1. 샘플 코드

1-1. Map<String,Integer>

1-1-1. 메인 코드

       Map myMap = new HashMap();
        myMap.put("aa",13);
        myMap.put("ab",12);
        myMap.put("ac",11);
        System.out.println(myMap);
        Map newMap = sortByValue(myMap);
        System.out.println(newMap);

1-1-2. 추가 메소드

    public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K, V> map) {
        List<Entry<K, V>> list = new ArrayList<>(map.entrySet());
        list.sort(Entry.comparingByValue());

        Map<K, V> result = new LinkedHashMap<>();
        for (Entry<K, V> entry : list) {
            result.put(entry.getKey(), entry.getValue());
        }

        return result;
    }

1-1-3. 실행 결과

{aa=13, ab=12, ac=11}
{ac=11, ab=12, aa=13}

1-2. Map<Integer,String>

1-2-1. 샘플 코드

       Map myMap = new HashMap();
        myMap.put(11, "ac");
        myMap.put(12, "ab");
        myMap.put(13, "aa");
        System.out.println(myMap);
        Map newMap = sortByValue(myMap);
        System.out.println(newMap);

1-2-2. 추가 메소드

   public static LinkedHashMap<Integer, String> sortByValue(Map<Integer, String> map) {
        List<Integer> mapKeys = new ArrayList<>(map.keySet());
        List<String> mapValues = new ArrayList<>(map.values());
        Collections.sort(mapValues);
        Collections.sort(mapKeys);

        LinkedHashMap<Integer, String> sortedMap = new LinkedHashMap<>();

        Iterator<String> valueIt = mapValues.iterator();
        while (valueIt.hasNext()) {
            String val = valueIt.next();
            Iterator<Integer> keyIt = mapKeys.iterator();

            while (keyIt.hasNext()) {
                Integer key = keyIt.next();
                String comp1 = map.get(key);
                String comp2 = val;

                if (comp1.equals(comp2)) {
                    keyIt.remove();
                    sortedMap.put(key, val);
                    break;
                }
            }
        }
        return sortedMap;
    }

1-2-3. 실행 결과

{11=ac, 12=ab, 13=aa}
{13=aa, 12=ab, 11=ac}