1.配置模式
引入mybatis 的 pom.xml ,mybatis的官方starters的地址
<dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.2.0</version> </dependency>
观察MybatisAutoConfiguration里面有一个绑定类
@EnableConfigurationProperties({MybatisProperties.class}) //mybatis配置项绑定类
@AutoConfigureAfter({DataSourceAutoConfiguration.class, MybatisLanguageDriverAutoConfiguration.class})
其中MybatisProperties里面有绑定的是：@ConfigurationProperties(prefix = "mybatis")
而MybatisAutoConfiguration里面有定义的容器为SqlSessionFactory已经配置完成
@Bean @ConditionalOnMissingBean public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception { SqlSessionFactoryBean factory = new SqlSessionFactoryBean(); factory.setDataSource(dataSource); factory.setVfs(SpringBootVFS.class); if (StringUtils.hasText(this.properties.getConfigLocation())) { factory.setConfigLocation(this.resourceLoader.getResource(this.properties.getConfigLocation())); } this.applyConfiguration(factory); if (this.properties.getConfigurationProperties() != null) { factory.setConfigurationProperties(this.properties.getConfigurationProperties()); } if (!ObjectUtils.isEmpty(this.interceptors)) { factory.setPlugins(this.interceptors); } if (this.databaseIdProvider != null) { factory.setDatabaseIdProvider(this.databaseIdProvider); } if (StringUtils.hasLength(this.properties.getTypeAliasesPackage())) { factory.setTypeAliasesPackage(this.properties.getTypeAliasesPackage()); } if (this.properties.getTypeAliasesSuperType() != null) { factory.setTypeAliasesSuperType(this.properties.getTypeAliasesSuperType()); } if (StringUtils.hasLength(this.properties.getTypeHandlersPackage())) { factory.setTypeHandlersPackage(this.properties.getTypeHandlersPackage()); } if (!ObjectUtils.isEmpty(this.typeHandlers)) { factory.setTypeHandlers(this.typeHandlers); } if (!ObjectUtils.isEmpty(this.properties.resolveMapperLocations())) { factory.setMapperLocations(this.properties.resolveMapperLocations()); } Set<String> factoryPropertyNames = (Set)Stream.of((new BeanWrapperImpl(SqlSessionFactoryBean.class)).getPropertyDescriptors()).map(FeatureDescriptor::getName).collect(Collectors.toSet()); Class<? extends LanguageDriver> defaultLanguageDriver = this.properties.getDefaultScriptingLanguageDriver(); if (factoryPropertyNames.contains("scriptingLanguageDrivers") && !ObjectUtils.isEmpty(this.languageDrivers)) { factory.setScriptingLanguageDrivers(this.languageDrivers); if (defaultLanguageDriver == null && this.languageDrivers.length == 1) { defaultLanguageDriver = this.languageDrivers[0].getClass(); } } if (factoryPropertyNames.contains("defaultScriptingLanguageDriver")) { factory.setDefaultScriptingLanguageDriver(defaultLanguageDriver); } return factory.getObject(); }
其中也配置了SqlSession
@Bean @ConditionalOnMissingBean public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) { ExecutorType executorType = this.properties.getExecutorType(); return executorType != null ? new SqlSessionTemplate(sqlSessionFactory, executorType) : new SqlSessionTemplate(sqlSessionFactory); }
2.操作Mybatis
1.首先得有一个mybatis的全局配置文件,可在yaml中进行配置
根据官方文档的全局配置文件
<?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> <mappers> <mapper resource="org/mybatis/example/BlogMapper.xml"/> </mappers> </configuration>
因为springboot全部配置好了所以只需要
<?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> </configuration>
2.Mapper映射文件
<?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.sp.mapper.WholeMessage"> <!-- public Whole getWhole(Integer id);--> <select id="getWhole" resultType="com.sp.bean.Whole"> select * from whole where id = #{id} </select> </mapper>
3.对配置文件yaml进行配置
mybatis:
config-location: classpath:mybatis/mybatis-config.xml #mybatis文件夹下的xml全局配置文件
mapper-locations: classpth:mybatis/mapper/*.xml #mybatis文件夹下的mapper下的所有xml文件
配置mapper接口
package com.sp.mapper; import com.sp.bean.Whole; public interface WholeMapper { public Whole getWhole(Integer id); }
配置service类
package com.sp.service; import com.sp.bean.Whole; import com.sp.mapper.WholeMapper; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @Service public class WholeService { @Autowired WholeMapper wholeMapper; public Whole wholegetid(Integer id) { return wholeMapper.getWhole(id); } }
配置Controller类
@Autowired WholeService wholeService; @ResponseBody @GetMapping("/sqltest") public Whole getByid(@RequestParam("id") Integer id) { return wholeService.wholegetid(id); }
基于注解的方式
在mapper接口里的类中添加注解@select（“sql语句”）,其中的mybatis-config.xml以及mybaits文件下的mapper.xml文件也可以不用配置了
package com.sp.mapper; import com.sp.bean.Whole; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Select; @Mapper public interface WholeMapper { @Select("select * from whole where GOODS_ID = #{id}") public Whole getWhole(Integer id); }
注解模式和基本配置模式可以混搭使用
用注解的方式如果想要加上原配置版本的其他方法功能时可以再添加一个注解@Options
@Mapper public interface WholeMapper { @Select("select * from whole where GOODS_ID = #{id}") @Options(useGeneratedKeys = true,keyProperty = "GOODS_ID") //获取自增，字段名为GOODS_ID public Whole getWhole(Integer id); }
最佳实战
原文：https://www.cnblogs.com/YuyuFishSmile/p/14960784.html