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; } }
原文：http://www.cnblogs.com/youknownothing/p/7911299.html