spring boot 配置多数据源（Spring Boot 多数据源配置）

第一种方式： AbstractRoutingDataSource

1.1. 手动切换数据源

application.properties

# Order # 如果用Druid作为数据源    
    
 ，应该用url属性     


     


     ，而不是jdbc-url spring.datasource.order.jdbc-url=jdbc:mysql://localhost:3306/order?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false spring.datasource.order.username=root spring.datasource.order.password=123456 spring.datasource.order.driver-class-name=com.mysql.cj.jdbc.Driver # Stock spring.datasource.stock.jdbc-url=jdbc:mysql://localhost:3306/stock?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false spring.datasource.stock.username=root spring.datasource.stock.password=123456 spring.datasource.stock.driver-class-name=com.mysql.cj.jdbc.Driver # Account spring.datasource.account.jdbc-url=jdbc:mysql://localhost:3306/account?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false spring.datasource.account.username=root spring.datasource.account.password=123456 spring.datasource.account.driver-class-name=com.mysql.cj.jdbc.Driver

配置数据源

DataSourceConfig.java

package com.cjs.example.config; import com.alibaba.druid.pool.DruidDataSource; import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean; import com.zaxxer.hikari.HikariDataSource; import org.mybatis.spring.SqlSessionFactoryBean; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.boot.jdbc.DataSourceBuilder; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import javax.sql.DataSource; import java.util.HashMap; import java.util.Map; @Configuration public class DataSourceConfig { @Bean("orderDataSource") @ConfigurationProperties(prefix = "spring.datasource.order") public DataSource orderDataSource() { // return new HikariDataSource(); // return new DruidDataSource(); return DataSourceBuilder.create().build(); } @Bean("accountDataSource") @ConfigurationProperties(prefix = "spring.datasource.account") public DataSource accountDataSource() { // return new HikariDataSource(); // return new DruidDataSource(); return DataSourceBuilder.create().build(); } @Bean("stockDataSource") @ConfigurationProperties(prefix = "spring.datasource.stock") public DataSource stockDataSource() { // return new HikariDataSource(); // return new DruidDataSource(); return DataSourceBuilder.create().build(); } @Primary @Bean("dynamicDataSource") public DataSource dynamicDataSource(@Qualifier("orderDataSource") DataSource orderDataSource, @Qualifier("accountDataSource") DataSource accountDataSource, @Qualifier("stockDataSource") DataSource stockDataSource) { Map<Object, Object> dataSourceMap = new HashMap<>(3); dataSourceMap.put(DataSourceKey.ORDER.name(), orderDataSource); dataSourceMap.put(DataSourceKey.STOCK.name(), stockDataSource); dataSourceMap.put(DataSourceKey.ACCOUNT.name(), accountDataSource); DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource(); dynamicRoutingDataSource.setDefaultTargetDataSource(orderDataSource); dynamicRoutingDataSource.setTargetDataSources(dataSourceMap); return dynamicRoutingDataSource; } /* https://baomidou.com/pages/3b5af0/ */ @Bean public MybatisSqlSessionFactoryBean sqlSessionFactoryBean(@Qualifier("dynamicDataSource") DataSource dataSource) { MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean(); sqlSessionFactoryBean.setDataSource(dataSource); // sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/*.xml")); return sqlSessionFactoryBean; } }

由于是MyBatsi-Plus




 




 




，所以配的是MybatisSqlSessionFactoryBean
   

   

，如果是MyBatis     

     

     ，则应该是SqlSessionFactoryBean

DataSourceKey.java

package com.cjs.example.config; public enum DataSourceKey { /** * Order data source key. */ ORDER, /** * Stock data source key. */ STOCK, /** * Account data source key. */ ACCOUNT }

DynamicDataSourceContextHolder.java

package com.cjs.example.config; public class DynamicDataSourceContextHolder { private static final ThreadLocal<String> CONTEXT_HOLDER = ThreadLocal.withInitial(DataSourceKey.ORDER::name); public static void setDataSourceKey(DataSourceKey key) { CONTEXT_HOLDER.set(key.name()); } public static String getDataSourceKey() { return CONTEXT_HOLDER.get(); } public static void clearDataSourceKey() { CONTEXT_HOLDER.remove(); } }

