名字">
        </div>
    </div>
    <div class="form-group">
        <label for="id_age" class="col-sm-2 control-label">(数字)年龄:</label>
        <div class="col-sm-10">
            <input type="number" name="dataage" class="form-control" id="id_age" placeholder="请输入年龄">
        </div>
    </div>
    <div class="form-group">
        <label for="id_banji" class="col-sm-2 control-label">班级:</label>
        <div class="col-sm-10">
            <input type="text" name="databanji" class="form-control" id="id_banji" placeholder="请输入班级">
        </div>
    </div>
    <div class="form-group">
        <label for="id_qq" class="col-sm-2 control-label">QQ:</label>
        <div class="col-sm-10">
            <input type="text" name="dataqq" class="form-control" id="id_qq" placeholder="请输入QQ">
        </div>
    </div>
    <div class="form-group">
        <label for="id_shouji" class="col-sm-2 control-label">手机:</label>
        <div class="col-sm-10">
            <input type="text" name="datashouji" class="form-control" id="id_shouji" placeholder="请输入手机">
        </div>
    </div>
    <div class="form-group">
        <label for="id_zhuangtai" class="col-sm-2 control-label">状态:</label>
        <div class="col-sm-10">
            <input type="text" name="datazhuangtai" class="form-control" id="id_zhuangtai" placeholder="请输入状态">
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="button" class="btn btn-default"   onclick="tijiao()" >保存</button>
           <a href="homepage.jsp" class="btn btn-default" role="button">返回</a>
        </div>
    </div>
</form>
</body>

<script >
    function tijiao() {
//        alert("ssss");
        var AjaxURL = "/adddata.do";
//        alert($("#addform").serialize());
        $.ajax({
            type: "POST",
            dataType: "html",
            url: AjaxURL,
            data: $("#addform").serialize(),
            success: function (result) {
                var strresult = result;
//                alert("插入成功");
                layer.msg("插入成功,2秒返回主页", {

                    time: 2000 //2秒关闭(如果不配置,默认是3秒)
                }, function(){
                    location.href="/homepage.do";
                });
            },
            error: function (data) {
//                alert("error:" + data.responseText);
                layer.open({
                    title: "插入提示"
                    ,content: "插入失败"
                });
            }
        })
    }
</script>
</html>

 MainServlet.java中对接收的数据进行处理,接收数据直接用String name = request.getParameter("dataname");

else if(str.equals("/adddata.do")){
            addServletData(request, response);
        }

 

private void addServletData(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String id=request.getParameter("dataid");
        System.out.print("ceshi---"+id);
        String name = request.getParameter("dataname");
        String banji = request.getParameter("databanji");
        String dataqq = request.getParameter("dataqq");
        String datashouji = request.getParameter("datashouji");
        String datazhuangtai = request.getParameter("datazhuangtai");
        int age =Integer.parseInt(request.getParameter("dataage"));
        if (name.equals("") || id.equals("") ) {
        } else {
            String sql = "INSERT INTO information VALUES("" + id + "","" + name + ""," + age + ","" + banji + "","" + dataqq + "","" + datashouji + "","" + datazhuangtai + "")";
            panduan = daoConnection.addData(sql);
        }
        response.getWriter().write("yue");

    }

 到这里就插入成功了。

5.3编辑数据

在编辑jsp中也有ajax回调,用法和插入是一样的。当用户点击编辑的时候,首先url会带着该条数据的ID进入MainServlet.java进行查找该id的数据并且再带着数据list返回到编辑页面,在编辑页面点击保存按钮的时候再次进入servlet处理,而不是点击就直接进入编辑页面。

<a href="/bianji.do?id=${listall.id}" id="bianji" >编辑</a>/<a href="/delete.do?id=${listall.id}" >删除</a></td>

处理代码:

else if(str.equals("/bianji.do")){
            bianjiData(request,response);//仅仅是把之前的数据待到编辑.jsp页面。
        }

 

private void bianjiData(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String id=request.getParameter("id");
        System.out.print("------"+id);
        String chaSql="SELECT * FROM information WHERE id = ""+id+""";
        List<Information> listDan=daoConnection.updataData1(chaSql);
        request.getSession().setAttribute("listDan",listDan);
        request.getRequestDispatcher("bianji.jsp").forward(request,response);
    } 

bianji.jsp点击保存按钮处理

else if(str.equals("/update.do")){
            updateData(request,response);
        }

