private void genTextMaps(){
		Session session = sessionFactory.openSession();
		session.beginTransaction();
		Query q1 = session.createQuery("from Intro_learn");
		@SuppressWarnings("unchecked")
		List<Intro_learn> list_intro = q1.list();
		Intro_learn intro = new Intro_learn();
		
		String introduction;
		text_cls tc;
		cls_cls cc;
		
		for(int i=0;i<list_intro.size();i++){
			intro = list_intro.get(i);
			introduction = intro.getIntroduction();
			list_text.clear();
			list_cls.clear();
			try{
				StrHandler.introString2array(introduction, list_text,  list_cls);
			}catch(Exception e){
				System.out.println(introduction);
			}
			for(int j=0;j<list_text.size()-1;j++){
				tc = new text_cls();
				cc = new cls_cls();
				tc.text=list_text.get(j);
				tc.cls=list_cls.get(j);
				cc.cls1=list_cls.get(j);
				cc.cls2=list_cls.get(j+1);
				if(cls_map.containsKey(list_cls.get(j)))
					cls_map.put(list_cls.get(j), cls_map.get(list_cls.get(j))+1);
				else
					cls_map.put(list_cls.get(j),1);
				if(text_cls_map.containsKey(tc))
					text_cls_map.put(tc, text_cls_map.get(tc)+1);
				else
					text_cls_map.put(tc, 1);
				if(cls_cls_map.containsKey(cc))
					cls_cls_map.put(cc, cls_cls_map.get(cc)+1);
				else
					cls_cls_map.put(cc, 1);
			}
		}
		Iterator<Entry<text_cls , Integer>> iter = text_cls_map.entrySet().iterator(); 
		Entry<text_cls , Integer> entry;
		while (iter.hasNext()) { 
            entry = iter.next(); 
            if(entry.getValue()>10){
                if(!distc_text.contains((entry.getKey()).getText()))
                	distc_text.add((entry.getKey()).getText());
            }
        }
		
		session.flush();
		session.clear();
		session.getTransaction().commit();
		session.close();
	}