DynamicRoutingDataSource.java

package com.cjs.example.config; import lombok.extern.slf4j.Slf4j; import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource; @Slf4j public class DynamicRoutingDataSource extends AbstractRoutingDataSource { @Override protected Object determineCurrentLookupKey() { log.info("当前数据源 [{}]", DynamicDataSourceContextHolder.getDataSourceKey()); return DynamicDataSourceContextHolder.getDataSourceKey(); } }

好了 




  




  



，配置完以后

  


  


，在操作数据库之前     
     
    ，先设置用哪个数据源即可  




   




   


，就像下面这样：

DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ACCOUNT);

举个例子：

package com.cjs.example; import com.cjs.example.account.entity.Account; import com.cjs.example.account.service.IAccountService; import com.cjs.example.config.DataSourceKey; import com.cjs.example.config.DynamicDataSourceContextHolder; import com.cjs.example.order.entity.Order; import com.cjs.example.order.service.IOrderService; import com.cjs.example.stock.entity.Stock; import com.cjs.example.stock.service.IStockService; import org.junit.jupiter.api.Test; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.context.SpringBootTest; import java.math.BigDecimal; @SpringBootTest public class Demo1122ApplicationTests { @Autowired private IOrderService orderService; @Autowired private IAccountService accountService; @Autowired private IStockService stockService; @Test public void doBusiness() { DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ORDER); Order order = new Order(); order.setOrderNo("123"); order.setUserId("1"); order.setCommodityCode("abc"); order.setCount(1); order.setAmount(new BigDecimal("9.9")); orderService.save(order); DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.STOCK); Stock stock = new Stock(); stock.setId(1); stock.setCommodityCode("abc"); stock.setName("huawei"); stock.setCount(1); stockService.updateById(stock); DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ACCOUNT); Account account = new Account(); account.setId(1); account.setUserId("1"); account.setAmount(new BigDecimal(100)); accountService.updateById(account); } }

这样写看起来确实有些麻烦


 



 



，通常可能不会像这样在一个方法里操作多个数据库             ，就比如说假设这是一个管理后台   




    




    

，为了图省事把所有业务都写在这一个项目里













，这个时候就需要配置多个数据源            ，各个数据库的业务互相没有关联    



     



     
，只是写在同一个项目中而已














，这样的话如果每次都手动设置数据源太麻烦    
    
 ，可以定义一个AOP切面来自动切换数据源    
    
    
。

1.2. 自动切换数据源

https://docs.spring.io/spring-framework/docs/current/reference/html/core.html#aop-ataspectj

給刚才的代码升个级     


     


     ，利用AOP来拦截目标方法自动切换数据源

1    
    
    
、添加@EnableAspectJAutoProxy注解

package com.cjs.example; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.EnableAspectJAutoProxy; @EnableAspectJAutoProxy @MapperScan("com.cjs.example.*.mapper") @SpringBootApplication public class Demo1122Application { public static void main(String[] args) { SpringApplication.run(Demo1122Application.class, args); } }

2


     


     


 、定义切面
 




 




 、切点   

   

   

、通知

package com.cjs.example.aop; import com.cjs.example.config.DataSourceKey; import com.cjs.example.config.DynamicDataSourceContextHolder; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.springframework.stereotype.Component; @Aspect @Component public class DataSourceAdvice { // @Pointcut("within(com.cjs.example.order..*)") @Pointcut("execution(* com.cjs.example.order..*.*(..))") public void orderPointcut() {} // @Pointcut("within(com.cjs.example.account..*)") @Pointcut("execution(* com.cjs.example.account..*.*(..))") public void accountPointcut() {} // @Pointcut("within(com.cjs.example.stock..*)") @Pointcut("execution(* com.cjs.example.stock..*.*(..))") public void stockPointcut() {} @Around("orderPointcut()") public Object order(ProceedingJoinPoint pjp) throws Throwable { DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ORDER); Object retVal = pjp.proceed(); DynamicDataSourceContextHolder.clearDataSourceKey(); return retVal; } @Around("accountPointcut()") public Object account(ProceedingJoinPoint pjp) throws Throwable { DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ACCOUNT); Object retVal = pjp.proceed(); DynamicDataSourceContextHolder.clearDataSourceKey(); return retVal; } @Around("stockPointcut()") public Object stock(ProceedingJoinPoint pjp) throws Throwable { DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.STOCK); Object retVal = pjp.proceed(); DynamicDataSourceContextHolder.clearDataSourceKey(); return retVal; } }

