Hql处理日期格式化问题

Date date=Calendar.getInstance().getTime();
Date date1=Calendar.getInstance().getTime();
String hql ="From Student s where 1=1 "
+" and s.time != null "
+" and s.time >:date "
+" and s.time <=:date1 ";
Query query=sessionFactory.createQuery(hql);
query.setTimestamp("date", date);//注意这里，用setTimestampe，不要用setDate
query.setTimestamp("date1", date1);
List<Student> list=query.list();

java.util.Date date=new java.util.Date();
String hql="select i from table i where to_char(i.date,'yyyy-MM-dd') =  to_char(?,yyyy-MM-dd)";
Query q=new Query(hql);
q.setDate(0,date);

java.util.Date date=new java.util.Date();
String hql="select i from table i where i.date=?";
Query q=new Query(hql);
q.setDate(0,date);