如何使用spring通过null查询实体属性？

Question

我正在使用弹簧CrudRepository 来查询数据库实体。以下应该有效，但无效。

public interface MyEntityRepository<MyEntity> extends CrudRepository<MyEntity, Long> {}

@Entity
public class MyEntity() {
    private Long id;
    private Date reservation;
}

findByReservationIsNull(new PageRequest(0, 2, new Sort(Direction.DESC, "reservation"))));

我只是得到以下异常结果。为什么？我可能监督了什么？

java.util.NoSuchElementException
at java.util.ArrayList$Itr.next(ArrayList.java:854) ~[?:1.8.0_31]
at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1042) ~[?:1.8.0_31]
at org.springframework.data.jpa.repository.query.CriteriaQueryParameterBinder.bind(CriteriaQueryParameterBinder.java:63) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.ParameterBinder.bind(ParameterBinder.java:111) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.ParameterBinder.bindAndPrepare(ParameterBinder.java:172) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.ParameterBinder.bindAndPrepare(ParameterBinder.java:163) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.invokeBinding(PartTreeJpaQuery.java:207) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.createQuery(PartTreeJpaQuery.java:134) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.doCreateQuery(PartTreeJpaQuery.java:74) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.createQuery(AbstractJpaQuery.java:164) ~[spring-data-jpa-1.7.2.RELEASE.jar:?]
at org.springframework.data.jpa.repository.query.JpaQueryExecution$CollectionExecution.doExecute(JpaQueryExecution.java:110) ~[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$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodIntercceptor.invoke(CrudMethodMetadataPostProcessor.java:122) ~[spring-data-jpa-1.7.2.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.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-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.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) ~[spring-aop-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at com.sun.proxy.$Proxy112.findByReservationIsNull(Unknown Source) ~[?:?]

Answer 1

您需要使用：PagingAndSortingRepository 才能使用分页和排序。

看到这个类似的answer

顺便说一句，抛出此异常是因为 CrudRepository 中的 findByReservationIsNull 不期望任何参数，因此它找不到匹配的方法。