Spring Boot、具有多个数据源的 Spring Data JPA

Spring Boot与多数据源的Spring Data JPA

spring.datasource.url=jdbc:mysql://localhost:3306/main_database
spring.datasource.username=root
spring.datasource.password=123456
datasource.secondary.url=jdbc:mysql://localhost:3306/secondary_database
datasource.secondary.username=root
datasource.secondary.password=123456

java
@Configuration
public class DataSourceConfig {
    @Primary
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean
    @ConfigurationProperties(prefix = "datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }
}

java
@Configuration
@EnableJpaRepositories(
        basePackages = "com.example.repository.main",
        entityManagerFactoryRef = "mainEntityManagerFactory",
        transactionManagerRef = "mainTransactionManager"
)
public class MainJpaConfig {
    
    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;
    @Primary
    @Bean
    public LocalContainerEntityManagerFactoryBean mainEntityManagerFactory(EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(primaryDataSource)
                .packages("com.example.entity.main")
                .persistenceUnit("main")
                .build();
    }
    @Primary
    @Bean
    public PlatformTransactionManager mainTransactionManager(@Qualifier("mainEntityManagerFactory") EntityManagerFactory entityManagerFactory){
        return new JpaTransactionManager(entityManagerFactory);
    }
}

java
@Repository
public interface UserRepository extends JpaRepository {
    @Query(value = "SELECT * FROM users", nativeQuery = true)
    List getAllUsers();
}
@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;
    @Autowired
    @Qualifier("secondaryDataSource")
    private DataSource secondaryDataSource;
    public List getAllUsers() {
        // 使用主数据源进行查询
        return userRepository.findAll();
    }
    public List getAllUsersFromSecondaryDataSource() {
        // 切换到副本数据源进行查询
        JdbcTemplate jdbcTemplate = new JdbcTemplate(secondaryDataSource);
        return jdbcTemplate.query("SELECT * FROM users", (resultSet, rowNum) ->
                new User(resultSet.getLong("id"), resultSet.getString("name")));
    }
}