MVC模式

1.MVC是一种开发模式

Model-View-Controller
View 视图层
JSP,JS框架
实现用户界面
Controller 控制层
Servlet,Filter
实现接收请求和返回响应
Model 模型层
实体类，DAO
实现数据库访问和业务逻辑

2.创建的包

.

3.创建的jsp文件以及导入的数据库jar包

4.模型层的实体类，DAO类以及业务逻辑类

package com.hanqi.entity;
//实体类
public class T_BALANCE {
    private String card_ID;
    private String user_ID;
    private String user_Name;
    private String password;
    private double T_BALANCE;
    private String state;
    private String create_time;
    public String getCard_ID() {
        return card_ID;
    }
    public void setCard_ID(String card_ID) {
        this.card_ID = card_ID;
    }
    public String getUser_ID() {
        return user_ID;
    }
    public void setUser_ID(String user_ID) {
        this.user_ID = user_ID;
    }
    public String getUser_Name() {
        return user_Name;
    }
    public void setUser_Name(String user_Name) {
        this.user_Name = user_Name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    
    public String getState() {
        return state;
    }
    public void setState(String state) {
        this.state = state;
    }
    public String getCreate_time() {
        return create_time;
    }
    public void setCreate_time(String create_time) {
        this.create_time = create_time;
    }
    
    public T_BALANCE(String user_ID, String user_Name, String password, String state) {
        super();
        this.user_ID = user_ID;
        this.user_Name = user_Name;
        this.password = password;
        this.state = state;
    }
    public double getT_BALANCE() {
        return T_BALANCE;
    }
    public void setT_BALANCE(double t_BALANCE) {
        T_BALANCE = t_BALANCE;
    }
    @Override
    public String toString() {
        return "T_BALANCE [card_ID=" + card_ID + ", user_ID=" + user_ID + ", user_Name=" + user_Name + ", password="
                + password + ", T_BALANCE=" + T_BALANCE + ", state=" + state + ", create_time=" + create_time + "]";
    }
    public T_BALANCE() {
        super();
        // TODO Auto-generated constructor stub
    }
    

}

package com.hanqi.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.hanqi.entity.T_BALANCE;
import com.hanqi.utility.DBHepler;


//数据库操作类
public class T_BALANCEDAO {

    // 查
    // 单条查询
    public T_BALANCE getT_BALANCE(String cardid) {
        T_BALANCE rtn = null;
        // 查询
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try {
            conn = DBHepler.getDBHepler().getConnection();
            String sql = "select * from T_BALANCE where card_id=?";
            ps = conn.prepareStatement(sql);
            ps.setString(1, cardid);
            rs = ps.executeQuery();
            if (rs.next()) {
                rtn = new T_BALANCE();

                rtn.setCard_ID(cardid);
                rtn.setT_BALANCE(rs.getDouble("T_BALANCE"));
                rtn.setCreate_time(rs.getString("create_time"));
                rtn.setPassword(rs.getString("password"));
                rtn.setState(rs.getString("state"));
                rtn.setUser_ID(rs.getString("user_id"));
                rtn.setUser_Name(rs.getString("user_name"));

            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                ps.close();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            try {
                rs.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return rtn;
        
    }
    //查询全部数据
        public List<T_BALANCE>getAll()
        {
            List<T_BALANCE> rtn =new  ArrayList<>();
            Connection conn = null;
            PreparedStatement ps = null;
            ResultSet rs = null;
            try {
                conn = DBHepler.getDBHepler().getConnection();
                String sql = "select * from T_BALANCE";
                ps = conn.prepareStatement(sql);
                rs = ps.executeQuery();
                while (rs.next()) {
                    T_BALANCE tb = new T_BALANCE();

                    tb.setCard_ID(rs.getString("card_id"));
                    tb.setT_BALANCE(rs.getDouble("T_BALANCE"));
                    tb.setCreate_time(rs.getString("create_time"));
                    tb.setPassword(rs.getString("password"));
                    tb.setState(rs.getString("state"));
                    tb.setUser_ID(rs.getString("user_id"));
                    tb.setUser_Name(rs.getString("user_name"));
                    rtn.add(tb);
                }

            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                try {
                    ps.close();
                } catch (SQLException e1) {
                    e1.printStackTrace();
                }
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                try {
                    rs.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            return rtn;
        }
    // 增
    //使用实体类接收数据
    public int insertBankCard(T_BALANCE tb)
    {
        int rtn = 0;
        Connection conn = null;
        PreparedStatement ps = null;
    
        try {
            conn = DBHepler.getDBHepler().getConnection();
            String sql = "insert into T_BALANCE(card_id,user_id,user_name,password,t_balance,create_time,state) values(?,?,?,?,?,?,?)";
            ps = conn.prepareStatement(sql);
            ps.setString(1, tb.getCard_ID());
            ps.setString(2, tb.getUser_ID());
            ps.setString(3, tb.getUser_Name());
            ps.setDouble(4, tb.getT_BALANCE());
            ps.setString(5, tb.getPassword());
            ps.setString(6, tb.getCreate_time());
            ps.setString(7, tb.getState());
            
