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;
 2 
 3 public class User {
 4    private int id;
 5    private String lesson;
 6    private String teacher;
 7    private String status;
 8 public User(int int1, String string, String string2, String string3) {
 9     // TODO Auto-generated constructor stub
10 }
11 public User() {
12     // TODO Auto-generated constructor stub
13 }
14 public int getId() {
15     return id;
16 }
17 public void setId(int id) {
18     this.id = id;
19 }
20 public String getLesson() {
21     return lesson;
22 }
23 public void setLesson(String lesson) {
24     this.lesson = lesson;
25 }
26 public String getTeacher() {
27     return teacher;
28 }
29 public void setTeacher(String teacher) {
30     this.teacher = teacher;
31 }
32 public String getStatus() {
33     return status;
34 }
35 public void setStatus(String status) {
36     this.status =status;
37 }
38    
39 }

1 package com.jaovo.msg.dao;
2 import com.jaovo.msg.model.User;
3 import java.util.List;
4 public interface IUserDao {
5     public void add(User user);//添加用户
6 }

 1 package com.jaovo.msg.dao;
 2 
 3 import java.sql.Connection;
 4 import java.sql.PreparedStatement;
 5 import java.sql.ResultSet;
 6 import java.sql.SQLException;
 7 import java.util.ArrayList;
 8 import java.util.List;
 9 
10 
11 import com.jaovo.msg.Util.DBUtil;
12 import com.jaovo.msg.Util.UserException;
13 import com.jaovo.msg.model.User;
14 
15 import sun.net.www.content.text.plain;
16 
17 public class UserDaoImpl implements IUserDao {
18 
19     @Override
20     public void add(User user) {
21         //获得链接对象
22         Connection connection = DBUtil.getConnection();
23         //准备sql语句
24         String sql = "select count(*) from t_user where lesson = ?";
25         //创建语句传输对象
26         PreparedStatement preparedStatement = null;
27         ResultSet resultSet = null;
28         try {
29             preparedStatement = connection.prepareStatement(sql);
30             preparedStatement.setString(1, user.getLesson());
31             //接收结果集
32             resultSet = preparedStatement.executeQuery();
33             //遍历结果集
34             while(resultSet.next()) {
35                 if (resultSet.getInt(1) > 0) {
36                     throw new UserException("用户已存在") ;
37                 }
38             }
39             
40             sql = "insert into t_user(lesson,teacher,status) value (?,?,?)";
41             preparedStatement = connection.prepareStatement(sql);
42             preparedStatement.setString(1, user.getLesson());
43             preparedStatement.setString(2, user.getTeacher());
44             preparedStatement.setString(3, user.getStatus());
45             preparedStatement.executeUpdate();
46         } catch (SQLException e) {
47             // TODO Auto-generated catch block
48             e.printStackTrace();
49         }finally {
50             //关闭资源
51             DBUtil.close(resultSet);
52             DBUtil.close(preparedStatement);
53             DBUtil.close(connection);
54         }
55         
56     }
57 }

 1 package com.jaovo.msg.filter;
 2 import java.io.IOException;
 3 
 4 import javax.servlet.Filter;
 5 import javax.servlet.FilterChain;
 6 import javax.servlet.FilterConfig;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.ServletRequest;
 9 import javax.servlet.ServletResponse;
10 public class CharFilter implements Filter{
11    String encoding=null;
12 @Override
13 public void destroy() {
14     // TODO Auto-generated method stub
15     
16 }
17 
18 @Override
19 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
20     // TODO Auto-generated method stub
21     request.setCharacterEncoding("utf-8");    
22     request.setCharacterEncoding("encoding");
23     chain.doFilter(request, response);
24 }
25 
26 @Override
27 public void init(FilterConfig filterConfig) throws ServletException {
28     // TODO Auto-generated method stub
29     encoding = filterConfig.getInitParameter("encoding");
30 }
31    
32 }

1 package com.jaovo.msg.Util;
2 
3 import com.jaovo.msg.dao.UserDaoImpl;
4 
5 public class DaoFactory {
6    public static UserDaoImpl getDaoImpl() {
7        return new UserDaoImpl();
8    }
9 }

 1 package com.jaovo.msg.Util;
 2 
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 import java.sql.PreparedStatement;
 6 import java.sql.ResultSet;
 7 import java.sql.SQLException;
 8 
 9 public class DBUtil {
10     
11     public  static  Connection getConnection() {
12         try {
13             //1 加载驱动
14             Class.forName("com.mysql.jdbc.Driver").newInstance();
15         } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
16             // TODO Auto-generated catch block
17             e.printStackTrace();
18         }
19         String user = "root";
20         String password = "root";
21         String url = "jdbc:mysql://localhost:3306/jaovo_msg";
22         Connection connection = null;
23         try {
24             //2 创建链接对象connection
25              connection = DriverManager.getConnection(url,user,password);
26         } catch (SQLException e) {
27             // TODO Auto-generated catch block
28             e.printStackTrace();
29         }
30         return connection;
31     }
32     
33     //关闭资源的方法
34     public static void close(Connection connection ) {
35         try {
36             if (connection != null) {
37                 connection.close();
38             }
39             
40         } catch (SQLException e) {
41             // TODO Auto-generated catch block
42             e.printStackTrace();
43         }
44     }
45     public static void close(PreparedStatement preparedStatement ) {
46         try {
47             if (preparedStatement != null) {
48                 preparedStatement.close();
49             }
50             
51         } catch (SQLException e) {
52             // TODO Auto-generated catch block
53             e.printStackTrace();
54         }                                                 
55     }
56     public static void close(ResultSet resultSet ) {
57         try {
58             if (resultSet != null) {
59                 resultSet.close();
60             }
61             
62         } catch (SQLException e) {
63             // TODO Auto-generated catch block
64             e.printStackTrace();
65         }
66     }
67     
68 }

