spring - 将 hibernate 命名策略设置为 Spring bean

Question

我有一个带有 Hibernate 的 spring-boot 应用程序。我想提供自定义 NamingStrategy 来为 hibernate 管理的每个表添加前缀。

我发现我可以使用属性:

spring.jpa.hibernate.naming_strategy=com.whatever.MyNamingStrategy

这很好用，除了我想拥有基于属性的动态前缀。我的目标是拥有类似的东西:

@Component
public class PrefixNamingStrategy extends DefaultNamingStrategy {

    private final String prefix;

    @Autowired
    public PrefixNamingStrategy(@Value("db.table.prefix") String prefix) {
        this.prefix = prefix;
    }

    @Override
    public String tableName(String tableName) {
        return prefix + super.tableName(tableName);
    }
}

显然这不适用于属性。

我尝试提供自定义 SessionFactory 并在那里提供 NamingStrategy 但没有成功 - 该 bean 是在 hibernate 初始化之后创建的，甚至似乎没有被使用:

@Autowired
@Bean(name = "sessionFactory")
public SessionFactory getSessionFactory(DataSource dataSource) {

    LocalSessionFactoryBuilder sessionBuilder = new LocalSessionFactoryBuilder(dataSource);

    sessionBuilder.setNamingStrategy(...); // !

    return sessionBuilder.buildSessionFactory();
}

有没有办法提供自定义 NamingStrategy 作为 bean？

干杯

Answer 1

虽然知道这不太理想，但我最终通过了 VendorAdapter:

1. 命名策略委托(delegate)者(注意 NamingStrategy 已被弃用):

   @Component
   public class PrefixNamingStrategyDelegator extends ImprovedNamingStrategyDelegator {
   
   @Autowired
   public PrefixNamingStrategyDelegator(final @Value("${application.environment}_") String prefix) {
       super(
               new HbmNamingStrategyDelegate() {
                   @Override
                   public String toPhysicalTableName(String tableName) {
                       return prefix + super.toPhysicalTableName(tableName);
                   }
               },
               new JpaNamingStrategyDelegate() {
                   @Override
                   public String toPhysicalTableName(String tableName) {
                       return prefix + super.toPhysicalTableName(tableName);
                   }
               }
       );
   }
   
   @Override
   public NamingStrategyDelegate getNamingStrategyDelegate(boolean isHbm) {
       return super.getNamingStrategyDelegate(isHbm);
   }
   }
   

2. JpaPersistenceProvider 将 NamingStrategyDelegator 潜入其中:

   @Component
   /**
    * See {@link org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider}
    *
    * We can't subclass that class but still need to sneak {@link org.hibernate.cfg.naming.NamingStrategyDelegator} into it.
    */
   public class SpringHibernateJpaPersistenceProviderWithNamingStrategy extends HibernatePersistenceProvider {
   
   private final NamingStrategyDelegator namingStrategy;
   
   @Autowired
   public SpringHibernateJpaPersistenceProviderWithNamingStrategy(NamingStrategyDelegator namingStrategy) {
       this.namingStrategy = namingStrategy;
   }
   
   @Override
   public EntityManagerFactory createContainerEntityManagerFactory(final PersistenceUnitInfo info, Map properties) {
       return new EntityManagerFactoryBuilderImpl(new PersistenceUnitInfoDescriptor(info), properties) {
           @Override
           public Configuration buildHibernateConfiguration(ServiceRegistry serviceRegistry) {
               Configuration configuration = super.buildHibernateConfiguration(serviceRegistry);
               if (info instanceof SmartPersistenceUnitInfo) {
                   for (String managedPackage : ((SmartPersistenceUnitInfo) info).getManagedPackages()) {
                       configuration.addPackage(managedPackage);
                   }
               }
   
               configuration.setNamingStrategyDelegator(namingStrategy);
   
               return configuration;
           }
       }.build();
   }
   }
   

3. 在我的@Configuration中:

   @Bean
   public AbstractJpaVendorAdapter customJPAVendorAdapter(HibernatePersistenceProvider jpaPersistenceProvider) {
       return new HibernateJpaVendorAdapter() {
           @Override
           public PersistenceProvider getPersistenceProvider() {
               return jpaPersistenceProvider;
           }
       };
   }
   

PersistenceProvider 本身是 SpringHibernateJpaPersistenceProvider 的原始副本(它的包是私有(private)的，不能被子类化)，添加了一行:

configuration.setNamingStrategyDelegator(namingStrategy);

有效。但是很丑……(你知道的)