Spring 数据存储库 StackOverflow

Question

使用 Spring Data Repositories 时发现了一些奇怪的行为。

我写了这些类和接口：

@Transactional(readOnly = true)
public interface UserRepository extends Repository<User, Integer> {

    @Transactional
    @Modifying
    @Query("DELETE FROM User u WHERE u.id=:id")
    int delete(@Param("id") int id);

    @Transactional
    User save(User user);

    User findOne(Integer id);

    List<User> findAll();
}


public interface AbstractRepository<T> {

    T save(T user);

    // false if not found
    boolean delete(int id);

    // null if not found
    T get(int id);

    List<T> getAll();
    }



@Repository
public class UserRepositoryImpl implements AbstractRepository<User> {

    @Autowired
    private JpaUserRepository repository;

    @Override
    public User save(User user) {
        return repository.save(user);
    }

    @Override
    public boolean delete(int id) {
        return repository.delete(id) != 0;
    }

    @Override
    public User get(int id) {
        return repository.findOne(id);
    }

    @Override
    public List<User> getAll() {
        return repository.findAll();
    }
}

当我尝试测试 UserRepositoryImpl 时，抛出 java.lang.StackOverflowError

Caused by: java.lang.StackOverflowError
    at org.springframework.data.repository.util.ClassUtils.unwrapReflectionException(ClassUtils.java:166)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:505)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:478)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:460)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:115)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy55.save(Unknown Source)
    at ru.emitrohin.votingsystem.repository.UserRepositoryImpl.save(RestaurantRepositoryImpl.java:24)
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
    at  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

我看到 save() 方法存在一些问题。在 delete() 方法上也抛出了 stackoverflow。

我已经找到了解决方案。当我将扩展 Repository 接口的接口名称更改为（例如）JpaUserRepository 时，我的问题就消失了。

所以，问题是“发生了什么”。为什么实现spring数据存储库的接口名称与模式Classname Repository匹配时会抛出stackoverflow ？

我的 pom.xml

Caused by: java.lang.StackOverflowError
    at org.springframework.data.repository.util.ClassUtils.unwrapReflectionException(ClassUtils.java:166)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:505)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:478)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:460)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:115)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy55.save(Unknown Source)
    at ru.emitrohin.votingsystem.repository.UserRepositoryImpl.save(RestaurantRepositoryImpl.java:24)
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
    at  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

Answer 1

好吧，问题不是因为Classname RepositoryImpl 命名而是因为RepositoryClassname Impl 命名。您这样做是在告诉 Spring 您正在为RepositoryClassname接口上的某些方法提供自定义行为。也就是说，Spring 正在为您实现JpaRepository 中的所有标准 CRUD 方法。您的实现允许您注入存储库 bean，但它旨在用作实现的一部分，而不仅仅是用于委托. 当您在 Impl 类中实现 save() 时，您实际上是在为接口 save() 提供自定义实现因此，当您在“自定义”实现中调用接口 save() 时，您正在强制一个以 stackoverflow 异常结束的无限循环。

如果您不打算提供自定义行为，请不要在 Impl 类中声明该方法。另一方面，如果您不想为某些接口方法提供自定义行为，而只是想创建一个单独的存储库，请不要将其命名为RepositoryInterfaceName Impl。如果您试图修改实现，请不要调用 interface.save() 方法。

PS：通常在持久层使用@Transactional 是一种不好的做法，我认为在服务层使用@Transactional 总是更好，因为它会处理您的业务逻辑。查看此帖子以获取更多信息。