如何解决疯狂的 JPA 需求？答案

【问题标题】：How to solve Crazy JPA Requirements?如何解决疯狂的 JPA 需求？
【发布时间】：2016-04-27 08:25:22
【问题描述】：

在我的项目中，我使用 JPA 1.0 和 Hibernate 3.2.x 和 Tomcat 进行部署。

在我的项目中，我使用以下查询作为命名查询执行，

SELECT smSSTJob.smJob.jobId, smSSTJob.smJob.jobTypeId, smSSTJob.omObject.objectId, 
smSSTJob.omObject.objectName FROM SMSSTJob smSSTJob 
WHERE smSSTJob.smJob.jobTypeId IN (:jobTypeIdList) 
AND smSSTJob.jobStatusId IN (:jobStatusList) 
AND smSSTJob.omObject.objectId NOT IN (SELECT sm.omObject.objectId FROM SMSSTJob sm 
WHERE sm.jobStatusId IN (:unProcessedJobStatusList) 
AND sm.responseReceivedDate &gt; :responseReceivedDate)
AND smSSTJob.priority = :priority 
AND smSSTJob.jobRetries &lt; :maximumJobRetries ORDER BY smSSTJob.smJob.jobId

当我部署我的项目时，上述查询休眠引发了以下异常，

Caused by: java.lang.NullPointerException
at org.hibernate.hql.ast.tree.FromClause.findIntendedAliasedFromElementBasedOnCrazyJPARequirements(FromClause.java:120)
at org.hibernate.hql.ast.tree.FromClause.getFromElement(FromClause.java:107)
at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:81)
at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:70)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:255)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3056)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:2945)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:688)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:544)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.collectionFunctionOrSubselect(HqlSqlBaseWalker.java:4253)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.inRhs(HqlSqlBaseWalker.java:4161)

如何解决此异常？任何人都请在这种情况下帮助我。提前致谢。

【问题讨论】：

您是否检查了smSSTJob.smJob.jobTypeId 中的smJob 和smSSTJob.omObject.objectId 中的omObject 不是null？
smSSTJob 中的 smJob 和 omObject 都是 foreign key and not null 列。
Hibernate 3.2.6 或更低版本？
休眠版本是3.2.5ga
"Its still broken in the latest 3.2.5 GA download." 见here

标签： java hibernate jpa orm

【解决方案1】：

Hibernate中有一个bug，3.2.6及以后解决，尝试更新Hibernate版本

【讨论】：

【解决方案2】：

可能是缺少一个“）”吗？关闭您的子查询。

不在（从 SMSSTJob sm 中选择 sm.omObject.objectId WHERE sm.jobStatusId IN (:unProcessedJobStatusList)

【讨论】：

没有错……不在（从 SMSSTJob sm WHERE sm.jobStatusId IN (:unProcessedJobStatusList) AND sm.responseReceivedDate > :responseReceivedDate) 中选择 sm.omObject.objectId）