软件工程概论课堂测试一（设计添加新课程界面）

设计思想：首先实现界面功能，（包含三个输入框分别是课程名称，老师，上课地点），再添加一个保存按钮。之后建立与数据的连接，将信息保存在数据库中的表中

。之后定义异常处理机制，如果输入与要求不符抛出相应的异常信息，并输出。

源代码：

package com.jaovo.msg.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.ArrayList;


import com.jaovo.msg.Util.DBUtil;
import com.jaovo.msg.model.User;
import com.jaovo.msg.Util.UserException;


public class UserDaoImpl implements IUserDao{

    @Override
    public void add(User user) {
        // TODO Auto-generated method stub
        Connection connection = DBUtil.getConnection();
        
        String sql = "select count(*) from t_user where username = ?";
        
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        try {
            preparedStatement =  connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getUsername());
            
            resultSet = preparedStatement.executeQuery();
            
//            while(resultSet.next()) {
//                if (resultSet.getInt(1) > 0) {
//                    throw new UserException("课程已存在") ;
//                }
//            }
//            
            sql = "insert into t_user(username,password,nickname) value (?,?,?)";
            preparedStatement = (PreparedStatement) connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getUsername());
            preparedStatement.setString(2, user.getPassword());
            preparedStatement.setString(3, user.getNickname());
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        
    }
    

    @Override
    public void delete(int id) {
        // TODO Auto-generated method stub
        
        Connection connection = DBUtil.getConnection();
        String sql = "delete from t_user where id = ?";
        PreparedStatement preparedStatement = null;
        
        try {
            preparedStatement =  connection.prepareStatement(sql);
            preparedStatement.setInt(1, id);
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        
    }

    @Override
    public void update(User user) {
        Connection connection = DBUtil.getConnection();
        
        String sql = "update t_user set password = ? , nickname=? where id = ?";
        
        PreparedStatement preparedStatement = null;
        try {
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getPassword());
            preparedStatement.setString(2, user.getNickname());
            preparedStatement.setInt(3, user.getId());
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
    }

        
    

    @Override
    public User load(int id) {
        Connection connection = DBUtil.getConnection();
        
        String sql = "select * from t_user  where id = ?";
        
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        User user = null;
        try {
            preparedStatement = (PreparedStatement) connection.prepareStatement(sql);
            preparedStatement.setInt(1, id);
            resultSet = preparedStatement.executeQuery();
            while(resultSet.next()) {
                user = new User();
                user.setId(id);
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                user.setNickname(resultSet.getString("nickname"));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        return  user;
    }


    @Override
    public User load(String username) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public List<User> load() {
        Connection connection = DBUtil.getConnection();
        
        String sql = "select * from t_user ";
        
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        
        List<User> users = new ArrayList<User>();
        User user = null;
        try {
            preparedStatement = connection.prepareStatement(sql);
            resultSet = preparedStatement.executeQuery();
            while(resultSet.next()) {
                user = new User();
                user.setId(resultSet.getInt("id"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                user.setNickname(resultSet.getString("nickname"));
                users.add(user);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        return  users;
    }

}

package com.jaovo.msg.model;

public class User {
    private int id;
    private String  username;
    private String  nickname;
    private String  password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getNickname() {
        return nickname;
    }
    public void setNickname(String nickname) {
        this.nickname = nickname;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    

}

package com.jaovo.msg.Util;

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

import java.sql.PreparedStatement;

public class DBUtil {
    public  static  Connection getConnection() {

        try {
            
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String user = "root";
        String password = "root";
        String url = "jdbc:mysql://localhost:3306/mysql?useUnicode=true&characterEncoding=UTF-8";
        Connection connection = null;
        try {
            
             connection = DriverManager.getConnection(url,user,password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }
    
    
    public static void close(Connection connection ) {
        try {
            if (connection != null) {
                connection.close();
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void close(PreparedStatement preparedStatement ) {
        try {
            if (preparedStatement != null) {
                preparedStatement.close();
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void close(ResultSet resultSet ) {
        try {
            if (resultSet != null) {
                resultSet.close();
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    



