简单实现 Spring Boot 多数据源

Simple Spring Boot Multi-DataSource

Usage

// In Mapper@UsingDataSource(DataSourceType.SLAVE)
UserselectByPrimaryKey(Integerid);
// Or In Service@UsingDataSource(DataSourceType.MASTER)
publicUsergetUserFromSlave1(Integerid) {
returnuserDao.selectByPrimaryKey(id);
}
@UsingDataSource(DataSourceType.SLAVE)
publicUsergetUserFromSlave(Integerid) {
returnuserDao.selectByPrimaryKey(id);
}

How to

1. 在 application.yml 中添加数据源对应的配置信息

   spring:
   datasource:
   master:
   jdbc-url: jdbc:mysql://localhost:3306/multi_datasource_masterusername: rootpassword: rootrootslave:
   jdbc-url: jdbc:mysql://localhost:3306/multi_datasource_slaveusername: rootpassword: rootrootslave2:
   jdbc-url: jdbc:mysql://localhost:3306/multi_datasource_slave_2username: rootpassword: rootroot

2. 数据源配置

   @Configuration@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
   publicclassDataSourceConfig {
   /** * 主库数据源配置，Bean name 与 {@link DataSourceType} 中对应枚举类型名相同，以达到校验作用 */@Bean("MASTER")
   @ConfigurationProperties(prefix = "spring.datasource.master")
   publicDataSourcemasterDataSource() {
   returnDataSourceBuilder.create().build();
   }
   /** * 从库 1 数据源配置 */@Bean("SLAVE")
   @ConfigurationProperties(prefix = "spring.datasource.slave")
   publicDataSourceslaveDataSource() {
   returnDataSourceBuilder.create().build();
   }
   /** * 从库 2 数据源配置 */@Bean("SLAVE_2")
   @ConfigurationProperties(prefix = "spring.datasource.slave2")
   publicDataSourceslave2DataSource() {
   returnDataSourceBuilder.create().build();
   }
   }

3. 定义数据源类型枚举

   publicenumDataSourceType {
   /** * 主库 */MASTER,
   /** * 从库 1 */SLAVE,
   /** * 从库 2 */SLAVE_2,
   ;
   /** * 默认的数据源类型 */publicstaticfinalDataSourceTypeDEFAULT = MASTER;
   }

4. 动态数据源配置，配合 UsingDataSource、UsingDataSourceAspect 实现数据源切换

   @Primary@ComponentpublicclassDynamicRoutingDataSourceextendsAbstractRoutingDataSource {
   privatefinalMap<String, DataSource> dataSourceMap;
   publicstaticfinalThreadLocal<DataSourceType> TYPE_HOLDER = ThreadLocal.withInitial(() -> DataSourceType.DEFAULT);
   publicDynamicRoutingDataSource(Map<String, DataSource> dataSourceMap) {
   this.dataSourceMap = dataSourceMap;
   }
   @OverrideprotectedObjectdetermineCurrentLookupKey() {
   returnTYPE_HOLDER.get();
   }
   @PostConstructprivatevoidpostConstruct() {
   // 设置默认数据源StringdefaultDataSourceName = DataSourceType.DEFAULT.name();
   DataSourcedefaultDataSource = dataSourceMap.get(defaultDataSourceName);
   setDefaultTargetDataSource(defaultDataSource);
   // 设置数据源及其类型映射Map<Object, Object> targetDataSources = newHashMap<>();
   dataSourceMap.forEach((name, ds) -> targetDataSources.put(DataSourceType.valueOf(name), ds));
   setTargetDataSources(targetDataSources);
   }
   }

5. 指定使用数据源类型注解

   @Target(ElementType.METHOD)
   @Retention(RetentionPolicy.RUNTIME)
   public @interface UsingDataSource {
   DataSourceTypevalue() defaultDataSourceType.MASTER;
   }

6. 数据源切换拦截切面

   @Slf4j@Aspect@ComponentpublicclassUsingDataSourceAspect {
   @Around("@annotation(usingDataSource)")
   publicObjectaround(ProceedingJoinPointjoinPoint, UsingDataSourceusingDataSource) throwsThrowable {
   DataSourceTypetype = usingDataSource.value();
   log.debug("data source type is {}", type);
   // 保存要切换到的数据源类型DynamicRoutingDataSource.TYPE_HOLDER.set(type);
   Objectres;
   try {
   res = joinPoint.proceed();
   } finally {
   // 恢复数据源DynamicRoutingDataSource.TYPE_HOLDER.remove();
   }
   returnres;
   }
   }

