Spring入门（四）——整合Mybatis

---

1. 准备jar包及目录结构

2. 配置db.properties

driver = com.mysql.jdbc.Driver
url = jdbc:mysql://127.0.0.1:3306/Howl
name = root
password =

3. 配置applicationContext.xml

<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:db.properties" />

<!--spring自带数据源,没有连接池功能 -->
<!-- <bean id="DataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${driver}"></property>
    <property name="url" value="${url}"></property>
    <property name="username" value="${name}"></property>
    <property name="password" value="${password}"></property>
</bean> -->

<!-- c3p0数据源，推荐 -->
<bean id="DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    <property name="driverClass" value="${driver}"/>
    <property name="jdbcUrl" value="${url}"/>
    <property name="user" value="${name}"/>
    <property name="password" value="${password}"/>
</bean>

<!-- 配置SqlSessionFactory,加载mybaits配置文件和映射文件 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
	<property name="configLocation" value="classpath:mybatis.xml"/>
	<property name="dataSource" ref="DataSource"/>
</bean>

4. 创建Bean对象

package bean;

public class User {

	private int id;
	private String name;
	private String password;

	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 String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", password=" + password + "]";
	}
}

5. 配置Mapper.xml文件（Mapper代理方式）

<mapper namespace="com.howl.UserMapper">

	<!-- 通过id查询用户 -->
    <select id="findUserById" parameterType="Integer" resultType="bean.User">
    	select * from user where id = #{id}
    </select>

</mapper>

6. 代理接口

package com.howl;

public interface UserMapper {

	public User findUserById(int id);

}

7. 配置Mybatis.xml

<!-- 根标签 -->
<configuration>

	<!-- 引入mapper文件的位置 -->
	<mappers>
		<mapper resource="Mapper/UserMapper.xml"/>
	</mappers>

</configuration>

8. 测试

//获取sqlSession
ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
SqlSessionFactory sqlSessionFactory = (SqlSessionFactory ) ac.getBean("sqlSessionFactory");
SqlSession sqlSession = sqlSessionFactory.openSession();

//获取代理对象
UserMapper userMapper = sqlSession.getMapper(com.howl.UserMapper.class);
User user = userMapper.findUserById(46);

//打印Bean对象
System.out.println(user);

9. 打印

<!-- 整合成功 -->
<!-- 十二月 04, 2019 8:30:35 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource -->

User [id=46, name=123123, password=123123]