基于设计模式的用户管理

基于DAO模式和MVC模式完成一个用户管理程序,包括用户注册、用户登录、浏览用户列表和删除用户等四个功能。
要求：1）JSP页面中不允许出现Java代码，使用标签实现显示逻辑
          2）HTTP请求发送给Servlet，由Servlet负责调用DAO类，并转发给JSP页面
          3）浏览用户列表页面要支持分页功能

DBCon.java类：与数据库admin表连接，有插入，删除等动作；

package db_admin;

import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBCon {
    private String dbDriver = "com.mysql.jdbc.Driver";
    private String dbUrl = "jdbc:mysql://localhost:3306/book?useUnicode=true&characterEncoding=utf-8";
    private String dbUser = "root";
    private String dbPwd = "123456";
    private Connection conn = null;

    public Connection getConnection() {
        try {
            Class.forName(dbDriver);
            conn = DriverManager.getConnection(dbUrl, dbUser, dbPwd);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }

    public ResultSet doQurey(String sql) {
        ResultSet rs = null;
        conn = this.getConnection();
        try {
            Statement stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return rs;
    }

    public int doUpdate(String sql) {
        int res = 0;
        conn = this.getConnection();
        try {
            Statement stmt = conn.createStatement();
            res = stmt.executeUpdate(sql);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return res;
    }

    public String checkUser(String username, String password) {
        boolean has_username = false;
        boolean password_correct = false;
        ResultSet rs = null;
        try {
            rs = doQurey("select * from admin");
        } catch (Exception e) {
            e.printStackTrace();
        }

        try {
            while (rs.next()) {
                String temp_username = rs.getString("username");
                String temp_password = rs.getString("password");
                if (username.equals(temp_username)) {
                    has_username = true;
                    if (password.equals(temp_password)) {
                        password_correct = true;

                        return "hasUserNameAndPasswordCorrect";

                    }

                    return "hasUserNameButPasswordInCorrect";

                }

            }

        } catch (SQLException e) {

            e.printStackTrace();

        }

        return "hasNoUserName";

    }

    public void close() throws SQLException {
        try {
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

LoginControl.java：Servlet类，做登录验证，查看用户是否存在，密码是否正确；

package servletLogin;

import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import db_admin.DBCon;

/**
 * Servlet implementation class LoginControl
 */
@WebServlet("/LoginControl")
public class LoginControl extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginControl() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        DBCon dbc = new DBCon();
        String result = dbc.checkUser(username, password);
        if (result.equals("hasUserNameAndPasswordCorrect")) {
            System.out.println("用户名及密码正确");
            RequestDispatcher rd = request.getRequestDispatcher("index.jsp");
            rd.forward(request, response);
        } else if (result.equals("hasUserNameButPasswordInCorrect")) {
            System.out.println("密码不正确");
            RequestDispatcher rd = request.getRequestDispatcher("error.jsp");
            rd.forward(request, response);
        } else if (result.equals("hasNoUserName")) {
            System.out.println("该用户不存在");
            RequestDispatcher rd = request.getRequestDispatcher("error2.jsp");
            rd.forward(request, response);
        }


    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

regist.jsp:注册页面；

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>注册页面</title>
<style>
@charset "utf-8";
#frm {
    padding: 20px;
    margin-top: 10px;
    height: 1000px;
    background-color: #F0FFFF;
}
#main{
margin-top:30px;
margin-left:200px;
    background-color: #FFDAB9;
    border:1px solid;
    padding:10px 40px; 
    300px;
    overflow:auto;
    text-align:center;
}
.divcls {
    border-bottom: 1px dashed blue;
    margin-bottom: 10pt;
    padding-bottom: 10pt;
}
#mytop{
    text-align:left;
      margin-bottom:10pt;
      font-size:15pt;
    }
#mytop a{
font-size:10pt;
color:bule;
}
#mytop span{
    font-size:10px;
    font-weight:bolder;
    }
.info {
    margin-left: 25%;
    padding: 14px 16px;
    height: 1000px;
}
.myrow {
    margin: 10pt 0;
}
.myrow label {
    display: block;
     100pt;
    font-weight: bolder;
}
.myrow note {
    font-size: 10px;
    font-weight: bloder;
}
.noignore {
    color: red;
}
.submit {
 style:100%;
    text-align: center;
}
.agree {
    color: red;
    font-size: 15px;
}
</style>
<script type="text/javascript">
function nme(){
    var result = true;
    var nameDOM = document.getElementById('uname').value;
    if (nameDOM == '') {
        document.getElementById('name').innerHTML = '<span style="color:red;">用户名不能为空!</span>';
        result = false;
    }else {
        document.getElementById('name').innerHTML = '<span style="color:green;">正确!</span>';
        result = true;
    }

