mybatis学习笔记(1)基本环境 1.pom引入 2. config配置。在resource下添加 mybatis-config.xml 3.添加开发需要的mapper,实体类 4.整体目录结构 5.运行main方法。 6.执行并打印。
<dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.1</version> </dependency> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.17</version> </dependency> </dependencies>
2. config配置。在resource下添加 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 > <transactionManager type="JDBC"/> <!-- 配置数据库连接信息 --> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value=""/> <property name="username" value=""/> <property name="password" value=""/> </dataSource> </environment> </environments> <mappers> <!-- 添加映射文件到Mybatis的全局配置文件中 --> <mapper resource="learn/mybatis/CarrierMapper.xml"/> </mappers> </configuration>
3.添加开发需要的mapper,实体类
CarrierMapper.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"> <!-- namespace:名称空间 id:唯一标识 resultType:返回值类型 #{id}:从传过来的参数中取出id值 --> <mapper namespace="learn.mybatis.CarrierMapper"> <select > select id, carrier_no carrierNo, carrier_name carrierName, main_page mainPage from t_carrier where is_deleted = 0 </select> </mapper>
CarrierMapper.java
package learn.mybatis; import java.util.List; /** * Create by tianqing on 2019/7/24. */ public interface CarrierMapper { List<Carrier> queryAll(); }
Carrier.java
public class Carrier { private Long id; private String carrierNo; private String carrierName; private String mainPage; /** * 承运商类型 */ private Integer carrierType; private Integer isDeleted; private String creator; private String editor; private Date createTime; private Date editTime;
getset... }
4.整体目录结构
5.运行main方法。
package learn.mybatis; import com.google.gson.Gson; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.InputStream; import java.util.List; /** * Create by tianqing on 2019/7/23. */ public class MybatisLearn { private static final Logger logger = LoggerFactory.getLogger(MybatisLearn.class); public static void main(String[] args) throws Exception { //前三步都相同 InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml"); SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream); SqlSession sqlSession = factory.openSession(); //这里不再调用SqlSession 的api,而是获得了接口对象,调用接口中的方法。 CarrierMapper mapper = sqlSession.getMapper(CarrierMapper.class); List<Carrier> carriers = mapper.queryAll(); Gson gson = new Gson(); logger.info("[MybatisLearn - main] 结果:{}", gson.toJson(carriers)); } }
6.执行并打印。
跑起来以后。我们不着急多种用法,下一章大致研究下 mybatis怎么实现的