JAVA按行读取文件如何判断两行内容是否相同

HashMap<String,List<Integer>> hm = new HashMap<String,List<Integer>>();
        
        for (String s : text){
            if (hm.containsKey(s)){
                List<Integer> list = hm.get(s);
                list.add(index);
                hm.put(s, list);
            }
            else {
                List<Integer> list = new ArrayList<Integer>();
                list.add(index);
                hm.put(s, list);
            }
        }