mybatis源码环境搭建

MyTest.java

  @Test
  public void test() {
    String resource = "mybatis-config.xml";
    InputStream inputStream = null;
    try {
      inputStream = Resources.getResourceAsStream(resource);
    } catch (IOException e) {
      e.printStackTrace();
    }
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

    SqlSession sqlSession = sqlSessionFactory.openSession();

    UserMapper userMapper = sqlSession.getMapper(UserMapper.class);

//    List<User> users = userMapper.selectUsers();
//
//    System.out.println(users);

    User user = userMapper.selectUser(1);
    System.out.println(user);
  }

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>
  <properties>
    <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/test"/>
    <property name="username" value="root"/>
    <property name="password" value="1226abcd"/>
  </properties>

  <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="mappers/userMapper.xml"/>
  </mappers>
</configuration>

userMapper.xml

<?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.apache.ibatis.myTest.mapper.UserMapper">

  <select id="selectUsers" resultType="org.apache.ibatis.myTest.entity.User">
    select * from user
  </select>


  <select id="selectUser" resultType="org.apache.ibatis.myTest.entity.User">
    select * from user
    <where>
      <if test="id != null ">
        and id = #{id}
      </if>
    </where>
  </select>
</mapper>

UserMapper.java

public interface UserMapper {
  List<User> selectUsers();

  User selectUser(@Param(value = "id") Integer id);
}

User.java

public class User {
  private Integer id;

  private String name;

  private Integer age;

  public Integer getId() {
    return id;
  }

  public void setId(Integer id) {
    this.id = id;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Integer getAge() {
    return age;
  }

  public void setAge(Integer age) {
    this.age = age;
  }

  @Override
  public String toString() {
    return "User{" +
      "id=" + id +
      ", name='" + name + '\'' +
      ", age=" + age +
      '}';
  }
}