它仅通过以下堆栈跟踪复制了一次
Caused by: java.lang.NullPointerException at org.hibernate.event.def.AbstractFlushingEventListener.prepareEntityFlushes(AbstractFlushingEventListener.java:119) at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:65) at org.hibernate.event.def.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:35) at org.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:970) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1115) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
有人知道什么是原因吗?
Hibernate 版本是 3.2.7.GA
我确信原因不在当前查询中,因为每个列表都会执行。为什么flush for current session会掉下来?可以通过某种方式预防吗?
最佳答案
private void prepareEntityFlushes(EventSource session) throws HibernateException {
log.debug("processing flush-time cascades");
final Map.Entry[] list = IdentityMap.concurrentEntries( session.getPersistenceContext().getEntityEntries() );
//safe from concurrent modification because of how entryList() is implemented on IdentityMap
final int size = list.length;
final Object anything = getAnything();
for ( int i=0; i<size; i++ ) {
Map.Entry me = list[i];
EntityEntry entry = (EntityEntry) me.getValue(); //nullpointer here!
Status status = entry.getStatus();
if ( status == Status.MANAGED || status == Status.SAVING ) {
cascadeOnFlush( session, entry.getPersister(), me.getKey(), anything );
}
}
}
IdentityMap.concurrentEntries
返回一个 Map.Entry 数组,其中包含所提供 map 的条目。看起来从 session.getPersistenceContext().getEntityEntries()
的映射中返回了一个空元素,尝试获取源代码(应该可以通过大多数 IDE 获取)并调试该方法。另外,检查你的实体定义,那里可能有问题..
关于java - Query.list() 中的 Hibernate NullPointerException,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18073842/