    return result;
}
/*密码验证*/
function Password(){
    var result = true;
    var pwdDOM = document.getElementById('upwd').value;
    if (pwdDOM == ''){
        document.getElementById('pwd').innerHTML =  '<span style="color:red;">密码不能为空!</span>';
        result = false;
    }else {
        document.getElementById('pwd').innerHTML = '<span style="color:green;">正确!</span>';
        result = true;
    }
    return result;
}
/*确认密码验证*/
function rePassword(){
    var result = true;
    var pwdDOM = document.getElementById('upwd').value;
    var repwdDOM = document.getElementById('reupwd').value;
    if (repwdDOM == ''){
        document.getElementById('repwd').innerHTML =  '<span style="color:red;">此项不能为空!</span>';
        result = false;
    }else {
        document.getElementById('repwd').innerHTML = '<span style="color:green;">正确!</span>';
        result = true;
    }
    return result;
}
function Rabbit(){
    var Rabit = new Array();
    Rabit[0] = nme();
    Rabit[1] = Password();
    return Rabit;

}
function myFunction(){
    var w = new Array();
    w = Rabbit();
    var a = 0;
    var s = 1;
    for (var i = 0; i < 2; i++) {
        if(w[i]==true){
            a++;console.warn(a);
        }
        console.warn(w[i]);
    }

    if (a == 2) {
        alert("注册成功");
    }
    else{
        alert('请按规定输入完整的注册资料！');
        var Rabit;
        Rabit = Password();
        if (Rabit == false) {
            var passwordfocus = document.getElementById('password');
            passwordfocus.focus();
        }
        Rabit = nme();
        if (Rabit == false) {
            var codefocus = document.getElementById('name');
            codefocus.focus();
        }
    }
}
</script>
</head>
<body>
<form id="frm" action="do_insert.jsp" method="post">
  <div id="mytop" class="divcls">用户注册:
  <a href="login.jsp">已注册，点击登录</a>
  </div>
  <div id="main">
  <div class="myrow">
    <label for="uname">用户名&nbsp;：</label>
    <input type="text" id="uname" name="username" onClick="nme()"/>
    <span class="noignore">*</span> <span class="note" id="name">必填</span> </div>
  <div class="myrow">
    <label for="upwd">密&nbsp;&nbsp;&nbsp;码：</label>
    <input type="password" id="upwd" name="password" onClick="Password()"/>
    <span class="noignore">*</span> <span class="note" id="pwd">必填</span> </div>
  <div class="submit"> 
  <input id="mysubmit" type="submit" value="确认注册" onClick="myFunction()"/>
  <input id="mysubmit" type="reset" value="重置"/>
  </div>
   </div>
  </form>
</body>
</html>

do_insert.jsp:将输入的用户名与密码插入到数据库的admin表中；

<%@ page import="db_admin.DBCon,java.sql.*" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>添加用户</title>
</head>
<body>
<%
response.setCharacterEncoding("utf-8");
String username = request.getParameter("username");
String password = request.getParameter("password");
DBCon dbc = new DBCon();
String sql = "insert into admin(username,password)values('"+ username +"','"+ password +"')";
int res = dbc.doUpdate(sql);
if(res>0){
    out.print("<script>alert('注册成功，单击跳转到登录页面！')</script>");
    response.setHeader("refresh", "1;url='login.jsp'");
}else{
    out.print("<script>alert('注册失败，单击跳转到注册页面！')</script>");
    response.sendRedirect("regist.jsp");
}
%>
</body>
</html>

