网页版增加信息---添加

实验要求：

要求判断任课教师为王建民、刘立嘉、刘丹、封筠、韩培花五位教师的其中一位。

要求上课地点开头为“一教”、“二教”、“三教”、“基教”中的一种

实现数据存储功能。

程序设计思想：

先创建类模型，user

再通过DBUtil和数据库连接

然后在UserDaoImple中实现添加功能

再addInput.jsp文件中实现页面的构建

在add.jsp文件中实现网页添加和判断的功能。

源代码：

 package com.jaovo.msg.model;

public class User {
   private int id;
   private String lesson;
   private String teacher;
   private String status;
public User(int int1, String string, String string2, String string3) {
    // TODO Auto-generated constructor stub
}
public User() {
    // TODO Auto-generated constructor stub
}
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public String getLesson() {
    return lesson;
}
public void setLesson(String lesson) {
    this.lesson = lesson;
}
public String getTeacher() {
    return teacher;
}
public void setTeacher(String teacher) {
    this.teacher = teacher;
}
public String getStatus() {
    return status;
}
public void setStatus(String status) {
    this.status =status;
}
   
}

package com.jaovo.msg.dao;
import com.jaovo.msg.model.User;
import java.util.List;
public interface IUserDao {
    public void add(User user);//添加用户
}

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

import sun.net.www.content.text.plain;

public class UserDaoImpl implements IUserDao {

    @Override
    public void add(User user) {
        //获得链接对象
        Connection connection = DBUtil.getConnection();
        //准备sql语句
        String sql = "select count(*) from t_user where lesson = ?";
        //创建语句传输对象
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        try {
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getLesson());
            //接收结果集
            resultSet = preparedStatement.executeQuery();
            //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(lesson,teacher,status) value (?,?,?)";
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getLesson());
            preparedStatement.setString(2, user.getTeacher());
            preparedStatement.setString(3, user.getStatus());
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            //关闭资源
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        
    }
}

package com.jaovo.msg.filter;
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 CharFilter implements Filter{
   String encoding=null;
@Override
public void destroy() {
    // TODO Auto-generated method stub
    
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    // TODO Auto-generated method stub
    request.setCharacterEncoding("utf-8");    
    request.setCharacterEncoding("encoding");
    chain.doFilter(request, response);
}

@Override
public void init(FilterConfig filterConfig) throws ServletException {
    // TODO Auto-generated method stub
    encoding = filterConfig.getInitParameter("encoding");
}
   
}

package com.jaovo.msg.Util;

import com.jaovo.msg.dao.UserDaoImpl;

public class DaoFactory {
   public static UserDaoImpl getDaoImpl() {
       return new UserDaoImpl();
   }
}

package com.jaovo.msg.Util;

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

public class DBUtil {
    
    public  static  Connection getConnection() {
        try {
            //1 加载驱动
            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";
        Connection connection = null;
        try {
            //2 创建链接对象connection
             connection = DriverManager.getConnection(url,user,password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }
    
    //关闭资源的方法
    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 RuntimeException{

    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
    }
    
}

ValidateUtil
 1 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");
           }
       }
       return validate;
   }
   public static String showError(HttpServletRequest request,String filed)
   {
     Map<String,String> errorMsg=(Map<String,String>)request.getAttribute("errormsg");
     if(errorMsg==null)
     {
         return "";
     }
     String msg=errorMsg.get(filed);
     if(msg==null)
     {
         return "";
     }
     return msg;
   }
}

add.jsp 
1 <%@page import="com.jaovo.msg.Util.UserException"%>
<%@page import="com.jaovo.msg.dao.UserDaoImpl"%>
<%@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 lesson = request.getParameter("lesson");
    String teacher = request.getParameter("teacher");
    String status = request.getParameter("status");
    if(lesson == null || "".equals(lesson.trim())){
        request.setAttribute("error", "用户名不能为空");
    //}
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%
    }
if(lesson!=null&&(lesson.equals("软件工程概论")||lesson.equals("统一建模")||lesson.equals("数据结构")||lesson.equals("离散数学")||lesson.equals("马克思原理")))
{
    
}
else
{
    request.setAttribute("error", "课程信息不在范围里");
    //}
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%        
}
if(teacher!=null&&(teacher.equals("刘丹")||teacher.equals("王建民")||teacher.equals("封筠")||teacher.equals("韩培花")||teacher.equals("刘力嘉")))
{
    
}
else
{
    request.setAttribute("error", "教师姓名不在范围里");
    //}
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%        
}
if(status!=null&&(status.equals("基教")||status.equals("二教")||status.equals("三教")||status.equals("九教")||status.equals("学院楼")))
{
    
}
else
{
    request.setAttribute("error", "任课地点不在范围里");
    //}
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>
<%        
}
    User user = new User();
    user.setLesson(lesson);
    user.setTeacher(teacher);
    user.setStatus(status);
    
    UserDaoImpl userDao = new UserDaoImpl();
    try{
    userDao.add(user);
%>
    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(UserException e){
%>
    <h2 style="color:red ; font-size:50px">发生错误 : <%=e.getMessage() %></h2>
    <%
    }
    %>
</html>

addInput.jsp
 1 <%@ 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>用户添加页面</title>
</head>
<body>
    <%=request.getAttribute("error") %>
    <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="lesson" />
                </td>
            </tr>
                <tr>
                <td>任课教师:</td>
                <td>
                    <input type="text" name="teacher" />
                </td>
            </tr>
            <tr>
                <td>任课地点:</td>
                <td>
                    <input type="text" name="status" />
                </td>
            </tr>
            <tr align="center">
                <td colspan="2">
                    <input type="submit" value="提交" />
                    <input type="reset" value="重置" />
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

运行结果截图：

出现的错误分析：

出错的最基本点还是在特别容易连不上数据库，因为一些小的问题系统就出错误，而且在添加判断的时候，由于对html语言不太熟悉，因为一个花括号加错了一个位置，而出现了整个程序就出了问题，直接网页出现404的错误，当时确实特别懵逼，但是通过李志强及时看出了这个错误，让完成的时间减少了不少。

没完成的地方

就是关于地点的判断还达不到后缀有几零几。

心得：

希望完成这次博客园之后，找一些解决方案，对系统做进一步的分析。