Mybatis入门程序

1. 下载jar包

https://github.com/mybatis/mybatis-3/releases

2. 导入jar包

• mybatis -3.2.7.jar
• lib目录下所有jar包
• mysql驱动包

image.png

3. classpath目录下创建log4j.properties

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

4. classpath下创建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>
  <!-- 和spring整合后 environments配置将废除-->
  <environments default=*"development"*>
  <environment id=*"development"*>
  <!-- 使用jdbc事务管理-->
  <transactionManager type=*"JDBC"* />
 <!-- 数据库连接池-->
  <dataSource type="POOLED">
  <property name="driver" value="com.mysql.jdbc.Driver" />
  <property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8" />
  <property name="username" value="root" />
  <property name="password" value="root" />
  </dataSource>
  </environment>
  </environments>
</configuration>

5. 编写po类（bean类）

Public class User {

  private int id;
  private String username;// 用户姓名
  private String sex;// 性别
  //get/set方法

6. 创建sql映射文件User.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=*"test"*>
    <select id="getUserById" parameterType="java.lang.Integer" resultType="com.itheima.pojo.User">
        select * from user where id = #{id}
    </select>
</mapper>

并在SqlMapConfig.xml配置

<mappers>
        <mapper resource="sqlmap/User.xml"/>
</mappers>

7. 测试程序

public class Demo1 {

    private SqlSessionFactory factory;
    @Before
    public void setUp() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        this.factory = new SqlSessionFactoryBuilder().build(inputStream);
    }
    
    @Test
    public void run1() throws IOException {
        SqlSession session = this.factory.openSession();
        User user = session.selectOne("test.getUserById" , 1);
        System.out.println(user);
    }

初步的快速入门完成！