在DAO类使用HQl语句,然而getSession().createQuery(queryString)中getSession()返回空值,请问怎么解决?
这个异常怎么处理啊~~~
java.lang.NullPointerException
share.dao.TbUserbasicinfoDAO.findByUserName(TbUserbasicinfoDAO.java:259)
share.struts.action.LoginAction.execute(LoginAction.java:56)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
share.struts.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:37)
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在findByUserName这个方法
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public List findByProperty(String propertyName, Object value) {
<p> log.debug("finding TbAdministration instance with property: " </p>
<p> + propertyName + ", value: " + value); </p>
<p> try { String queryString = "from TbAdministration as model where model." </p>
<p> + propertyName + "= ?"; </p>
<p> Query queryObject = getSession().createQuery(queryString); </p>
<p> queryObject.setParameter(0, value); </p>
<p> return queryObject.list(); </p>
<p> } catch (RuntimeException re) { </p>
<p> log.error("find by property name failed", re); </p>
<p> throw re; </p>
<p> } </p>
<p> } </p>
<p> 里面getSession()返回了一个空的session,结果就抛了空值异常~~为什么会是空值啊~~</p>