<dependency>
  <groupId>com.atomikos</groupId>
  <artifactId>atomikos-tomcat-embedded</artifactId>
  <version>4.0.6</version>
</dependency>

spring:
  jta:
    atomikos:
      datasource:
        xa-data-source-class-name: com.mysql.cj.jdbc.MysqlXADataSource
        unique-resource-name: userDataSource
        xa-properties:
          user: root
          password: root
          URL: jdbc:mysql://localhost:3306/user_db?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
      test-on-borrow: true
      pool-size: 5

@Configuration
@EnableTransactionManagement
public class XaTransactionConfig {
  @Bean(initMethod = "init", destroyMethod = "close")
  public UserTransactionManager userTransactionManager() {
    UserTransactionManager userTransactionManager = new UserTransactionManager();
    userTransactionManager.setForceShutdown(false);
    return userTransactionManager;
  }
  @Bean
  public UserTransaction userTransaction() throws Throwable {
    UserTransactionImp userTransaction = new UserTransactionImp();
    userTransaction.setTransactionTimeout(10000);
    return userTransaction;
  }
  @Bean
  public PlatformTransactionManager transactionManager(UserTransactionManager userTransactionManager,
                                                       UserTransaction userTransaction,
                                                       @Qualifier("userDataSource") DataSource userDataSource) {
    return new JtaTransactionManager(userTransaction, userTransactionManager);
  }
  @Bean(name = "userDataSource")
  public DataSource userDataSource() {
    MysqlXADataSource mysqlXADataSource = new MysqlXADataSource();
    mysqlXADataSource.setURL("jdbc:mysql://localhost:3306/user_db?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC");
    mysqlXADataSource.setUser("root");
    mysqlXADataSource.setPassword("root");
    AtomikosDataSourceBean dataSourceBean = new AtomikosDataSourceBean();
    dataSourceBean.setUniqueResourceName("userDataSource");
    dataSourceBean.setXaDataSource(mysqlXADataSource);
    dataSourceBean.setMinPoolSize(5);
    dataSourceBean.setMaxPoolSize(20);
    dataSourceBean.setTestQuery("SELECT 1");
    return dataSourceBean;
  }
  @Bean(name = "orderDataSource")
  public DataSource orderDataSource() {
    MysqlXADataSource mysqlXADataSource = new MysqlXADataSource();
    mysqlXADataSource.setURL("jdbc:mysql://localhost:3306/order_db?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC");
    mysqlXADataSource.setUser("root");
    mysqlXADataSource.setPassword("root");
    AtomikosDataSourceBean dataSourceBean = new AtomikosDataSourceBean();
    dataSourceBean.setUniqueResourceName("orderDataSource");
    dataSourceBean.setXaDataSource(mysqlXADataSource);
    dataSourceBean.setMinPoolSize(5);
    dataSourceBean.setMaxPoolSize(20);
    dataSourceBean.setTestQuery("SELECT 1");
    return dataSourceBean;
  }
}

@Service
public class UserService {
  @Autowired
  private UserDao userDao;
  @Autowired
  private OrderDao orderDao;
  @Transactional(rollbackFor = Exception.class, propagation = Propagation.REQUIRED)
  public void createUserAndOrder(User user, Order order) throws Exception {
    userDao.createUser(user);
    orderDao.createOrder(order);
    if (order.getAmount() > user.getBalance()) {
      throw new Exception("Insufficient balance");
    }
    userDao.updateUserBalance(user.getId(), user.getBalance() - order.getAmount());
    orderDao.updateOrderStatus(order.getId(), "PAID");
  }
}