 1 package com.jaovo.msg.Util;
 2 
 3 public class UserException extends RuntimeException{
 4 
 5     public UserException() {
 6         super();
 7         // TODO Auto-generated constructor stub
 8     }
 9     public UserException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
10         super(message, cause, enableSuppression, writableStackTrace);
11         // TODO Auto-generated constructor stub
12     }
13     public UserException(String message, Throwable cause) {
14         super(message, cause);
15         // TODO Auto-generated constructor stub
16     }
17 
18     public UserException(String message) {
19         super(message);
20         // TODO Auto-generated constructor stub
21     }
22 
23     public UserException(Throwable cause) {
24         super(cause);
25         // TODO Auto-generated constructor stub
26     }
27     
28 }

ValidateUtil
 1 package com.jaovo.msg.Util;
 2 import java.util.HashMap;
 3 import java.util.Map;
 4 import javax.servlet.http.HttpServletRequest;
 5 public class ValidateUtil {
 6    public static boolean validateNull(HttpServletRequest request,String[] fileds)
 7    {
 8        boolean validate=true;
 9        //map对象用来装载不同的错误信息
10        Map<String,String> errorMsg=new HashMap();
11        for(String filed:fileds)
12        {
13            String value=request.getParameter(filed);
14            if(value==null||"".equals(value.trim()))
15            {
16                validate=false;
17                errorMsg.put(filed,filed+"不能为空");
18            }
19        }
20        return validate;
21    }
22    public static String showError(HttpServletRequest request,String filed)
23    {
24      Map<String,String> errorMsg=(Map<String,String>)request.getAttribute("errormsg");
25      if(errorMsg==null)
26      {
27          return "";
28      }
29      String msg=errorMsg.get(filed);
30      if(msg==null)
31      {
32          return "";
33      }
34      return msg;
35    }
36 }

add.jsp 
1 <%@page import="com.jaovo.msg.Util.UserException"%>
 2 <%@page import="com.jaovo.msg.dao.UserDaoImpl"%>
 3 <%@page import="com.jaovo.msg.model.User"%>
 4 <%@ page language="java" contentType="text/html; charset=UTF-8"
 5     pageEncoding="UTF-8"%>
 6 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 7 <html>
 8 <%
 9     //接收客户端传递过来的参数
10     String lesson = request.getParameter("lesson");
11     String teacher = request.getParameter("teacher");
12     String status = request.getParameter("status");
13     if(lesson == null || "".equals(lesson.trim())){
14         request.setAttribute("error", "用户名不能为空");
15     //}
16 %>
17     <jsp:forward page="addInput.jsp"></jsp:forward>
18 <%
19     }
20 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")))
21 {
22     
23 }
24 else
25 {
26     request.setAttribute("error", "课程信息不在范围里");
27     //}
28 %>
29     <jsp:forward page="addInput.jsp"></jsp:forward>
30 <%        
31 }
32 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")))
33 {
34     
35 }
36 else
37 {
38     request.setAttribute("error", "教师姓名不在范围里");
39     //}
40 %>
41     <jsp:forward page="addInput.jsp"></jsp:forward>
42 <%        
43 }
44 if(status!=null&&(status.equals("基教")||status.equals("二教")||status.equals("三教")||status.equals("九教")||status.equals("学院楼")))
45 {
46     
47 }
48 else
49 {
50     request.setAttribute("error", "任课地点不在范围里");
51     //}
52 %>
53     <jsp:forward page="addInput.jsp"></jsp:forward>
54 <%        
55 }
56     User user = new User();
57     user.setLesson(lesson);
58     user.setTeacher(teacher);
59     user.setStatus(status);
60     
61     UserDaoImpl userDao = new UserDaoImpl();
62     try{
63     userDao.add(user);
64 %>
65     用户保存成功!!<br>
66     <a href="addInput.jsp">继续添加</a><br>
67     <a href="#">用户列表</a>
68 <%
69     }catch(UserException e){
70 %>
71     <h2 style="color:red ; font-size:50px">发生错误 : <%=e.getMessage() %></h2>
72     <%
73     }
74     %>
75 </html>

addInput.jsp
 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6     <title>用户添加页面</title>
 7 </head>
 8 <body>
 9     <%=request.getAttribute("error") %>
10     <form action="add.jsp" method="get">
11         <table align="center" border="1" width="500">
12             <tr>
13                 <td>课程名称 : </td>
14                 <td>
15                     <input type="text" name="lesson" />
16                 </td>
17             </tr>
18                 <tr>
19                 <td>任课教师:</td>
20                 <td>
21                     <input type="text" name="teacher" />
22                 </td>
23             </tr>
24             <tr>
25                 <td>任课地点:</td>
26                 <td>
27                     <input type="text" name="status" />
28                 </td>
29             </tr>
30             <tr align="center">
31                 <td colspan="2">
32                     <input type="submit" value="提交" />
33                     <input type="reset" value="重置" />
34                 </td>
35             </tr>
36         </table>
37     </form>
38 </body>
39 </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。

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原文地址：https://www.cnblogs.com/lovema1210/p/7911200.html