springboot2 + mybatis 多種方式實現多數據配置
- 2020 年 3 月 29 日
- 筆記
業務系統複雜程度增加，為了解決數據庫I/O瓶頸，很自然會進行拆庫拆表分服務來應對。這就會出現一個系統中可能會訪問多處數據庫，需要配置多個數據源。
第一種場景：項目服務從其它多處數據庫取基礎數據進行業務處理，因此各庫之間不會出現重表等情況。
第二種場景：為了減輕寫入壓力進行讀寫分庫，讀走從庫，寫為主庫。此種表名等信息皆為一致。
第三種場景：以上兩種皆有。對於某些業務需要大數據量的匯總統計，希望不影響正常業務必須走從庫（表信息一致），某些配置信息不存在讀寫壓力，出現不分庫（表信息不一致）
項目源代碼：
https://github.com/zzsong/springboot-multiple-datasource.git
有三個目錄：
one:
直接使用多@Bean配置，@MapperScan來路徑區分讀何庫
two:
使用註解的方式來標識走何dataSource,AOP攔截注入動態數據源
third:
使用spring的Bean命名策略進行區分數據來源
項目技術選型： springBoot2.2.5 + mybatis + druid + mysql
先看主要的pom包
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.5.RELEASE</version> <relativePath/> </parent> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.1.2</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.19</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.21</version> </dependency>
application.yml
spring: datasource: druid: core: url: jdbc:mysql:///kc_core?characterEncoding=utf-8&serverTimezone=Asia/Shanghai username: root password: 123456 driver-class-name: com.mysql.cj.jdbc.Driver type: com.alibaba.druid.pool.DruidDataSource schedule: url: jdbc:mysql:///kc_schedule?characterEncoding=utf-8&serverTimezone=Asia/Shanghai username: root password: 123456 driver-class-name: com.mysql.cj.jdbc.Driver type: com.alibaba.druid.pool.DruidDataSource
mysql新版本必須帶有serverTimezone，不然會報連接異常。
第一種：通過@MapperScans 掃描匹配相關的數據源
@Configuration @MapperScans({ @MapperScan(basePackages = "com.zss.one.mapper.core", sqlSessionTemplateRef = "coreSqlSessionTemplate",sqlSessionFactoryRef = "coreSqlSessionFactory"), @MapperScan(basePackages = "com.zss.one.mapper.schedule", sqlSessionTemplateRef = "scheduleSqlSessionTemplate",sqlSessionFactoryRef = "scheduleSqlSessionFactory") }) public class MybatisOneConfig { @Bean @ConfigurationProperties(prefix = "spring.datasource.druid.core") public DataSource coreDataSource(){ return DruidDataSourceBuilder.create().build(); } @Bean public SqlSessionFactory coreSqlSessionFactory(@Qualifier("coreDataSource") DataSource coreDataSource) throws Exception { SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean(); sessionFactory.setDataSource(coreDataSource); sessionFactory.getObject().getConfiguration().setJdbcTypeForNull(null); sessionFactory.getObject().getConfiguration().setMapUnderscoreToCamelCase(true); return sessionFactory.getObject(); } @Bean public SqlSessionTemplate coreSqlSessionTemplate(@Qualifier("coreSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception { return new SqlSessionTemplate(sqlSessionFactory); } //======schedule======== @Bean @ConfigurationProperties(prefix = "spring.datasource.druid.schedule") public DataSource scheduleDataSource(){ return DruidDataSourceBuilder.create().build(); } @Bean public SqlSessionFactory scheduleSqlSessionFactory(@Qualifier("scheduleDataSource") DataSource coreDataSource) throws Exception { SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean(); sessionFactory.setDataSource(coreDataSource); sessionFactory.getObject().getConfiguration().setJdbcTypeForNull(null); sessionFactory.getObject().getConfiguration().setMapUnderscoreToCamelCase(true); return sessionFactory.getObject(); } @Bean public SqlSessionTemplate scheduleSqlSessionTemplate(@Qualifier("scheduleSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception { return new SqlSessionTemplate(sqlSessionFactory); } }
第二種是動態數據源模式，通過AOP切入註解引導使用何數據源。用自定義註解@interface來標識方法走對應的數據源。
注意事項：類中的方法再調用帶數據源的方法，不能被AOP切入
@Target({ElementType.METHOD, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface TargetDataSource { String value(); }
extends spring的動態DataSource路由來匹配
