1. 샘플 코드
1-1. Map<String,Integer>
1-1-1. 메인 코드
MapmyMap = 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
MapmyMap = 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}