1. Crie um novo projeto Maven
2. Importar dependências
<dependencies>
<dependency><!--单元测试-->
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.16</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.13</version>
</dependency>
</dependencies>
3. Escreva classes de entidade
@Data
public class Emp {
public int empid;
public String ename;
public String job;
public int mgr;
public Date hiredate;
public Double sal;
public Double comm;
public Integer deptno;
}
4. Grave o arquivo de mapeamento do mapeador.
De acordo com nosso hábito de usar integração Spring, armazenamos o arquivo do mapeador no diretório de recursos
<?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="com.tao.m1.mapper.EmpMapper">
<!--namespace:命名空间。目前取值没有要求,建议取当前文件的完整路径名,省略xml-->
<select id="selectAll" resultType="com.tao.m1.entity.Emp">
select * from emp
</select>
</mapper>
5. Grave o arquivo de configuração mybatis.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="mysql">
<environment id="mysql">
<!--配置事务管理器 -->
<transactionManager type="JDBC"></transactionManager>
<!-- 配置数据源-->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://192.168.0.177:3307/m_test?useSSL=false&useUnicode=true&characterEncoding=utf8&
serverTimezone=Asia/Shanghai"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<!--指明映射文件的位置。-->
<mappers>
<mapper resource="com/tao/m1/mapper/EmpMapper.xml"></mapper>
</mappers>
</configuration>
6. Use o junit para escrever o código de teste
public class TestMyBatis {
@Test
public void ss() throws IOException {
//创建SqlSessionFactory,会在src根路径下获取
InputStream is = Resources.getResourceAsStream("mybatis.xml");
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
//创建SqlSession
SqlSession session = factory.openSession();
System.out.println(session);
List<Emp> list =session.selectList("com.tao.m1.mapper.EmpMapper.selectAll");
System.out.println(list);
}
}
7. Execute o código de teste
Incluí a dependência de slf4j aqui, portanto, há instruções SQL para imprimir
8. Junte-se ao slf4j para imprimir o SQL
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.25</version>
<scope>test</scope>
</dependency>
9. Adicione o arquivo de configuração log4j.properties
#定义全局日志级别
log4j.rootLogger=error,stdout,logfile
#包级别日志
log4j.logger.com.tao.m1.mapper=debug
#接口级别日志
#log4j.logger.com.tao.m1.mapper.EmployeeMapper=debug
#方法级别日志
#log4j.logger.com.tao.m1.mapper.EmloyeeMapper.findBy=debug
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.err
log4j.appender.stdout.layout=org.apache.log4j.SimpleLayout
10. Estrutura completa do projeto