基于jsp+servlet+javabean的MVC模式简单应用

Posted 2020-10-04

原先写在CSDN的一篇，我直接扒过来吧。之前打算在CSDN的，结果写了几回，发现他那个发布系统简直烂到家，经常丢失图片各种。所以很长一段时间我也没写什么。

一、MVC模式

    1、M :  javabean;

    2、V :  jsp;

    3、C : servlet;

    4、DB：MySQL；

二、文件夹

 

三、项目内容

1、建立数据库并封装数据库操作  

create database testDB;  
  
use testDB;  
  
create table user  
(  
id int auto_increment primary key,  
username varchar(20),  
password varchar(20),  
phone varchar(20),  
addr varchar(225)  
);  

 

/** 
 * 封装数据库操作 
 * 包括对javabean存储的操作； 
 */  
  
import java.sql.*;  
  
import com.yck.mvc.bean.User;  
  
public class DB  
 {  
    static  
    {  
        try  
        {  
            Class.forName("com.mysql.jdbc.Driver");   
        } catch (ClassNotFoundException e)  
        {  
            e.printStackTrace();  
        }         
    }  
      
    public static Connection getConnection()  
    {  
        Connection connection = null;  
        try  
        {  
            connection = DriverManager.getConnection("jdbc:mysql://localhost/testdb?user=root&password=yck940522");  
              
        } catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
        return connection;  
    }  
      
    public static void closeConnection(Connection connection)  
    {  
        try  
        {  
            if(connection != null)  
            {  
                connection.close();  
                connection = null;  
            }  
        }  catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
    }  
      
    public static PreparedStatement preparedStatement(Connection connection,String sql)  
    {  
        PreparedStatement preparedStatement = null;  
        try  
        {     
            preparedStatement = connection.prepareStatement(sql);  
        } catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
        return preparedStatement;  
    }  
    public static void closePreparedStatement(PreparedStatement preparedStatement)  
    {  
        try  
        {  
            if(preparedStatement != null)  
            {  
                preparedStatement.close();  
                preparedStatement = null;  
            }  
        }  catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
    }  
      
    public static Statement createStatement(Connection connection)  
    {  
        Statement statement = null;  
        try  
        {     
            statement = connection.createStatement();  
        } catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
        return statement;  
    }  
    public static void closeStatement(Statement statement)  
    {  
        try  
        {  
            if(statement != null)  
            {  
                statement.close();  
                statement = null;  
            }  
        }  catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
    }  
    public static ResultSet getResultSet(Statement statement,String sql)  
    {  
        ResultSet resultSet = null;  
        try  
        {     
            resultSet = statement.executeQuery(sql);  
        } catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
        return resultSet;  
    }  
    public static void closeResultSet(ResultSet resultSet)  
    {  
        try  
        {  
            if(resultSet != null)  
            {  
                resultSet.close();  
                resultSet = null;  
            }  
        }  catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
    }  
      
    //构造在数据库中存储User的方法  
      
    public static void saveUser(User u)  
    {  
        Connection connection = null;  
        PreparedStatement preparedStatement = null;  
        try  
        {  
            connection = DB.getConnection();  
            String sql = "insert into user values(null,?,?,?,?)";  
            preparedStatement = DB.preparedStatement(connection, sql);  
            preparedStatement.setString(1, u.getUsername());  
            preparedStatement.setString(2, u.getPassword());  
            preparedStatement.setString(3, u.getPhone());  
            preparedStatement.setString(4, u.getAddr());  
            preparedStatement.executeUpdate();    
        }  catch (SQLException e)  
        {  
            e.printStackTrace();  
        }  
    }     
 }  

2、建立Model：封装User

public class User  
{  
    private String username;  
    private String password;  
    private String phone;  
    private String addr;  
    public String getUsername()  
    {  
        return username;  
    }  
    public void setUsername(String username)  
    {  
        this.username = username;  
    }  
    public String getPassword()  
    {  
        return password;  
    }  
    public void setPassword(String password)  
    {  
        this.password = password;  
    }  
    public String getPhone()  
    {  
        return phone;  
    }  
    public void setPhone(String phone)  
    {  
        this.phone = phone;  
    }  
    public String getAddr()  
    {  
        return addr;  
    }  
    public void setAddr(String addr)  
    {  
        this.addr = addr;  
    }  
      
