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}