MyEclipse.6.实战开发讲解视频入门_源代码 6_JSPHelloWorld.zip

/** * */ package user.dao; import java.sql.*; import user.entity.User; /** * 用户数据访问层. * @author BeanSoft * */ public class UserDAO { /** * 根据用户名和密码查找用户, 找到了返回 user 对象. 否则返回 null. * @param user 携带用户名和密码的用户对象 * @return 查找结果 */ public User findUserByUsernamePassword(User user) { // 1. 注册驱动 try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); }// Mysql 的驱动 java.sql.Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; try { // 2. 获取数据库的连接 conn = java.sql.DriverManager.getConnection( "jdbc:mysql://localhost/test?useUnicode=true&characterEncoding=GBK", "root", null); pstmt = conn.prepareStatement("select * from myuser where username = ? and password = ?"); pstmt.setString(1, user.getUsername()); pstmt.setString(2, user.getPassword()); rs = pstmt.executeQuery(); if(rs != null && rs.next()) { user.setId(rs.getInt("id")); return user; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { try { rs.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } try { pstmt.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } try { conn.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } return null; } }