java - How to sort a TreeSet by Value? -

i pretty new treemap , treeset , likes , wondering how sort data structures value? realise treeset can sort alphabetical order automatically want order via value? idea on how this?

it prints like...

• aaa: 29
• aaahealthart: 30
• ab: 23
• abbey: 14
• abdomin: 3
• aberdeen: 29
• aberdeenuni: 20

when want print like...

• aaahealthart: 30
• aaa: 29
• aberdeen: 29
• ab: 23
• aberdeenuni: 20
• abbey: 14
• abdomin: 3

here method here...

arraylist<string> fullbagofwords = new arraylist<string>(); public map<string, integer> frequencyone;  public void termfrequency() throws filenotfoundexception{     collections.sort(fullbagofwords);     set<string> unique = new treeset<string>(fullbagofwords);     printwriter pw = new printwriter(new fileoutputstream(frequencyfile));     pw.println("words in tweets :   frequency of words");     (string key : unique) {         int frequency = collections.frequency(fullbagofwords, key);          system.out.println(key + ": " + frequency);         pw.println(key + ": " + frequency);         }     pw.close();     } 

thanks guys.

treemap orders key, don't think can use same implementation sort value. can achieve task different approach:

public map<string, integer> countwords(list<string> words) {     map<string, integer> result = new map<>();     (string word : words) {         if (result.containskey(word)) {             // word in map, increment count             int count = result.get(word) + 1;             result.put(word, count);         } else {             result.put(word, 1);         }     }      return result; } 

then need sort elements of resulting map. can in following way:

public list<map.entry<string, integer> sortmap(map<string, integer> map) {     list<map.entry<string, integer> elements = new linkedlist<>(map.entryset());     collections.sort(elements, new comparator<map.entry<string, integer>>() {          public int compare(map.entry<string, integer> o1, map.entry<string, integer> o2 ) {             return o1.getvalue().compareto(o2.getvalue());         }      }); } 

so use first method count word frequency , second sort it.