public class DynamicDataSource extends AbstractRoutingDataSource { @Override protected Object determineCurrentLookupKey() { return DataSourceContextRouting.getDataSourceName(); } }
@Configuration //@EnableConfigurationProperties(MybatisProperties.class)//不要使用此公共配置，Configuration會破壞相關dataSource的配置 @MapperScan("com.zss.two.mapper") public class MybatisConfig { @Bean @ConfigurationProperties(prefix = "spring.datasource.druid.core") public DataSource coreDataSource() { return DruidDataSourceBuilder.create().build(); } @Bean @ConfigurationProperties(prefix = "spring.datasource.druid.schedule") public DataSource scheduleDataSource() { return DruidDataSourceBuilder.create().build(); } @Autowired @Qualifier("coreDataSource") private DataSource coreDataSource; @Autowired @Qualifier("scheduleDataSource") private DataSource scheduleDataSource; @Bean public DynamicDataSource dataSource() { Map<Object, Object> targetDataSources = new HashMap<>(); targetDataSources.put(DataSourceConstants.CORE_DATA_SOURCE, coreDataSource); targetDataSources.put(DataSourceConstants.SCHEDULE_DATA_SOURCE, scheduleDataSource); DynamicDataSource dataSource = new DynamicDataSource(); //設置數據源映射 dataSource.setTargetDataSources(targetDataSources); //// 設置默認數據源，當無法映射到數據源時會使用默認數據源 dataSource.setDefaultTargetDataSource(coreDataSource); dataSource.afterPropertiesSet(); return dataSource; } /** * 根據數據源創建SqlSessionFactory */ @Bean public SqlSessionFactory sqlSessionFactory(DynamicDataSource dataSource) throws Exception { SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean(); sessionFactory.setDataSource(dataSource); sessionFactory.getObject().getConfiguration().setJdbcTypeForNull(null); sessionFactory.getObject().getConfiguration().setMapUnderscoreToCamelCase(true); return sessionFactory.getObject(); } @Bean public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) throws Exception { return new SqlSessionTemplate(sqlSessionFactory); }
第三種，自定義Bean命名策略，按beanName進行自動匹配使用數據源
@Component public class CoreBeanNameGenerator implements BeanNameGenerator { @Override public String generateBeanName(BeanDefinition definition, BeanDefinitionRegistry registry) { return "core"+ ClassUtils.getShortName(definition.getBeanClassName()); } } @Component public class ScheduleBeanNameGenerator implements BeanNameGenerator { @Override public String generateBeanName(BeanDefinition definition, BeanDefinitionRegistry registry) { return "schedule"+ ClassUtils.getShortName(definition.getBeanClassName()); } }
使用mybatis MapperScannerConfigurer自動掃描，將Mapper接口生成注入到spring
@Bean public MapperScannerConfigurer coreMapperScannerConfig(CoreBeanNameGenerator coreBeanNameGenerator){ MapperScannerConfigurer configurer = new MapperScannerConfigurer(); configurer.setNameGenerator(coreBeanNameGenerator); configurer.setBasePackage("com.zss.third.mapper.core,com.zss.third.mapper.order"); configurer.setSqlSessionFactoryBeanName("coreSqlSessionFactory"); configurer.setSqlSessionTemplateBeanName("coreSqlSessionTemplate"); return configurer; } @Bean public MapperScannerConfigurer scheduleMapperScannerConfig(ScheduleBeanNameGenerator scheduleBeanNameGenerator){ MapperScannerConfigurer configurer = new MapperScannerConfigurer(); configurer.setNameGenerator(scheduleBeanNameGenerator); configurer.setBasePackage("com.zss.third.mapper.schedule,com.zss.third.mapper.order"); configurer.setSqlSessionFactoryBeanName("scheduleSqlSessionFactory"); configurer.setSqlSessionTemplateBeanName("scheduleSqlSessionTemplate"); return configurer; }
到此，三種多數據源匹配主要點介紹完，詳細直接下載github項目。 在resources/db含有相關測試表及數據腳本。