}

package com.jaovo.msg.Util;

public class UserException  extends Exception{

    public UserException() {
        super();
        // TODO Auto-generated constructor stub
    }

    public UserException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
        // TODO Auto-generated constructor stub
    }

    public UserException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

    public UserException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public UserException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }

    

    
    
}

package com.jaovo.msg.Util;

public class UserException1   extends Exception{

    public UserException1() {
        super();
        // TODO Auto-generated constructor stub
    }
    

    
    public UserException1(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    
    
} 

-- mysal -u root -p root;
-- show databases;
-- drop database jaovo_shop;

create database jaovo_msg;
use jaovo_msg;
GRANT ALL ON jaovo_msg.* to "jaovo"@"localhost" IDENTIFIED BY "root";
create table t_user(
     id int(10) primary key auto_increment,
     username varchar(255),
     password varchar(255),
     nickname varchar(255),
     type int(2),
     status int(2)
);

create table t_message(
   id          int(10) primary key auto_increment,                
   title                varchar(254),
   content              text,
   post_date             datetime,
   user_id               int(10),
   CONSTRAINT FOREIGN KEY(user_id) REFERENCES t_user(id)
);

create table t_comment(
   id        int(10) primary key auto_increment,  
   content       text,
   post_date     datetime,
   user_id       int(10),
   msg_id        int(10),
   CONSTRAINT FOREIGN KEY(user_id) REFERENCES t_user(id),
   CONSTRAINT FOREIGN KEY(msg_id) REFERENCES t_message(id)
);

<%@page import="com.jaovo.msg.Util.UserException"%>
<%@page import="com.jaovo.msg.dao.UserDaoImpl"%>
<%@page import="com.jaovo.msg.Util.UserException"%>
<%@page import="com.jaovo.msg.model.User"%>
<%@ 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>

<%
    //接收客户端传递过来的参数
    
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    String nickname = request.getParameter("nickname");
    

    
    try{
    if(!password.equals("王建民")&&!password.equals("刘丹")&&!password.equals("刘立嘉"))
    {
        throw new UserException( "教师名不存在");
    
    }
    if(!nickname.startsWith("基教")&&!nickname.startsWith("一教")&&!nickname.startsWith("二教")&&!nickname.startsWith("三教"))
    {
        throw new UserException( "教室不存在");
    }
    User user = new User();
    user.setUsername(username);
    user.setPassword(password);
    user.setNickname(nickname);
    
    UserDaoImpl userDao = new UserDaoImpl();
    
        userDao.add(user);
%>


    课程保存成功!!<br>
    <a href="addInput.jsp">继续添加</a><br>
    
<%
    }catch(UserException e){
%>
    <h2 style="color:red ; font-size:50px">发生错误 : <%=e.getMessage() %></h2>
    <%
    }
    %>
</html>

<%@ 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>
    <title>课程添加页面</title>
</head>
<body>

    <form action="add.jsp" method="get">
        <table align="center" border="1" width="500">
            <tr>
                <td>课程名称 : </td>
                <td>
                    <input type="text" name="username" />
                    
                </td>
            </tr>
                <tr>
                <td>任课教师:</td>
                <td>
                    <input type="text" name="password" />
                </td>
            </tr>
            <tr>
                <td>上课地点:</td>
                <td>
                    <input type="text" name="nickname" />
                </td>
            </tr>
            <tr align="center">
                <td colspan="2">
                    <input type="submit" value="保存" />
                    
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

package com.jaovo.msg.dao;



import java.util.List;

import com.jaovo.msg.model.User;

public interface IUserDao {
    public void add(User user);
    public void delete(int id);
    public void update(User user);
    public User load(int id);
    public User load(String username);
    public List<User> load();

}

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>User_Message1</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

运行截图：

计划总结：