hibernate问题：session已经关闭了，居然还能更新数据库，奇怪！

/**
* 根据知识Id号查找知识的详细信息 (用户浏览信息)
*
* @param knowledgeId
* @return
*/
public List findMyKnowledgeByKnowledgeId(int knowledgeId) {
Session session = HibernateUtil.currentSession();
List<KmsKnowledge> li = new ArrayList<KmsKnowledge>();
// knowledgeResult=2表示已通过的知识

String hql = "from KmsKnowledge as k where k.knowledgeId='"
+ knowledgeId + "' ";

List list = session.createQuery(hql).list();
KmsKnowledge k = new KmsKnowledge();
KmsKnowledge kn = new KmsKnowledge();
for (java.util.Iterator iter = list.iterator(); iter.hasNext();) {
kn = (KmsKnowledge) iter.next();

}

HibernateUtil.closeSession();

if (session.isOpen()) {
System.out.println("session马上就要关闭了");
session.close();
}
/** *******文件解密*********** */
DesEncrypt des = new DesEncrypt();
des.getKey("sneb");

String knowledgeContent = des.getDesString(kn.getKnowledgeContent());
String knowledgeSub = des.getDesString(kn.getKnowledgeSub());
String knowledgeBg = des.getDesString(kn.getKnowledgeBg());

k.setKnowledgeContent(knowledgeContent);
k.setKnowledgeSub(knowledgeSub);
k.setKnowledgeBg(knowledgeBg);

li.add(k);
return li;
}