使用Mapper方式操作数据库

创建全局配置文件

SqlMapConfig.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">
            <!-- 配置JDBC事务控制，由mybatis进行管理 -->
            <transactionManager type="JDBC"></transactionManager>
            <!-- 配置数据源，采用mybatis连接池 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/ee19_batis_day03?useUnicode=true&amp;characterEncoding=utf-8" />
                <property name="username" value="root" />
                <property name="password" value="123" />
            </dataSource>
        </environment>
    </environments>

    <!-- 加载映射文件 -->
    <mappers>
        <mapper resource="mapper/UserMapper.xml"></mapper>
    </mappers>
</configuration>

创建实体类Mapper接口

package mapper;

import test.User;

public interface UserMapper {
    User findUserById(int id) throws Exception;

    void insertUser(User user) throws Exception;

}

创建Mapper的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="mapper.UserMapper">

    <select id="findUserById" parameterType="int"
            resultType="test.User">
		SELECT * FROM USER WHERE id = #{id}
	</select>

    <insert id="insertUser" parameterType="test.User">
        <selectKey keyProperty="id" resultType="int" order="AFTER">
            SELECT LAST_INSERT_ID()
        </selectKey>
        INSERT INTO USER
        (username,birthday,sex,address)
        VALUES(#{username},#{birthday},#{sex},#{address})
    </insert>

</mapper>

测试

@Test
    public void testMapper() throws Exception {
        //读取配置文件
        //全局配置文件的路径
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);

        //创建SqlSessionFactory
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        //创建SqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = mapper.findUserById(29);
        System.out.println("user = " + user);

        User user1 = new User();
        user1.setUsername("chaoge111");
        user1.setAddress("shenyang");
        user1.setSex("1");
        mapper.insertUser(user1);
        System.out.println("user1.getId() = " + user1.getId());

        sqlSession.commit();
        sqlSession.close();
    }

工程结构