 

private void updateData(HttpServletRequest request, HttpServletResponse response) {
        String id=request.getParameter("dataid");
        System.out.print("ceshi---"+id);
        String name = request.getParameter("dataname");
        String banji = request.getParameter("databanji");
        String dataqq = request.getParameter("dataqq");
        String datashouji = request.getParameter("datashouji");
        String datazhuangtai = request.getParameter("datazhuangtai");
        int age =Integer.parseInt(request.getParameter("dataage"));
        if (name.equals("") || id.equals("") ) {
        } else {
           String sql = "UPDATE information set age="+age + ",banji=""+banji+"",qq=""+dataqq+"",shouji=""+datashouji+"",zhuangtai=""+datazhuangtai+"" where id=""+id+""";
            daoConnection.updataData2(sql);
            flushpage(request,response);
        }
    }
 private void flushpage(HttpServletRequest request, HttpServletResponse response) {
listAll = new ArrayList<>();
try {
listAll = daoConnection.queryAllData();
request.getSession().setAttribute("listAll", listAll);
request.getRequestDispatcher("homepage.jsp").forward(request, response);
} catch (SQLException e) {
e.printStackTrace();
} catch (ServletException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

 

编辑页面jsp全部代码:

<%--
  Created by IntelliJ IDEA.
  User: liuzhitong
  Date: 17/12/2
  Time: 下午8:45
  To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
    <%--<script src="http://cdn.static.runoob.com/libs/jquery/2.2.1/jquery.min.js"></script>--%>
    <%--<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>--%>
    <script src="js/jquery.min.js"></script>

    <link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
    <script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script src="layui/layui.all.js"></script>
</head>
<body>
<caption>编辑页面,(*为必填)</caption>
<form class="form-horizontal" role="form"  accept-charset="utf-8" id="addform" >
<c:forEach items="${listDan}" var="listdan">
    <div class="form-group">
        <label for="id_id" class="col-sm-2 control-label">(数字)*ID:</label>
        <div class="col-sm-10">
            <input type="number" readonly="true" class="form-control" name="dataid" value="${listdan.id}" id="id_id" placeholder="请输入ID">
        </div>
    </div>
    <div class="form-group">
        <label for="id_name" class="col-sm-2 control-label">*姓名:</label>
        <div class="col-sm-10">
            <input type="text" readonly="true" name="dataname" class="form-control" value="${listdan.name}" id="id_name" placeholder="请输入名字">
        </div>
    </div>
    <div class="form-group">
        <label for="id_age" class="col-sm-2 control-label">(数字)年龄:</label>
        <div class="col-sm-10">
            <input type="number" name="dataage" class="form-control" value="${listdan.age}" id="id_age" placeholder="请输入年龄">
        </div>
    </div>
    <div class="form-group">
        <label for="id_banji" class="col-sm-2 control-label">班级:</label>
        <div class="col-sm-10">
            <input type="text" name="databanji" class="form-control" value="${listdan.banji}" id="id_banji" placeholder="请输入班级">
        </div>
    </div>
    <div class="form-group">
        <label for="id_qq" class="col-sm-2 control-label">QQ:</label>
        <div class="col-sm-10">
            <input type="text" name="dataqq" class="form-control" value="${listdan.qq}" id="id_qq" placeholder="请输入QQ">
        </div>
    </div>
    <div class="form-group">
        <label for="id_shouji" class="col-sm-2 control-label">手机:</label>
        <div class="col-sm-10">
            <input type="text" name="datashouji" class="form-control" value="${listdan.shouji}" id="id_shouji" placeholder="请输入手机">
        </div>
    </div>
    <div class="form-group">
        <label for="id_zhuangtai" class="col-sm-2 control-label">状态:</label>
        <div class="col-sm-10">
            <input type="text" name="datazhuangtai" class="form-control" value="${listdan.zhuangtai}" id="id_zhuangtai" placeholder="请输入状态">
        </div>
    </div>


    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="button" class="btn btn-default"   onclick="tijiao()" >保存</button>
            <a href="homepage.jsp" class="btn btn-default" role="button">返回</a>
        </div>
    </div>
</c:forEach>


</form>
</body>

<script >
    function tijiao() {
        var AjaxURL = "/update.do";
        $.ajax({
            type: "POST",
            dataType: "html",
            url: AjaxURL,
            data: $("#addform").serialize(),
            success: function (result) {
                var strresult = result;
                layer.alert("修改成功", function(index){
                    layer.close(index);
                    location.href="/homepage.do";
                });
            },
            error: function (data) {
//                alert("error:" + data.responseText);
                layer.alert("修改失败", function(index){
                    layer.close(index);

                });
            }
        })
    }
</script>
</html>

 5.4:删除一行数据,和编辑一样也是先带着id进入servlet处理,

else if(str.equals("/delete.do")){
            deleteData(request,response, id);
        }

 

    private void deleteData(HttpServletRequest request, HttpServletResponse response, String ID) throws ServletException, IOException {

        String deleteSql = "DELETE FROM information WHERE id = "" + ID + """;

        daoConnection.deleteData(deleteSql);

        flushpage(request, response);
    }

 到此,增删查改就全部写完了,上面代码看似复杂,其实没一个功能都是独立的,也就是只写一个增加功能,也是可以运行的。哦对了,还有一个wendang.jsp,这个大家可以仿着来。

总效果图:

 

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发布时间:2019-04-25 01:43:15

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