            //执行插入数据
            rtn =ps.executeUpdate();
            //时间戳
            //Timestamp ts =new Timestamp(tb.getCreate_time())
            //表示精确时间
            //ps.setTimestamp(6, ts);
            
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                ps.close();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            
            }
        
        return rtn;
    }
    // 改
    public int updateBankCard(T_BALANCE tb)
    {
        int rtn=0;
        Connection conn = null;
        PreparedStatement ps = null;
    
        try {
            conn = DBHepler.getDBHepler().getConnection();
            String sql ="update T_BALANCE set user_id=?,"
                    + "user_name=?, t_balance=? ,password=?, "
                    + "create_time=? ,state=? where card_id=?";
            ps = conn.prepareStatement(sql);
            ps.setString(1, tb.getUser_ID());
            ps.setString(2, tb.getUser_Name());
            ps.setDouble(3, tb.getT_BALANCE());
            ps.setString(4, tb.getPassword());
            ps.setString(5, tb.getCreate_time());
            ps.setString(6, tb.getState());
            ps.setString(7, tb.getCard_ID());
            //执行插入数据
            rtn =ps.executeUpdate();
            //时间戳
            //Timestamp ts =new Timestamp(tb.getCreate_time())
            //表示精确时间
            //ps.setTimestamp(6, ts);
            
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                ps.close();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            
            }
        return rtn;
    } 
    // 删除
    public int deleteBankCard(String cardid)
    {
        int rtn=0;
        Connection conn = null;
        PreparedStatement ps = null;
    
        try {
                conn = DBHepler.getDBHepler().getConnection();
                String sql = "delete T_BALANCE where card_id=?";
                ps = conn.prepareStatement(sql);
                ps.setString(1, cardid);
                rtn = ps.executeUpdate();
            
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
            try {
                ps.close();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        
        }
        return rtn;
    }
}

package com.hanqi.Service;

import java.util.List;

import com.hanqi.dao.T_BALANCEDAO;
import com.hanqi.entity.T_BALANCE;

//业务逻辑类
public class BankCardService {
 
    //取单条数据
    public T_BALANCE getT_BALANCE(String cardid)
    {
        return new T_BALANCEDAO().getT_BALANCE(cardid);
    }
    
    //验证登录方法
    
    public T_BALANCE CheckLogin(String cardid,String password)
    
    {
        T_BALANCE rtn=null;
        
        //得到卡信息
    T_BALANCE tb=new T_BALANCEDAO().getT_BALANCE(cardid);
    System.out.println(tb);
    if(tb!=null)
    {
        //验证数据有效性
        if(tb.getCard_ID().equals(cardid)
           &&tb.getPassword().equals(password))
        {
            rtn =tb;
        }
    }
        return rtn;
    }
    //添加数据的方法
    public boolean addBankCard(T_BALANCE tb)
    {
        boolean rtn = false;
        //生成cardid
        String cardid =((int)(Math.random()*1000000)+"000000").substring(0,6);
        tb.setT_BALANCE(0);
        tb.setCreate_time("2011-11-22");
        tb.setCard_ID(cardid);
        //调用dao.保存数据
        rtn=new T_BALANCEDAO().insertBankCard(tb)==1;
        
        return rtn;
    
    }
    public List<T_BALANCE>getAllT_BALANCE()
    {
        return new T_BALANCEDAO().getAll();
    }
    //删除
    public void removeBankCard(String cardid) throws Exception
    {
        //过滤不允许删除的数据
        if(!cardid.equals("459333")){
        new T_BALANCEDAO().deleteBankCard(cardid);
        }
        else
        {
            throw new Exception("管理员信息不能被删除！");
        }
    }
    //修改
    public boolean editBankCard(T_BALANCE tb)
    {
        return new T_BALANCEDAO().updateBankCard(tb)==1;
        
    }
}

5.工具类

package com.hanqi.utility;

import java.sql.Connection;
import java.sql.SQLException;

import com.mchange.v2.c3p0.ComboPooledDataSource;

//单例模式的数据库工具类
//返回数据库连接
public class DBHepler {
    
    //1.隐藏默认构造方法
    private DBHepler()
    {
        
    }
    //2.静态的实例
    private static DBHepler dh;
    //3.返回实例的静态方法
    public static DBHepler getDBHepler()
    {
        if(dh==null)
        {
            dh = new DBHepler();
        }
        return dh;
    }

    private ComboPooledDataSource cps = new ComboPooledDataSource("helloc3p0");
    //返回连接的方法
    public Connection getConnection() throws SQLException
    {
        return cps.getConnection();
        
