Name		Name	Last commit message	Last commit date
.mvn/wrapper		.mvn/wrapper
src		src
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
mvnw		mvnw
mvnw.cmd		mvnw.cmd
pom.xml		pom.xml

Repository files navigation

简单实现 Spring Boot 多数据源

Simple Spring Boot Multi-DataSource

Usage

// In Mapper
@UsingDataSource(DataSourceType.SLAVE)
User selectByPrimaryKey(Integer id);

// Or In Service
@UsingDataSource(DataSourceType.MASTER)
public User getUserFromSlave1(Integer id) {
  return userDao.selectByPrimaryKey(id);
}

@UsingDataSource(DataSourceType.SLAVE)
public User getUserFromSlave(Integer id) {
  return userDao.selectByPrimaryKey(id);
}

How to

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_master
      username: root
      password: rootroot
    slave:
      jdbc-url: jdbc:mysql://localhost:3306/multi_datasource_slave
      username: root
      password: rootroot
    slave2:
      jdbc-url: jdbc:mysql://localhost:3306/multi_datasource_slave_2
      username: root
      password: rootroot

数据源配置

@Configuration
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
public class DataSourceConfig {

    /**
     * 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")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 从库 1 数据源配置
     */
    @Bean("SLAVE")
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource slaveDataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 从库 2 数据源配置
     */
    @Bean("SLAVE_2")
    @ConfigurationProperties(prefix = "spring.datasource.slave2")
    public DataSource slave2DataSource() {
        return DataSourceBuilder.create().build();
    }
}

定义数据源类型枚举

public enum DataSourceType {
    /**
     * 主库
     */
    MASTER,

    /**
     * 从库 1
     */
    SLAVE,

    /**
     * 从库 2
     */
    SLAVE_2,
    ;

    /**
     * 默认的数据源类型
     */
    public static final DataSourceType DEFAULT = MASTER;
}

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

@Primary
@Component
public class DynamicRoutingDataSource extends AbstractRoutingDataSource {

    private final Map<String, DataSource> dataSourceMap;

    public static final ThreadLocal<DataSourceType> TYPE_HOLDER = ThreadLocal.withInitial(() -> DataSourceType.DEFAULT);

    public DynamicRoutingDataSource(Map<String, DataSource> dataSourceMap) {
        this.dataSourceMap = dataSourceMap;
    }

    @Override
    protected Object determineCurrentLookupKey() {
        return TYPE_HOLDER.get();
    }

    @PostConstruct
    private void postConstruct() {
        // 设置默认数据源
        String defaultDataSourceName = DataSourceType.DEFAULT.name();
        DataSource defaultDataSource = dataSourceMap.get(defaultDataSourceName);
        setDefaultTargetDataSource(defaultDataSource);

        // 设置数据源及其类型映射
        Map<Object, Object> targetDataSources = new HashMap<>();
        dataSourceMap.forEach((name, ds) -> targetDataSources.put(DataSourceType.valueOf(name), ds));
        setTargetDataSources(targetDataSources);
    }
}

指定使用数据源类型注解

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface UsingDataSource {
    DataSourceType value() default DataSourceType.MASTER;
}

数据源切换拦截切面

@Slf4j
@Aspect
@Component
public class UsingDataSourceAspect {

    @Around("@annotation(usingDataSource)")
    public Object around(ProceedingJoinPoint joinPoint, UsingDataSource usingDataSource) throws Throwable {
        DataSourceType type = 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);
        Object res;
        try {
            res = joinPoint.proceed();
        } finally {
            // 恢复数据源
            DynamicRoutingDataSource.TYPE_HOLDER.remove();
        }
        return res;
    }
}

使用

@Service
public class UserService {

    private final UserDao userDao;

    public UserService(UserDao userDao) {
        this.userDao = userDao;
    }

    public User getUser(Integer id) {
        return userDao.selectByPrimaryKey(id);
    }

    @UsingDataSource
    public User getUserFromDefault(Integer id) {
        return userDao.selectByPrimaryKey(id);
    }

    @UsingDataSource(DataSourceType.SLAVE)
    public User getUserFromSlave1(Integer id) {
        return userDao.selectByPrimaryKey(id);
    }

    @UsingDataSource(DataSourceType.SLAVE_2)
    public User getUserFromSlave2(Integer id) {
        return userDao.selectByPrimaryKey(id);
    }
}

Have fun! 😁

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

@SpringBootTest
class MultiDatasourceApplicationTests {

  @Autowired
  private UserService userService;

  @Test
  void contextLoads() {
  }

  @Test
  public void getUser() {
    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 = 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 source type 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 source type 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 source type 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 source type 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 source type 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 source type 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)