MyBatis（一）

kingbosster

　　一、Mybatis使用Maven构建
　　1.查找Maven的依赖地址
　　http://mvnrepository.com
　　https://repository.sonatype.org

<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>x.x.x</version>
</dependency>
从SqlSessionFactoryBuilder中获取SqlSessionFactory,在获取SqlSession
Mybatis-Config.xml
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="org/mybatis/example/BlogMapper.xml"/>
</mappers>
</configuration>
 
2.从SqlSessionFactory中获取SqlSession
SqlSession session = sqlSessionFactory.openSession();
try {
Blog blog = (Blog) session.selectOne("org.mybatis.example.BlogMapper.selectBlog", 101);
} finally {
session.close();
}
 但推荐使用一下方式
SqlSession session = sqlSessionFactory.openSession();
try {
BlogMapper mapper = session.getMapper(BlogMapper.class);
Blog blog = mapper.selectBlog(101);
} finally {
session.close();
}
 映射XML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="org.mybatis.example.BlogMapper">
<select id="selectBlog" resultType="Blog">
select * from Blog where id = #{id}
</select>
</mapper>
 命名空间namespace必须要有
注解
package org.mybatis.example;
public interface BlogMapper {
@Select("SELECT * FROM blog WHERE id = #{id}")
Blog selectBlog(int id);
}