Criteria对象的获取：
Criteria criteria = session.createCriteria(Person.class); // Person为POJO类
criteria.add(Expression.eq("name","han")); // name为Person类的属性 相当于 name = 'han'
List list = criteria.list();
Expression.eq [=]
Expression.gt [>]
Expression.ge [>=]
Expression.lt [<]
Expression.ie [<=]
Expression.between("age",new Integer(13),new Integer(14)) [between.....and.......]
Expression.like("name","%han%") [like]
Set<Integer> conds = new TreeSet<Integer>();conds.add(new Integer(1));conds.add(new Integer(2));
cri.add(Expression.in("id", conds)); [IN] 相当于id IS IN(1,2)List all = cri.list();
Expression.and(Expression.eq("name","han"),Expression.eq("name","han")); [AND]
Expression.or(Expression.eq("name","han"),Expression.eq("name","han")); [OR]
