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How to sort a Map on the values in Java?

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I am relatively new to Java, and often find that I need to sort a Map<Key, Value> on the values. Since the values are not unique, I find myself converting the keySet into an array, and sorting that array through array sort with a custom comparator that sorts on the value associated with the key. Is there an easier way?

1Answer


0

Asuming Java ,you could sort hashmap just like this :

public LinkedHashMap sortHashMapByValuesD(HashMap passedMap) {
   List mapKeys = new ArrayList(passedMap.keySet());
   List mapValues = new ArrayList(passedMap.values());
   Collections.sort(mapValues);
   Collections.sort(mapKeys);

   LinkedHashMap sortedMap = new LinkedHashMap();

   Iterator valueIt = mapValues.iterator();
   while (valueIt.hasNext()) {
       Object val = valueIt.next();
       Iterator keyIt = mapKeys.iterator();

       while (keyIt.hasNext()) {
           Object key = keyIt.next();
           String comp1 = passedMap.get(key).toString();
           String comp2 = val.toString();

           if (comp1.equals(comp2)){
               passedMap.remove(key);
               mapKeys.remove(key);
               sortedMap.put((String)key, (Double)val);
               break;
           }

       }

   }
   return sortedMap;
}

Just a kick-off example , This way is more useful as it sorts the HashMap and keeps the duplicate values as well.

  • answered 2 years ago
  • Sunny Solu

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