带有 Java 8 流 NonUniqueResultException 的 Spring DATA JPA

Question

我定义了一个基于 PagingAndSortingRepository 的存储库来实现以下查询

@Query(" SELECT me FROM CustomerModelEntity me WHERE  me.planNum = :planNum AND me.customerModelStatusCode IN ('AVL','PHO')" +
        " AND me.modelCode IN (SELECT e.modelCode FROM ModelEntity e WHERE e.modelStatusCode IN ('AVL','PHO'))")
Stream<CustomerModelEntity> findByPlanNum(@Param("planNum") String planNum);

结果预计会有多个结果。但是，结果出来是一个例外，如下所示

Caused by: javax.persistence.NonUniqueResultException: result returns more than one elements
    at org.hibernate.jpa.internal.QueryImpl.getSingleResult(QueryImpl.java:505) [hibernate-entitymanager-4.3.7.Final.jar:4.3.7.Final]
    at org.springframework.data.jpa.repository.query.JpaQueryExecution$SingleEntityExecution.doExecute(JpaQueryExecution.java:202) [spring-data-jpa-1.7.2.RELEASE.jar:]
    at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:74) [spring-data-jpa-1.7.2.RELEASE.jar:]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:97) [spring-data-jpa-1.7.2.RELEASE.jar:]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:88) [spring-data-jpa-1.7.2.RELEASE.jar:]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:395) [spring-data-commons-1.9.2.RELEASE.jar:]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:373) [spring-data-commons-1.9.2.RELEASE.jar:]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$DefaultMethodInvokingMethodInterceptor.invoke(RepositoryFactorySupport.java:486) [spring-data-commons-1.9.2.RELEASE.jar:]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) [spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) [spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) [spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) [spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
    ... 125 more

如果我有 List 而不是 Stream，则相同的 @Query 实现效果很好

@Query(" SELECT me FROM CustomerModelEntity me WHERE  me.planNum = :planNum AND me.customerModelStatusCode IN ('AVL','PHO')" +
        " AND me.modelCode IN (SELECT e.modelCode FROM ModelEntity e WHERE e.modelStatusCode IN ('AVL','PHO'))")
List<CustomerModelEntity> findByPlanNum(@Param("planNum") String planNum);

可以安全地假设 Spring Data JPA 中的 Java 8 支持不完整/我在这里做错了吗？

Answer 1

根据Spring数据JPA documentation：

目前并非所有 Spring Data 模块都支持 Stream 作为返回类型。

尝试更改PagingAndSortingRepository -> JpaRepository 看看是否有效。

更新：

我进一步调试，发现 Spring Data JPA 1.8.0 支持 Streaming，如果您使用其他版本，请升级到 1.8.0。我在 1.7.2 上遇到了同样的异常