entitymanagerfactory 多数据源

@Configuration
public class DataSourceConfig {

    @Bean
    @Primary
    @ConfigurationProperties("spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties("spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }
}

@Configuration
@EnableJpaRepositories(
    basePackages = "com.example.primary.repositories",
    entityManagerFactoryRef = "primaryEntityManagerFactory",
    transactionManagerRef = "primaryTransactionManager"
)
public class PrimaryDataSourceConfig {

    @Primary
    @Bean
    public LocalContainerEntityManagerFactoryBean primaryEntityManagerFactory(
            EntityManagerFactoryBuilder builder, @Qualifier("primaryDataSource") DataSource dataSource) {
        return builder
                .dataSource(dataSource)
                .packages("com.example.primary.entities")
                .persistenceUnit("primary")
                .build();
    }

    @Primary
    @Bean
    public PlatformTransactionManager primaryTransactionManager(
            @Qualifier("primaryEntityManagerFactory") EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }
}

@Configuration
@EnableJpaRepositories(
    basePackages = "com.example.secondary.repositories",
    entityManagerFactoryRef = "secondaryEntityManagerFactory",
    transactionManagerRef = "secondaryTransactionManager"
)
public class SecondaryDataSourceConfig {

    @Bean
    public LocalContainerEntityManagerFactoryBean secondaryEntityManagerFactory(
            EntityManagerFactoryBuilder builder, @Qualifier("secondaryDataSource") DataSource dataSource) {
        return builder
                .dataSource(dataSource)
                .packages("com.example.secondary.entities")
                .persistenceUnit("secondary")
                .build();
    }

    @Bean
    public PlatformTransactionManager secondaryTransactionManager(
            @Qualifier("secondaryEntityManagerFactory") EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }
}

@SpringBootApplication
public class MultiDataSourceApplication {

    public static void main(String[] args) {
        SpringApplication.run(MultiDataSourceApplication.class, args);
    }
}

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    // getters and setters
}

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
}

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    @Transactional("primaryTransactionManager")
    public User saveUser(User user) {
        return userRepository.save(user);
    }
}