org.hibernate.exception.GenericJDBCException: could not inspect JDBC autocommit

org.hibernate.exception.GenericJDBCException: could not inspect JDBC autocommit mode
org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:82)
org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:70)
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
org.hibernate.jdbc.JDBCContext.afterNontransactionalQuery(JDBCContext.java:338)
org.hibernate.impl.SessionImpl.afterOperation(SessionImpl.java:398)
org.hibernate.impl.SessionImpl.list(SessionImpl.java:852)
org.hibernate.impl.QueryImpl.list(QueryImpl.java:74)
com.dfnm.hibernate.mapping.ReferDAO.findAll(ReferDAO.java:240)
com.dfnm.struts.action.ReferSelAction.execute(ReferSelAction.java:65)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

------解决方法--------------------------------------------------------
看样子应该是事务处理出现了问题...仔细检查下代码...
------解决方法--------------------------------------------------------
事务处理有问题。不能把事务定义为类的成员变量。
 

Java code

private Session s; public void referup(int id,int uid){  if(s==null||!s.isOpen())  {  s=(Session) this.getSession();  }  Transaction tr=s.beginTransaction();   try {  Refer refer=(Refer)s.load(Refer.class, id);  Users user=(Users)s.load(Users.class, uid);  refer.setUsersByReferAnswerid(user);  refer.setReferState(2);  s.update(refer);  tr.commit();  } catch (HibernateException e) {  // TODO Auto-generated catch block  e.printStackTrace();  tr.rollback();  }  s.close(); }