现在就不用每次调用service方法前手动设置数据源了

工程结构

第二种方式：dynamic-datasource-spring-boot-starter

功能很强大




 




 




，支持 数据源分组
   

   

，适用于多种场景 纯粹多库 读写分离 一主多从 混合模式

https://github.com/baomidou/dynamic-datasource-spring-boot-starter

1 

     

     

、引入dynamic-datasource-spring-boot-starter

<dependency> <groupId>com.baomidou</groupId> <artifactId>dynamic-datasource-spring-boot-starter</artifactId> <version>3.5.2</version> </dependency>

2

  




  




  、配置数据源

spring: datasource: dynamic: primary: master #设置默认的数据源或者数据源组,默认值即为master strict: false #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源 datasource: master: url: jdbc:mysql://xx.xx.xx.xx:3306/dynamic username: root password: 123456 driver-class-name: com.mysql.jdbc.Driver # 3.2.0开始支持SPI可省略此配置 slave_1: url: jdbc:mysql://xx.xx.xx.xx:3307/dynamic username: root password: 123456 driver-class-name: com.mysql.jdbc.Driver slave_2: url: ENC(xxxxx) # 内置加密,使用请查看详细文档 username: ENC(xxxxx) password: ENC(xxxxx) driver-class-name: com.mysql.jdbc.Driver #......省略 #以上会配置一个默认库master     

     

     ，一个组slave下有两个子库slave_1,slave_2

主从配置 




  




  



，读写分离

# 多主多从 纯粹多库（记得设置primary） 混合配置 spring: spring: spring: datasource: datasource: datasource: dynamic: dynamic: dynamic: datasource: datasource: datasource: master_1: mysql: master: master_2: oracle: slave_1: slave_1: sqlserver: slave_2: slave_2: postgresql: oracle_1: slave_3: h2: oracle_2:

改造一下前面的例子

spring.datasource.dynamic.primary=order # Order spring.datasource.dynamic.datasource.order.url=jdbc:mysql://localhost:3306/order?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false spring.datasource.dynamic.datasource.order.username=root spring.datasource.dynamic.datasource.order.password=123456 spring.datasource.dynamic.datasource.order.driver-class-name=com.mysql.cj.jdbc.Driver # Stock spring.datasource.dynamic.datasource.stock.url=jdbc:mysql://localhost:3306/stock?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false spring.datasource.dynamic.datasource.stock.username=root spring.datasource.dynamic.datasource.stock.password=123456 spring.datasource.dynamic.datasource.stock.driver-class-name=com.mysql.cj.jdbc.Driver # Account spring.datasource.dynamic.datasource.account.url=jdbc:mysql://localhost:3306/account?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false spring.datasource.dynamic.datasource.account.username=root spring.datasource.dynamic.datasource.account.password=123456 spring.datasource.dynamic.datasource.account.driver-class-name=com.mysql.cj.jdbc.Driver

3  


  


  

、使用@DS切换数据源

@DS可以注解在方法上或类上

  


  


，同时存在就近原则 方法上注解 优先于 类上注解

注解 结果 没有@DS 默认数据源 @DS("dsName")   dsName可以为组名也可以为具体某个库的名称 package com.cjs.example.order.service.impl; import com.baomidou.dynamic.datasource.annotation.DS; import com.cjs.example.order.entity.Order; import com.cjs.example.order.mapper.OrderMapper; import com.cjs.example.order.service.IOrderService; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import org.springframework.stereotype.Service; @DS("order") @Service public class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements IOrderService { } package com.cjs.example.stock.service.impl; import com.baomidou.dynamic.datasource.annotation.DS; import com.cjs.example.stock.entity.Stock; import com.cjs.example.stock.mapper.StockMapper; import com.cjs.example.stock.service.IStockService; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import org.springframework.stereotype.Service; @DS("stock") @Service public class StockServiceImpl extends ServiceImpl<StockMapper, Stock> implements IStockService { } package com.cjs.example.account.service.impl; import com.baomidou.dynamic.datasource.annotation.DS; import com.cjs.example.account.entity.Account; import com.cjs.example.account.mapper.AccountMapper; import com.cjs.example.account.service.IAccountService; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import org.springframework.stereotype.Service; @DS("account") @Service public class AccountServiceImpl extends ServiceImpl<AccountMapper, Account> implements IAccountService { }