超级课程表

1程序设计思想

首先在addInput.jsp 界面中完成网页界面的设计，进行网页测试，看是否完成设计，然后在数据库中建立表，在daoimpi 类文件中进行数据的链接，进行测试，在add.jsp文件中进行判断输入的字符是否合法，建立一个自定义异常类ClassException，在try 中进行输入字符的判断，然后进行抛出异常，最后catch异常，用标签将错误原因显示在网页上

2源程序代码

IUserDao.java

package com.jaovo.msg.dao;

import com.jaovo.msg.mobeI.User;

public interface IUserDao {
    public void add(User user);//添加

}

UserdaoImpI.java  数据库的链接

package com.jaovo.msg.dao;//实现方法的类

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Connection;
import com.jaovo.msg.Util.DBUtil;
import com.jaovo.msg.Util.UserException;
import com.jaovo.msg.mobeI.User;

public class UserdaoImpI implements IUserDao
{//实现接口中的所有方法   6步

    @SuppressWarnings("resource")
    @Override
    public void add(User user)
    {//增加的方法
        // TODO Auto-generated method stub
        Connection connection=DBUtil.getConnection();//获得连接对象
        //准备sql语句
        String sql = "select count(*) from t_user where username = ?";//count 数据的条数
        //创建语句传输对象
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;//
        try {
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getKecheng());
            resultSet = preparedStatement.executeQuery();//接受一下结果集
            //遍历结果集
            while(resultSet.next()) {
                if(resultSet.getInt(1) > 0) {
                    throw new UserException("用户已存在") ;
                    };
                }
        sql = "insert into t_user(username,password,nickname) values (?,?,?)";
        preparedStatement = connection.prepareStatement(sql);
        preparedStatement.setString(1, user.getKecheng());
        preparedStatement.setString(2, user.getTeacher());
        preparedStatement.setString(3, user.getAdress());
        preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
    }
}

User。Java

package com.jaovo.msg.mobeI;

public class User {
    private int id;
    private String kecheng;
    private String teacher;
    private String adress;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getKecheng() {
        return kecheng;
    }
    public void setKecheng(String kecheng) {
        this.kecheng = kecheng;
    }
    public String getAdress() {
        return adress;
    }
    public void setAdress(String adress) {
        this.adress = adress;
    }
    public String getTeacher() {
        return teacher;
    }
    public void setTeacher(String teacher) {
        this.teacher = teacher;
    }

}

ClassException.java

package com.jaovo.msg.Util;

public class ClassException extends Exception{
    /**
     *
     */
    private static final long serialVersionUID = 1L;

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

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

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

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

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

}

DBUtil.java

package com.jaovo.msg.Util;//链接数据库的方法
/*
 1加载驱动
 2创建连接对象
 3创建语句传输对象
 4接受结果集对象
 5遍历
 6关闭资源
 */
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.apache.tomcat.dbcp.dbcp2.DriverManagerConnectionFactory;

public class DBUtil {
    public static Connection getConnection() {
        //1.加载驱动
        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/jaovo_msg?useUnicode=true&characterEncoding=UTF-8";//连接数据库的代码
        Connection connection = null;//提升定域
        try {
            //2创建连接对象
            connection = DriverManager.getConnection(url,user,password);//连接数据库的对象
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }
    //关闭资源方法
    public static void close(Connection connection) {//连接对象的关闭
        try {
            if(connection != null) {//空指针异常
                connection.close();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void close(PreparedStatement preparedStatement) {//语句传输对象关闭
        try {
            if(preparedStatement != null) {
                preparedStatement.close();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void close(ResultSet resultSet) {//关闭结果集对象  主要针对查询的对象
        try {
            if(resultSet != null) {
                resultSet.close();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

ValidateUtil.java

package com.jaovo.msg.Util;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
public class ValidateUtil
{
    public static boolean validateNull(HttpServletRequest request,String[] fileds)
    {
        boolean validate=true;
        //Map对象用来装载不同的错误信息
        Map<String,String>errorMsg=new HashMap();
        for(String filed:fileds)
        {
            String value=request.getParameter(filed);
            if(value==null||"".equals(value.trim()))
            {
                validate=false;
                errorMsg.put(filed, filed+"不能为空");
            }
            if(!validate)
            {
                request.setAttribute("errormsg",errorMsg);
            }
        }
        return validate;
    }
}

add.jsp

<%@page import="com.jaovo.msg.Util.ClassException"%>
<%@page import="com.jaovo.msg.Util.UserException"%>
<%@page import="com.jaovo.msg.dao.UserdaoImpI"%>
<%@page import="com.jaovo.msg.mobeI.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>

<% //接受客户端传递过来的参数
    request.setCharacterEncoding("UTF-8");
    String kecheng = request.getParameter("kecheng");
    String teacher = request.getParameter("teacher");
    String adress = request.getParameter("adress");
    try{
        if(!teacher.trim().equals("王建民")&&!teacher.trim().equals("刘立嘉")&&!teacher.trim().equals("刘丹")&&!teacher.trim().equals("杨子光")&&!teacher.trim().equals("王辉"))
        {
            throw new ClassException("不能输入");
        }
        else if (!adress.trim().startsWith("基教")&&!adress.trim().startsWith("一教")&&!adress.trim().startsWith("二教")&&!adress.trim().startsWith("三教"))
        {
            throw new ClassException("不能输入");
        }
        else
        {
            User user = new User();
            user.setKecheng(kecheng);
            user.setTeacher(teacher);
            user.setAdress(adress);
            UserdaoImpI userDao = new UserdaoImpI();
            userDao.add(user);
            %>

<body>
    用户保存成功!!<br>
    <a href="addInput.jsp">继续添加</a><br>
    <a href="#">用户列表</a>
            <%
        }
    }
    catch(ClassException e){
        %>
            <h2 style="color:red ; font-size:50px">发生错误 : <%=e.getMessage() %></h2>
        <%
            }

    %>

</html>

addInput.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>
    <title>课程添加界面</title>
</head>
<body>
    <form action = "add.jsp" method = "post">
        <table align = "center" border="1" width="500" >
            <tr>
                <td>课程名称：</td>
                <td>
                    <input type ="text" name = "kecheng"/>
                </td>
            </tr>
                <tr>
                    <td>任课教师：</td>
                <td>
                    <input type = "text" name = "teacher"/>
                </td>
                <tr>
                    <td>上课地点：</td>
                    <td>
                        <input type = "text" name = "adress"     />
                    </td>
                </tr>
                <tr align="center">
                    <td colspan = "2">
                        <input type = "submit" value = "保存"/>

                        </td>
        </table>

    </form>
</body>
</html>

程序执行结果截图

psp日志

总结：在进行有关项目的编码是，需要注意编程上的规范，在写完每一个部分之后都需要进行测试，防止程序出现不可逆转的错误，加大程序完成的效率，将时间更多的用来学习只是和巩固住已经学习的知识。