  
}  

3 建立View：写jsp页面

    1）register.jsp

<%@ 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>注册用户</title>  
</head>  
<body>  
<form name="regiserForm" action="http://localhost:8080/MVC/RegisterServlet" method = "post">  
    <table id="registerTableId" align="center">  
        <tr>  
            <td colspan="2" align="center">用户注册</td>  
        </tr>  
        <tr>  
            <td>用户名</td> <td><input id="usernameId" type="text" name="username"></td>  
            <td><span id="usernameTipId"></span></td>  
        </tr>  
         <tr>  
            <td>密码</td> <td><input id="passwordId" type="password" name="password"></td>  
            <td><span id="passwordTipId"></span></td>  
        </tr>  
         <tr>  
            <td>密码确认</td> <td><input id="password2Id" type="password" name="password2"></td>  
            <td><span id="password2TipId"></span></td>  
        </tr>  
         <tr>  
            <td>手机号码</td> <td><input id="phoneId" type="text" name="phone"></td>  
            <td><span id="phoneTipId"></span></td>  
        </tr>  
         <tr>  
            <td>地址</td> <td><textarea id="addrId" name="addr" rows="3" cols="25"></textarea></td>  
        </tr>  
         <tr>  
            <td><input id="registerSubmitId" type="submit" value="提交"></td>  
            <td><input id="registerResetId" type="reset" value="重置"></td>  
        </tr>  
          
    </table>  
</form>  
  
</body>  
</html>  

2）registerInfo.jsp 显示注册信息

<%@ 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>注册成功</title>  
</head>  
<body>  
<jsp:useBean id="registerUser" class="com.yck.mvc.bean.User" scope="session"></jsp:useBean>  
<table id="registerInfoId" align="center">  
    <tr><td colspan="2" align="center">用户信息</td></tr>  
    <tr>  
        <td>用户名</td> <td> <jsp:getProperty property="username" name="registerUser"/></td>   
    </tr>  
    <tr>  
        <td>手机号码</td> <td> <jsp:getProperty property="phone" name="registerUser"/></td>   
    </tr>  
    <tr>  
        <td>地址</td> <td> <jsp:getProperty property="addr" name="registerUser"/></td>   
    </tr>  
</table>  
  
</body>  
</html>  

4、建立Control层：写servlet

 

RegisterServlet

import java.io.IOException;  
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 com.yck.mvc.DButil.DB;  
import com.yck.mvc.bean.User;  
  
/** 
 * Servlet implementation class RegisterServlet 
 */  
@WebServlet("/RegisterServlet")  
public class RegisterServlet extends HttpServlet {  
    private static final long serialVersionUID = 1L;  
         
    /** 
     * @see HttpServlet#HttpServlet() 
     */  
    public RegisterServlet() {  
        super();  
        // TODO Auto-generated constructor stub  
    }  
  
    /** 
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 
     */  
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException   
    {  
        doPost(request,response);  
      
    }  
  
    /** 
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
     */  
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException   
    {  
        request.setCharacterEncoding("utf-8");  
        try  
        {  
            String username = request.getParameter("username");  
            String password = request.getParameter("password");  
            String phone = request.getParameter("phone");  
            String addr = request.getParameter("addr");  
            User u = new User();  
            u.setUsername(username);  
            u.setPassword(password);  
            u.setPhone(phone);  
            u.setAddr(addr);  
            DB.saveUser(u);  
              
            request.getSession().setAttribute("registerUser", u);  
            request.getRequestDispatcher("registerInfo.jsp").forward(request, response);  
        } catch (Exception e)  
        {  
            e.printStackTrace();  
        }  
              
    }  
  
}  

　　那边也没有测试的结果图，我猜肯定是挂了。CSDN毛病特别多，作者甚至不能预览自己写的东西。提交之后在审核的过程中，点击自己的文章就是报错，所以我都是写完就丢那