7. 使用

   @ServicepublicclassUserService {
   privatefinalUserDaouserDao;
   publicUserService(UserDaouserDao) {
   this.userDao = userDao;
   }
   publicUsergetUser(Integerid) {
   returnuserDao.selectByPrimaryKey(id);
   }
   @UsingDataSourcepublicUsergetUserFromDefault(Integerid) {
   returnuserDao.selectByPrimaryKey(id);
   }
   @UsingDataSource(DataSourceType.SLAVE)
   publicUsergetUserFromSlave1(Integerid) {
   returnuserDao.selectByPrimaryKey(id);
   }
   @UsingDataSource(DataSourceType.SLAVE_2)
   publicUsergetUserFromSlave2(Integerid) {
   returnuserDao.selectByPrimaryKey(id);
   }
   }

8. Have fun! 😁

   你可以使用 MultiDatasourceApplicationTests.getUser() 进行测试

   @SpringBootTestclassMultiDatasourceApplicationTests {
   @AutowiredprivateUserServiceuserService;
   @TestvoidcontextLoads() {
   }
   @TestpublicvoidgetUser() {
   Useruser;
   user = userService.getUser(1);
   System.out.println("user = " + user);
   user = userService.getUserFromDefault(1);
   System.out.println("user = " + user);
   user = userService.getUserFromSlave1(1);
   System.out.println("user = " + user);
   user = userService.getUserFromSlave2(1);
   System.out.println("user = " + user);
   user = userService.getUser(1);
   System.out.println("user = " + user);
   user = userService.getUserFromDefault(1);
   System.out.println("user = " + user);
   user = userService.getUserFromSlave1(1);
   System.out.println("user = " + user);
   user = userService.getUserFromSlave2(1);
   System.out.println("user = " + user);
   }
   }

   user = User(id=1, username=master_username, password=master_password, sex=1, create_time=Fri Feb 19 11:59:35 CST 2021, update_time=Fri Feb 19 11:59:35 CST 2021, deleted=0)
   2021-02-20 10:02:12.169 INFO 13053 --- [ main] c.e.m.config.UsingDataSourceAspect : data sourcetype is MASTER
   user = User(id=1, username=master_username, password=master_password, sex=1, create_time=Fri Feb 19 11:59:35 CST 2021, update_time=Fri Feb 19 11:59:35 CST 2021, deleted=0)
   2021-02-20 10:02:12.171 INFO 13053 --- [ main] c.e.m.config.UsingDataSourceAspect : data sourcetype is SLAVE
   user = User(id=1, username=slave_username, password=slave_password, sex=1, create_time=Fri Feb 19 17:05:37 CST 2021, update_time=Fri Feb 19 17:05:37 CST 2021, deleted=0)
   2021-02-20 10:02:12.186 INFO 13053 --- [ main] c.e.m.config.UsingDataSourceAspect : data sourcetype is SLAVE_2
   user = User(id=1, username=slave_2_username, password=slave_2_password, sex=1, create_time=Sat Feb 20 10:00:59 CST 2021, update_time=Sat Feb 20 10:00:59 CST 2021, deleted=0)
   user = User(id=1, username=master_username, password=master_password, sex=1, create_time=Fri Feb 19 11:59:35 CST 2021, update_time=Fri Feb 19 11:59:35 CST 2021, deleted=0)
   2021-02-20 10:02:12.203 INFO 13053 --- [ main] c.e.m.config.UsingDataSourceAspect : data sourcetype is MASTER
   user = User(id=1, username=master_username, password=master_password, sex=1, create_time=Fri Feb 19 11:59:35 CST 2021, update_time=Fri Feb 19 11:59:35 CST 2021, deleted=0)
   2021-02-20 10:02:12.206 INFO 13053 --- [ main] c.e.m.config.UsingDataSourceAspect : data sourcetype is SLAVE
   user = User(id=1, username=slave_username, password=slave_password, sex=1, create_time=Fri Feb 19 17:05:37 CST 2021, update_time=Fri Feb 19 17:05:37 CST 2021, deleted=0)
   2021-02-20 10:02:12.208 INFO 13053 --- [ main] c.e.m.config.UsingDataSourceAspect : data sourcetype is SLAVE_2
   user = User(id=1, username=slave_2_username, password=slave_2_password, sex=1, create_time=Sat Feb 20 10:00:59 CST 2021, update_time=Sat Feb 20 10:00:59 CST 2021, deleted=0)