我得到这个例外：

Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space
    at java.util.Arrays.copyOf(Arrays.java:2882)
    at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:100)
    at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:390)
    at java.lang.StringBuilder.append(StringBuilder.java:119)
    at java.util.AbstractMap.toString(AbstractMap.java:493)
    at org.hibernate.pretty.Printer.toString(Printer.java:59)
    at org.hibernate.pretty.Printer.toString(Printer.java:90)
    at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:97)
    at org.hibernate.event.def.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:35)
    at org.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:969)
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1114)
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)

在此代码：

Query query = null;
        Transaction tx= session.beginTransaction();
        if (allRadio.isSelected()) {
            query = session.createQuery("select d from Document as d, d.msg as m, m.senderreceivers as s where m.isDraft=0 and d.isMain=1 and s.organization.shortName like '" + search + "' and s.role=0");
        } else if (periodRadio.isSelected()) {
            query = session.createQuery("select d from Document as d, d.msg as m, m.senderreceivers as s where m.isDraft=0 and d.isMain=1 and s.organization.shortName like '" + search + "' and s.role=0 and m.receivingDate between :start and :end");
            query.setParameter("start", start);
            query.setParameter("end", end);
        }
        final List<Document> documents = query.list();


        query = session.createQuery("select o from Organization as o");
        List<Organization> organizations = query.list(); <---AT THIS LINE
        tx.commit();

我连续2次查询。如果我评论其中之一，其他工作正常。

如果我删除交易，那么事物异常便消失了。这是怎么回事？这是内存泄漏之类的吗？提前致谢。