compile group: 'org.mybatis', name: 'mybatis', version: '3.4.2'
  compile group: 'org.mybatis', name: 'mybatis-typehandlers-jsr310', version: '1.0.2'
  compile group: 'mysql', name: 'mysql-connector-java', version: '5.1.40'

  <?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>
    <!--指定属性-->
    <properties>
      <property name="driver" value="com.mysql.jdbc.Driver"/>
      <property name="url" value="jdbc:mysql://localhost:3306/test"/>
      <property name="username" value="root"/>
      <property name="password" value="12345678"/>
      <property name="driver.useSSL" value="false"/>
    </properties>
    <!--系统设置-->
    <settings>
      <setting name="cacheEnabled" value="true"/>
      <setting name="lazyLoadingEnabled" value="true"/>
    </settings>
    <!--指定简写名-->
    <typeAliases>
      <package name="yitian.study.entity"/>
    </typeAliases>
    <!--配置环境，可以配置多个环境用于测试、调试和生产-->
    <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>
    <!--配置映射文件-->
    <mappers>
      <mapper resource="BaseEntityMapper.xml"/>
    </mappers>
  </configuration>

 public abstract class MyBatisUtils {
    private static volatile SqlSessionFactory sqlSessionFactory;
    public static final String MyBatisConfigLocation = "configuration.xml";
    public static SqlSessionFactory getSqlSessionFactory() throws IOException {
      if (sqlSessionFactory == null) {
        synchronized (MyBatisUtils.class) {
          if (sqlSessionFactory == null) {
            InputStream input = Resources.getResourceAsStream(MyBatisConfigLocation);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(input);
            input.close();
          }
        }
      }
      return sqlSessionFactory;
    }
  }

 public class Person {
    private int id;
    private String username;
    private LocalDate birthday;
  }

 CREATE TABLE person (
   id    INT AUTO_INCREMENT PRIMARY KEY,
   username VARCHAR(255) NOT NULL UNIQUE,
   birthday DATE
  );

 <?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="yitian.study.dao.mapper">
    <select id="selectPerson"
        resultType="Person" parameterType="Person">
      SELECT *
      FROM Person
      WHERE id = #{id}
    </select>
    <select id="selectPersonByName"
        resultType="Person">
      SELECT *
      FROM Person
      WHERE username = #{username}
    </select>
    <insert id="insertPerson"
        useGeneratedKeys="true">
      INSERT INTO Person (username, birthday) VALUES (#{username}, #{birthday})
    </insert>
    <update id="updatePerson">
      UPDATE Person
      SET birthday = #{birthday}
      WHERE id = #{id}
    </update>
    <delete id="deletePerson">
      DELETE FROM Person
      WHERE id = #{id}
    </delete>
  </mapper>

 import static org.assertj.core.api.Assertions.*;
  public class MyBatisTest {
    private static SqlSessionFactory sqlSessionFactory;
    private SqlSession sqlSession;
    @BeforeClass
    public static void init() throws IOException {
      sqlSessionFactory = MyBatisUtils.getSqlSessionFactory();
    }
    @Before
    public void before() {
      sqlSession = sqlSessionFactory.openSession(true);//自动提交
    }
    @After
    public void after() {
      sqlSession.close();
    }
    @Test
    public void testMyBatisUtils() {
      assertThat(sqlSessionFactory).isNotNull();
    }
    @Test
    public void testInsert() {
      Person p = new Person(0, "yitian", LocalDate.of(1993, 5, 6));
      sqlSession.insert("insertPerson", p);
      Person s = sqlSession.selectOne("selectPersonByName", p.getUsername());
      assertThat(s).isNotNull();
      System.out.println(s);
      sqlSession.delete("deletePerson", s);
    }
    @Test
    public void testUpdate() {
      Person p = new Person(1, "leo", LocalDate.of(1993, 5, 6));
      sqlSession.insert("insertPerson", p);
      p = sqlSession.selectOne("selectPersonByName", p.getUsername());
      LocalDate b = LocalDate.of(1987, 7, 8);
      p.setBirthday(b);
      sqlSession.update("updatePerson", p);
      Person s = sqlSession.selectOne("selectPersonByName", p.getUsername());
      assertThat(s.getBirthday()).isEqualTo(b);
      System.out.println(s);
      sqlSession.delete("deletePerson", s);
    }
  }

public interface PersonMapper {
    Person selectPerson(int id);
    Person selectPersonByName(String name);
    void insertPerson(Person person);
    void updatePerson(Person person);
    void deletePerson(Person person);
  }

<mapper namespace="yitian.study.mapper.PersonMapper">

 PersonMapper mapper = sqlSession.getMapper(PersonMapper.class);
  Person p = new Person(0, "yitian", LocalDate.of(1993, 5, 6));
  mapper.insertPerson(p);
  Person s = mapper.selectPersonByName(p.getUsername());
  assertThat(s).isNotNull();
  System.out.println(s);
  mapper.deletePerson(p);