    }
}

6.Servlet检查类以及过滤类

package com.hanqi.Controller;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class MyFilter implements Filter {

    
    public MyFilter() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see Filter#destroy()
     */
    public void destroy() {
        // TODO Auto-generated method stub
    }
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        //设置编码
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html");
        response.setCharacterEncoding("UTF-8");
        chain.doFilter(request, response);
    }

    /**
     * @see Filter#init(FilterConfig)
     */
    public void init(FilterConfig fConfig) throws ServletException {
        // TODO Auto-generated method stub
    }

}

package com.hanqi.Controller;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.hanqi.Service.BankCardService;
import com.hanqi.entity.T_BALANCE;


public class CheckLoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    
    public CheckLoginServlet() {
        super();
        
    }

    
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
        //response.getWriter().append("Served at: ").append(request.getContextPath());
        String cardid =request.getParameter("cardid");
        String password =request.getParameter("password");
        //对get，post同时有效
        //username = new String(request.getParameter(username).getBytes("ISO-8859-1"),"UTF-8");
        //检查参数
        if(cardid == null||password==null||
           cardid.trim().equals("")||password.trim().equals(""))
        {
            response.getWriter().println("请正确登录！");
            
            response.setHeader("refresh", "3;url=Login.jsp");
        }
                 
        else
        {
            //验证参数
            //调用Service层
            T_BALANCE tb =new BankCardService().CheckLogin(cardid, password);
            if(tb!=null)
                
            {   //创建session
                HttpSession hs  = request.getSession();
                hs.setAttribute("T_BALANCE", tb);
                
                response.sendRedirect("Main.jsp");
            }
            else
            {
                response.getWriter().println("用户名或密码错误！");
                
                response.setHeader("refresh", "3;url=Login.jsp");
            }
        }
    }

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

}

package com.hanqi.Controller;

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

import com.hanqi.Service.BankCardService;
import com.hanqi.entity.T_BALANCE;


public class SaveBankCardServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    
    public SaveBankCardServlet() {
        super();
       
    }

    
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    
        //完成卡数据的保存
        String userid = request.getParameter("userid");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String state = request.getParameter("state");
        //检查参数
        if(userid == null||password==null|| username ==null ||state==null||
           userid.trim().equals("")||password.trim().equals("")
           ||username.trim().equals("")||state.trim().equals(""))
                {
                    response.getWriter().println("请正确提交！");
                    
                    response.setHeader("refresh", "3;url=Main.jsp");
                }
        //调用模型层
        else
        {
            T_BALANCE tb = new T_BALANCE(userid,username,password,state );
            if (new BankCardService().addBankCard(tb))
            {
                response.getWriter().println("数据添加成功！");
                response.setHeader("refresh", "3;url=Main.jsp");
            }
            else
            {
                response.getWriter().println("数据添加失败！");
                response.setHeader("refresh", "3;url=Main.jsp");
            }
        }
    }

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

}

package com.hanqi.Controller;

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

import com.hanqi.Service.BankCardService;



public class DeleteBankCard extends HttpServlet {
    private static final long serialVersionUID = 1L;
   
    public DeleteBankCard() {
        super();
      
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    
        String cardid = request.getParameter("cardid");
        if(cardid==null||cardid.trim().equals(""))
        {
            response.getWriter().println("请正确提交");
            response.setHeader("refresh", "3;url=Main.jsp");
        }
        else
        {
            try {
                    new BankCardService().removeBankCard(cardid);
                    response.getWriter().println("删除成功");
                
                }
            catch (Exception e) 
            {
                response.getWriter().print(e.getMessage());
            }
            response.setHeader("refresh", "3;Main.jsp");
        }
    }

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

}

package com.hanqi.Controller;

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

import com.hanqi.Service.BankCardService;
import com.hanqi.entity.T_BALANCE;

/**
 * Servlet implementation class UpdateBankCardServlet
 */
public class UpdateBankCardServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public UpdateBankCardServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //完成卡数据的保存
                String cardid = request.getParameter("cardid");
                String userid = request.getParameter("userid");
                String username = request.getParameter("username");
                String password = request.getParameter("password");
                String balance = request.getParameter("balance");
                String state = request.getParameter("state");
                String createtime = request.getParameter("createtime");
                //检查参数
                if(userid == null||password==null|| username ==null ||state==null||
                   userid.trim().equals("")||password.trim().equals("")
                   ||username.trim().equals("")||state.trim().equals(""))
                        {
                            response.getWriter().println("请正确提交！");
                            
