Spring Jpa 将自定义功能添加到所有存储库，同时将其他自定义功能添加到单个存储库

Question

此处的 Spring 文档 http://docs.spring.io/spring-data/data-jpa/docs/current/reference/html/repositories.html#repositories.custom-implementations给出了将自定义功能添加到所有存储库或单个存储库的示例，而不是两者。

假设我想将一些自定义函数添加到所有存储库(使用自定义存储库工厂 Bean)和其他一些仅添加到单个存储库(文档说使用自定义接口(interface)和自定义 Impl)；我怎样才能做到这一点？

我在所有存储库中添加了“setCurrentTenansInSession”方法的一些示例代码；现在我想添加一个自定义方法，例如“newCustomMethod”，到单个存储库(即 MyJpaRepository，对于我的自定义存储库工厂)。我该怎么做呢？

自定义行为接口(interface):

@NoRepositoryBean
public interface MyJpaRepository<T, ID extends Serializable> extends JpaRepository<T, ID> { 
    public void setCurrentTenantInSession(Object object);       
}

自定义行为实现:

public class MultiTenantSimpleJpaRepository<T, ID extends Serializable> extends SimpleJpaRepository<T, ID> implements MyJpaRepository<T, ID> {
    public void setCurrentTenantInSession(Object object) {
        //custom impl
    }
}

自定义存储库工厂 bean:

public class MultiTenantJpaRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extends Serializable> extends JpaRepositoryFactoryBean<T, S, ID> {

    @Override
    protected RepositoryFactorySupport createRepositoryFactory(EntityManager entityManager) {
        return new MultiTenantJpaRepositoryFactory(entityManager);
    }
}

最后是自定义存储库工厂:

public class MultiTenantJpaRepositoryFactory extends JpaRepositoryFactory {
    public MultiTenantJpaRepositoryFactory(EntityManager entityManager) {
        super(entityManager);
    }

    @Override
    protected JpaRepository<?, ?> getTargetRepository(RepositoryMetadata metadata, EntityManager entityManager) {
        final JpaEntityInformation<?, Serializable> entityInformation = getEntityInformation(metadata.getDomainType());

        final SimpleJpaRepository<?, ?> repo = new MultiTenantSimpleJpaRepository(entityInformation, entityManager);

        repo.setLockMetadataProvider(LockModeRepositoryPostProcessor.INSTANCE.getLockMetadataProvider());
        return repo;
    }

    @Override
    protected Class<?> getRepositoryBaseClass(RepositoryMetadata metadata) {
        return MultiTenantSimpleJpaRepository.class;
    }
}

Answer 1

您只需要结合您提到的文档页面上的方法。让 Car成为您想要为其拥有自定义存储库的实体。
CommonCustomRepository定义添加到所有 repos 的方法:

@NoRepositoryBean
public interface CommonCustomRepository<T, ID extends Serializable> extends JpaRepository<T, ID> {
    String getCustomValue();
}

这个 repo 的实现:

public class CommonCustomRepositoryImpl<T, ID extends Serializable> extends SimpleJpaRepository<T, ID> implements CommonCustomRepository<T, ID> {

    public CommonCustomRepositoryImpl(Class<T> domainClass, EntityManager em) {
        super(domainClass, em);
    }

    public CommonCustomRepositoryImpl(JpaEntityInformation<T, ?> entityInformation,
            EntityManager entityManager) {
        super(entityInformation, entityManager);
    }

    @Override
    public String getCustomValue() {
        return "CustomValue";
    }

}

CarRepository 的自定义方法

@NoRepositoryBean
public interface CustomCarRepository {

    public String getCustomCarValue();
}

定制车相关方法的实现

public class CarRepositoryImpl implements CustomCarRepository {

    @PersistenceContext
    private EntityManager em;

    @Override
    public String getCustomCarValue() {
        return "CustomCarValue";
    }
}

CarRepository 的组合接口(interface)

public interface CarRepository extends CommonCustomRepository<Car, Long>, CustomCarRepository {
}

自定义仓库工厂，就像在文档中一样

public class CustomRepositoryFactoryBean<R extends JpaRepository<T, I>, T, I extends Serializable> extends
    JpaRepositoryFactoryBean<R, T, I> {

    @Override
    protected RepositoryFactorySupport createRepositoryFactory(EntityManager entityManager) {

        return new CustomRepositoryFactory(entityManager);
    }

    private static class CustomRepositoryFactory<T, I extends Serializable> extends JpaRepositoryFactory {

        private EntityManager entityManager;

        public CustomRepositoryFactory(EntityManager entityManager) {
            super(entityManager);

            this.entityManager = entityManager;
        }

        @Override
        protected Object getTargetRepository(RepositoryMetadata metadata) {

            return new CommonCustomRepositoryImpl<T, I>((Class<T>) metadata.getDomainType(), entityManager);
        }

        @Override
        protected Class<?> getRepositoryBaseClass(RepositoryMetadata metadata) {

            // The RepositoryMetadata can be safely ignored, it is used by the JpaRepositoryFactory
            // to check for QueryDslJpaRepository's which is out of scope.
            return CommonCustomRepositoryImpl.class;
        }
    }
}

最后一点配置，就像在文档中一样

<jpa:repositories base-package="com.example" factory-class="com.example.CustomRepositoryFactoryBean"/>