java - 执行hibernate查询时出错

Question

执行获取 HQL 查询时出现异常。该查询大部分时间都有效，但有时会显示此异常

数据库为MySQL，使用的服务器为JBoss 5.1.0 GA

显示的错误是:

org.hibernate.exception.GenericJDBCException: could not execute query at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126) at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.loader.Loader.doList(Loader.java:2231) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125) at org.hibernate.loader.Loader.list(Loader.java:2120) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:361) at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102) at java.lang.Thread.run(Thread.java:745) Caused by: org.jboss.util.NestedSQLException: Error; - nested throwable: (java.lang.OutOfMemoryError: GC overhead limit exceeded) at org.jboss.resource.adapter.jdbc.WrappedConnection.checkException(WrappedConnection.java:873) at org.jboss.resource.adapter.jdbc.WrappedStatement.checkException(WrappedStatement.java:852) at org.jboss.resource.adapter.jdbc.WrappedResultSet.checkException(WrappedResultSet.java:1947) at org.jboss.resource.adapter.jdbc.WrappedResultSet.getString(WrappedResultSet.java:892) at org.hibernate.type.StringType.get(StringType.java:41) at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:184) at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:173) at org.hibernate.type.AbstractType.hydrate(AbstractType.java:105) at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:2124) at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1404) at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1332) at org.hibernate.loader.Loader.getRow(Loader.java:1230) at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:603) at org.hibernate.loader.Loader.doQuery(Loader.java:724) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259) at org.hibernate.loader.Loader.doList(Loader.java:2228) ... 11 more Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded

Answer 1

您的应用程序似乎内存不足。查询可能会返回非常大的数据集，因此分配给应用程序的内存不足以处理该数据集。 您可以，

• 增加分配给 Java 进程的内存，或者
• 按子集(分页)获取数据，以避免一次返回大型数据集。