java - Sort a list by frequency of strings in it -

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• sorting words in order of frequency? (least greatest) 4 answers

list is

list<string> list = new arraylist<string>();  list.add("apple"); list.add("ball"); list.add("apple"); list.add("cat"); list.add("ball"); 

now have sort list frequency of apple, ball, cat

i have output as:

apple ball cat 

first, count occurrence of string , sort using map

list<string> list = new arraylist<string>(); list.add("apple"); list.add("ball"); list.add("apple"); list.add("cat"); list.add("ball"); map<string, integer> map = new hashmap<string, integer>(); (string s : list) {     if (map.containskey(s)) {         map.put(s, map.get(s) + 1);     } else {         map.put(s, 1);     } } valuecomparator<string, integer> comparator = new valuecomparator<string, integer> (map); map<string, integer> sortedmap = new treemap<string, integer> (comparator); sortedmap.putall(map);  list<string> sortedlist = new arraylist<string> (sortedmap.keyset());  system.out.println(sortedmap); system.out.println(sortedlist);  }  static class valuecomparator<k, v extends comparable<v>> implements comparator<k> {  map<k, v> map;  public valuecomparator(map<k, v> base) {     this.map = base; }  @override public int compare(k o1, k o2) {      return map.get(o2).compareto(map.get(o1)); } }