一、PSP0级
二、程序设计思想
编写jsp,dao包内加入方法，连接数据库，测试连接。
三、源代码
<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" />
<%
// if(errorMsg != null){
// if(errorMsg.get("username") != null){
// out.println( errorMsg.get("username"));
// }
// }
%>
</td>
</tr>
<tr>
<td>教师名称:</td>
<td>
<input type="password" name="password" />
<%
// if(errorMsg != null){
// if(errorMsg.get("password") != null){
// out.println( errorMsg.get("password"));
// }
// }
%>
</td>
</tr>
<tr>
<td>上课地点:</td>
<td>
<input type="text" name="nickname" />
<%
// if(errorMsg != null){
// if(errorMsg.get("nickname") != null){
// out.println( errorMsg.get("nickname"));
// }
// }
%>
</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>
<%@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 username = request.getParameter("username");
String password = request.getParameter("passwor");
String nickname = request.getParameter("nickname");
if(username == null || "".equals(username.trim())){
request.setAttribute("error", "用户名不能为空");
%>
<jsp:forward page="addInput.jsp"></jsp:forward>
<%
}
User user = new User();
user.setUsername(username);
user.setPassword(password);
user.setNickname(nickname);
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>
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) {
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("鐢ㄦ埛宸插瓨鍦?") ;
}
}
sql = "insert into t_user(username,password,nickname) value (?,?,?)";
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) {
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 = 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("passwor"));
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("passwor"));
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;
}
}
时间： 2024-07-30 08:29:31