login.jsp:登录页面；

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>登录页面</title>
<style>
@charset "utf-8";
#frm {
    padding: 20px;
    margin-top: 10px;
    height: 1000px;
    background-color: #F0FFFF;
}
#main{
margin-top:30px;
margin-left:200px;
    background-color: #FFDAB9;
    border:1px solid;
    padding:10px 40px; 
    300px;
    overflow:auto;
    text-align:center;
}
.divcls {
    border-bottom: 1px dashed blue;
    margin-bottom: 10pt;
    padding-bottom: 10pt;
}
#mytop{
    text-align:left;
      margin-bottom:10pt;
      font-size:15pt;
    }
#mytop a{
font-size:10pt;
}
#mytop span{
    font-size:10px;
    font-weight:bolder;
    }
.myrow {
    margin: 10pt 0;
}
.myrow label {
    display: block;
     100pt;
    font-weight: bolder;`
}
.myrow note {
    font-size: 10px;
    font-weight: bloder;
}
.noignore {
    color: red;
}
.submit {
 style:100%;
    text-align: center;
}
.agree {
    color: red;
    font-size: 15px;
}
</style>
</head>
<body>
<form id="frm" action="LoginControl" method="post">

  <div id="mytop" class="divcls">用户登录:
  <a href="regist.jsp">未注册，点击注册</a>
  </div>
  <div id="main">
  <div class="myrow">
    <label for="uname">用户名&nbsp;：</label>
    <input type="text" id="uname" name="username" onClick="nme()"/>
</div>
  <div class="myrow">
    <label for="upwd">密&nbsp;&nbsp;&nbsp;码：</label>
    <input type="password" id="upwd" name="password" onClick="Password()"/>
</div>
  <div class="submit"> 
  <input id="mysubmit" type="submit" value="登录"/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
  <input id="mysubmit" type="reset" value="重置"/>
  </div>
  </div>
  </form>
</body>
</html>

pager.jsp:分页显示admin中的数据；

<%@page import="java.sql.*,db_admin.*"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>分页显示</title>
<style type="text/css">
body{
    background-color: #FFDAB9;
}
body.table{
margin-top:30px;
margin-left:200px;
}
</style>
</head>
<body>
    <%
        //总的页面数
        int pageCount = 0;
        //每页显示的记录数
        int pageSize = 5;
        //当前页面
        int currentP = 1;
        //表中的记录数
        int totalCount = 5;
        //数据库的连接
        DBCon dbc = new DBCon();
        //表中总记录数
        String sql = "select count(*) as t from admin";
        ResultSet rs = dbc.doQurey(sql);
        if (rs.next())
            totalCount = rs.getInt("t");
        //根据总的记录数来计算页面数
        if (totalCount / pageSize == 0)
            pageCount = (totalCount / pageSize);
        else
            pageCount = (totalCount / pageSize) + 1;
        //获得分页条上的当前页码
        String pStr = request.getParameter("p");
        if (pStr == null)
            pStr = "1";
        currentP = Integer.parseInt(pStr);
        //如果当前页大于总的页面数，当前页面赋值为总的页面数
        if (currentP > pageCount)
            currentP = pageCount;
        //如果当前页小于0，重置为第一页
        if (currentP < 0)
            currentP = 1;
        //分页查询，MySQL分页查询关键字limit，注意limit后有空格
        sql = "select * from admin limit " + (currentP - 1) * pageSize + "," + pageSize;
        rs = dbc.doQurey(sql);
    %>
    <table border="1">
            <tr>
        <th>id</th>
        <th>用户名</th>
        <th>密码</th>
        <th>功能</th>
        </tr>
        <%
            while (rs.next()) {
        %>

        <tr>
            <td><%= rs.getInt("id") %></td>
            <td><%= rs.getString("username") %></td>
            <td><%= rs.getString("password") %></td>
            <td><a href="do_edit.jsp?id=<%= rs.getInt("id")%>">编辑</a>
            <a href="do_delete.jsp?id=<%= rs.getInt("id")%>">删除</a>
            </td>
        </tr>
        <%
            }
        %>
    </table>
    <%
        if (currentP > 1) {
    %>
    <a href="pager.jsp?p=1">第一页</a>
    <a href="pager.jsp?p=<%= currentP - 1 %>">上一页</a>
    <%
        }
    %>
    <%
        if (currentP <= pageCount) {
    %>
    <a href="pager.jsp?p=<%= currentP + 1 %>">下一页</a>
    <a href="pager.jsp?p=<%= pageCount %>">最后一页</a>
    <%
        }
    %>
</body>
</html>