Mybatis-05-原始dao开发方法

本节来介绍原始dao的开发方法，原始dao方式存在一些问题，比如：存在大量的模板代码（session.close()、session.commit()。。。）、在调用SqlSession的方法时参数statement的ID存在硬编码，且传入的参数变量值由于泛型的原因有可能会出现类型传递错误（但是编译器并不报错，只在运行时会出错）。

原始dao方法虽然不建议使用，但是在实际开发项目中有时候也会用到，在此简单录一下。

1、数据库表结构：

 一个单表（user），很简单，不多说。

2、模型类：

package com.wp.model;

import java.util.Date;

public class User {
	
	private int id;
	private String userName;
	private int sex;
	private int age;
	private Date birthDay;
	private String address;
	
	// get   set
	
	public User() {
		super();
	}
	
	public User(int id, String userName, int sex, int age, Date birthDay,
			String address) {
		super();
		this.id = id;
		this.userName = userName;
		this.sex = sex;
		this.age = age;
		this.birthDay = birthDay;
		this.address = address;
	}
	
	public User(String userName, int sex, int age, Date birthDay, String address) {
		super();
		this.userName = userName;
		this.sex = sex;
		this.age = age;
		this.birthDay = birthDay;
		this.address = address;
	}
	
	public String toString() {
		return "User [address=" + address + ", age=" + age + ", birthDay="
				+ birthDay + ", id=" + id + ", sex=" + sex + ", userName="
				+ userName + "]";
	}
	
}

3、mybatis全局配置文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration 
	PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 
	"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
	<!-- 加载数据库配置文件 -->
	<properties resource="db.properties"/>

	<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC"/>
			<!-- 配置数据源信息 -->
			<dataSource type="POOLED">
				<property name="driver" value="${jdbc.driver}"/>
				<property name="url" value="${jdbc.url}"/>
				<property name="username" value="${jdbc.username}"/>
				<property name="password" value="${jdbc.password}"/>
			</dataSource>
		</environment>
	</environments>
	
	<!-- 加载映射文件 -->
	<mappers>
		<mapper resource="mapper/User.xml"/>
	</mappers>
</configuration>

4、映射文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
	PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
	"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="UserSpace">
	
	<!-- 根据用户ID查询用户 -->
	<select id="selectById" parameterType="java.lang.Integer" resultType="com.wp.model.User">
		select * from user where id=#{id}
	</select>
	
	<!-- 根据用户名称模糊查询用户 -->
	<select id="selectByVagueName" parameterType="java.lang.String" resultType="com.wp.model.User">
		select * from user where username like #{username}
	</select>
	
	<!-- 添加用户 -->
	<insert id="addUser" parameterType="com.wp.model.User">
		insert into user(username, sex, age, birthday, address)
		values(#{userName}, #{sex}, #{age}, #{birthDay}, #{address})
	</insert>
	
	<!-- 更新用户 -->
	<update id="updateUser" parameterType="com.wp.model.User">
		update user set username=#{userName}, sex=#{sex}, age=#{age}, 
		birthday=#{birthDay}, address=#{address}
		where id=#{id}
	</update>
	
	<!-- 删除用户 -->
	<delete id="deleteById" parameterType="java.lang.Integer">
		delete from user where id=#{id}
	</delete>
	
</mapper>

5、dao接口：

package com.wp.dao;

import java.util.List;

import com.wp.model.User;

public interface UserDao {
	
	public User getById(int id);
	
	public List<User> getByName(String userName);
	
	public void add(User user);
	
	public void update(User user);
	
	public void delete(int id);
	
}

6、接口实现类：

     由于SqlSessionFactory是线程安全的，因此在实现类中共用一个SqlSessionFactory即可。但是SqlSession绝对不能共用。

package com.wp.dao.impl;

import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import com.wp.dao.UserDao;
import com.wp.model.User;

public class UserDaoImpl implements UserDao {

	private SqlSessionFactory sessionFactory; 
	
	public UserDaoImpl(SqlSessionFactory sessionFactory) {
		this.sessionFactory = sessionFactory;
	}

	@Override
	public void add(User user) {
		SqlSession session = this.sessionFactory.openSession();
		session.insert("UserSpace.addUser", user);
		session.commit();
		session.close();
	}

	@Override
	public void delete(int id) {
		SqlSession session = this.sessionFactory.openSession();
		session.delete("UserSpace.deleteById", id);
		session.commit();
		session.close();
	}

	@Override
	public User getById(int id) {
		SqlSession session = this.sessionFactory.openSession();
		User user = session.selectOne("UserSpace.selectById", id);
		session.close();
		return user;
	}

	@Override
	public List<User> getByName(String userName) {
		SqlSession session = this.sessionFactory.openSession();
		List<User> userList = session.selectList("UserSpace.selectByVagueName", userName);
		session.close();
		return userList;
	}

	@Override
	public void update(User user) {
		SqlSession session = this.sessionFactory.openSession();
		session.update("UserSpace.updateUser", user);
		session.commit();
		session.close();
	}

}

7、测试程序：

    在测试类开始获取全局的SqlSessionFactory，并传递给接口实现类。

package com.wp.dao.impl;

import java.io.InputStream;
import java.util.Date;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import com.wp.dao.UserDao;
import com.wp.model.User;
import com.wp.util.DateUtil;

public class UserDaoImplTest {

	private SqlSessionFactory sessionFactory;
	
	@Before
	public void setUp() throws Exception {
		String resource = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		this.sessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
	}

	@Test
	public void testAdd() {
		Date date = DateUtil.parseStrToFullDate("2001-11-20", "yyyy-MM-dd");
		User user = new User("敏敏特穆尔", 0, 17, date, "你在哪，我就在哪！");
		UserDao userDao = new UserDaoImpl(this.sessionFactory);
		userDao.add(user);
		System.out.println("添加完成。。。");
	}

	@Test
	public void testDelete() {
		UserDao userDao = new UserDaoImpl(this.sessionFactory);
		userDao.delete(3);
		System.out.println("删除完成。。。");
	}

	@Test
	public void testGetById() {
		UserDao userDao = new UserDaoImpl(this.sessionFactory);
		User user = userDao.getById(11);
		System.out.println("根据主键查询：" + user);
	}

	@Test
	public void testGetByName() {
		UserDao userDao = new UserDaoImpl(this.sessionFactory);
		List<User> userList = userDao.getByName("%谢%");
		System.out.println("名称查询：" + userList);
	}

	@Test
	public void testUpdate() {
		UserDao userDao = new UserDaoImpl(this.sessionFactory);
		Date date = DateUtil.parseStrToFullDate("1073-11-20", "yyyy-MM-dd");
		User user = new User(12, "白眉鹰王", 1, 99, date, "鹰爪功！");
		userDao.update(user);
		System.out.println("更新完成。。。");
	}

}