<dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.7</version>
    </dependency>

2.在utils目錄下目錄下建立一個MybatisUtils類，通過這個工具類獲得一個sqlSession.

public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    //既然有了 SqlSessionFactory，顧名思義，我們可以從中獲得 SqlSession 的例項。
    // SqlSession 提供了在資料庫執行 SQL 命令所需的所有方法
    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession();
    }
}
 

3.在resources目錄下新增對 MyBatis 系統的核心設定的XML 配置檔案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>

  <!--每寫一個介面實現xml檔案，都需要在這裡配置相應的xml路徑，現在先不寫
  <mappers>
    <mapper resource="org/mybatis/builder/AuthorMapper.xml"/>
    <mapper resource="org/mybatis/builder/BlogMapper.xml"/>
    <mapper resource="org/mybatis/builder/PostMapper.xml"/>
  </mappers>
  -->
</configuration>
 

4.在resources目錄下新增一個db.properties檔案，進行資料庫的配置,

driver=org.postgresql.Driver
url=jdbc:postgresql://localhost:5432/postgres
username=username
password=123456

並在mybatis-config.xml中新增

5.在dao目錄下建立對應的介面和實現類。不過使用了Mybatis後，用xml檔案代替原來的實現類，這個檔案頭為

<?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">

<!--namespace指向的是dao介面檔案的路徑-->
<mapper namespace="org.mybatis.example.BlogMapper">
<!--id指向介面的方法名，resultType指向pojo包下的類名路徑-->
  <select id="selectBlog" resultType="Blog">
    select * from Blog where id = #{id}
  </select>
</mapper>
 

6.測試函式

public void text() {
        //第一步獲取SqlSession物件
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //方法一
        //第二步執行SQL語句
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.getUserList();
        //方法二
        //淘汰了//List<User> userList=sqlSession.selectList("com.huang.dao.UserDao.getUserList");
        for (User user : userList) {
            System.out.println(user);
        }
        //關閉資源
        sqlSession.close();
    }