第十六章 JDBC_DAO设计思想与搭建骨架

cn.itcast.jdbc.domain   User  

cn.itcast.jdbc.dao   UserDao   接口

cn.itcast.jdbc.dao.impl   UserDaoJdbcImpl   (implements UserDao 实现方法)

User.java

package cn.itcast.jdbc.domain;

import java.util.Date;

public class User {
	private int id;
	private String name;
	private Date birthday;
	private float money;
	
	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	public float getMoney() {
		return money;
	}

	public void setMoney(float money) {
		this.money = money;
	}
}

 UserDao.java

package cn.itcast.jdbc.dao;

import cn.itcast.jdbc.domain.User;

public interface UserDao {
	public void addUser(User user);

	public User getUser(int userId);

	public User findUser(String loginName, String password);

	public void update(User user);

	public void delete(User user);

}

UserDaoJdbcImpl.java

package cn.itcast.jdbc.dao.impl;

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

import cn.itcast.jdbc.JdbcUtils;
import cn.itcast.jdbc.dao.DaoException;
import cn.itcast.jdbc.dao.UserDao;
import cn.itcast.jdbc.domain.User;

public class UserDaoJdbcImpl implements UserDao {

	public void addUser(User user) {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtils.getConnection();
			String sql = "insert into user(name,birthday, money) values (?,?,?) ";
			ps = conn.prepareStatement(sql);
			ps.setString(1, user.getName());
			ps.setDate(2, new java.sql.Date(user.getBirthday().getTime()));
			ps.setFloat(3, user.getMoney());
			ps.executeUpdate();
		} catch (SQLException e) {
			throw new DaoException(e.getMessage(), e);
		} finally {
			JdbcUtils.free(rs, ps, conn);
		}
	}

	public void delete(User user) {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtils.getConnection();
			st = conn.createStatement();
			String sql = "delete from user where id=" + user.getId();
			st.executeUpdate(sql);
		} catch (SQLException e) {
			throw new DaoException(e.getMessage(), e);
		} finally {
			JdbcUtils.free(rs, st, conn);
		}

	}

	public User findUser(String loginName, String password) {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		User user = null;
		try {
			conn = JdbcUtils.getConnection();
			String sql = "select id, name, money, birthday  from user where name=?";
			ps = conn.prepareStatement(sql);
			ps.setString(1, loginName);
			rs = ps.executeQuery();
			while (rs.next()) {
				user = mappingUser(rs);
			}
		} catch (SQLException e) {
			throw new DaoException(e.getMessage(), e);
		} finally {
			JdbcUtils.free(rs, ps, conn);
		}
		return user;
	}

	public User getUser(int userId) {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		User user = null;
		try {
			conn = JdbcUtils.getConnection();
			String sql = "select id, name, money, birthday  from user where id=?";
			ps = conn.prepareStatement(sql);
			ps.setInt(1, userId);
			rs = ps.executeQuery();
			while (rs.next()) {
				user = mappingUser(rs);
			}
		} catch (SQLException e) {
			throw new DaoException(e.getMessage(), e);
		} finally {
			JdbcUtils.free(rs, ps, conn);
		}
		return user;
	}

	private User mappingUser(ResultSet rs) throws SQLException {
		User user = new User();
		user.setId(rs.getInt("id"));
		user.setName(rs.getString("name"));
		user.setMoney(rs.getFloat("money"));
		user.setBirthday(rs.getDate("birthday"));
		return user;
	}

	public void update(User user) {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtils.getConnection();
			String sql = "update user set name=?, birthday=?, money=? where id=? ";
			ps = conn.prepareStatement(sql);
			ps.setString(1, user.getName());
			ps.setDate(2, new java.sql.Date(user.getBirthday().getTime()));
			ps.setFloat(3, user.getMoney());
			ps.setInt(4, user.getId());
			ps.executeUpdate();
		} catch (SQLException e) {
			throw new DaoException(e.getMessage(), e);
		} finally {
			JdbcUtils.free(rs, ps, conn);
		}
	}

}