                            response.setHeader("refresh", "3;url=Main.jsp");
                        }
                //调用模型层
                else
                {
                    T_BALANCE tb = new T_BALANCE(userid,username,password,state );
                    tb.setCard_ID(cardid);
                    tb.setT_BALANCE(Double.parseDouble(balance));
                    tb.setCreate_time(createtime);
                    if (new BankCardService().editBankCard(tb))
                    {
                        response.getWriter().println("数据保存成功！");
                        response.setHeader("refresh", "3;url=EditBankCard.jsp");
                    }
                    else
                    {
                        response.getWriter().println("数据保存失败！");
                        response.setHeader("refresh", "3;url=EditBankCard.jsp");
                    }
                }
    }

    /**
     * @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);
    }

}

登录界面

<%@ 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>Insert title here</title>
</head>
<body>

<form action="CheckLoginServlet" method="post">
卡号：<input type="text" name="cardid" value=""><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="登录">
</form>
</body>
</html>

主界面

<%@page import="java.text.SimpleDateFormat"%>
<%@page import="java.util.List"%>
<%@page import="com.hanqi.Service.BankCardService"%>
<%@page import="com.hanqi.entity.T_BALANCE"%>

<%@ 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>Insert title here</title>
</head>
<body>
主页面
<br>
<%
Object obj =session.getAttribute("T_BALANCE");
if(obj==null)
{
    out.print("会话超时或未登录");
    response.setHeader("refresh", "3;url=Login.jsp");
}
else
{
    T_BALANCE tb =(T_BALANCE)obj;
    out.print("欢迎登录"+tb.getUser_Name());
}
%>
<br>
添加卡记录
<br>
<form action="SaveBankCardServlet"method="post">
身份证号码：<input type="text" name="userid"><br>
用户名称：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
状态：<input type="text" name="state"><br>
<input type="submit" value="保存">
</form>
<br>
<br>
银行卡数据列表
<br>
<br>
<table cellpadding="0" cellspacing="0" border="1">
<tr>
<td>序号</td>
<td>卡号</td>
<td>用户id</td>
<td>用户名</td>
<td>余额</td>
<td>状态</td>
<td>创建时间</td>
<td>操作</td>
</tr>

<%
//获取所有数据
List<T_BALANCE>ls = new BankCardService().getAllT_BALANCE();
//遍历结果集
int i=0;
//时间格式转换的工具
//SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd HH:mm");
for(T_BALANCE tb :ls)
{
    i++;
    out.print("<tr>");
    out.print("<td>");
    out.print(i);
    out.print("</td>");
    out.print("<td>");
    out.print(tb.getCard_ID());
    out.print("</td>");
    out.print("<td>");
    out.print(tb.getUser_ID());
    out.print("</td>");
    out.print("<td>");
    out.print(tb.getUser_Name());
    out.print("</td>");
    out.print("<td>");
    out.print(tb.getT_BALANCE());
    out.print("</td>");
    out.print("<td>");
    out.print(tb.getState());
    out.print("</td>");
    out.print("<td>");
    out.print(tb.getCreate_time());
    out.print("</td>");
    out.print("<td>");
    out.print("【<a href='EditBankCard.jsp?cardid="+tb.getCard_ID()+"'>修改</a>】 【<a href='DeleteBankCard?cardid="+tb.getCard_ID()+"'>删除</a>】");
    out.print("</td>");
    out.print("</tr>");
}

%>
</table>
</body>
</html>

修改界面

<%@page import="com.hanqi.entity.T_BALANCE"%>
<%@page import="com.hanqi.Service.BankCardService"%>
<%@ 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>Insert title here</title>
</head>
<body>

<%
//接收信息

String cardid = request.getParameter("cardid");
T_BALANCE tb=null;
if(cardid==null||cardid.trim().equals(""))
{
    response.getWriter().print("请正确访问");
    response.setHeader("refresh", "3;url=Main.jsp");
}
else
{
    tb=new BankCardService().getT_BALANCE(cardid);
    if(tb ==null)
    {
        response.getWriter().print("获取数据失败");
        response.setHeader("refresh", "3;url=Main.jsp");

%>
编辑银行卡信息<br><br>
<form action="UpdateBankCardServlet"method="post">
卡号：<input type="text" name="cardid" value="<%=tb.getCard_ID()%>" readonly="readonly"><br>
身份证号：<input type="text" name="userid"value="<%= tb.getUser_ID()%>"><br>
用户名：<input type="text" name="username"value="<%=tb.getUser_Name() %>"><br>
密码：<input type="password" name="password"value="<%=tb.getPassword()%>"><br>
余额：<input type="text" name="balance" value="<%=tb.getT_BALANCE() %>"><br>
状态：<input type="text" name="state"  value="<%=tb.getState()%>"><br>
创建时间：<input type="text" name="createtime" value="<%=tb.getCreate_time()%>"><br>
<br><br>
<input type="submit" value="保存">
</form>
<%    }
} %>
</body>
</html>