Help Java, Map Descending Order

[yess_boss]

Hello guys, how can I sort out the values of  treemap in descending order? I think in default it is sorting the keys.

Map<L2PcInstance, Integer> newMap = new TreeMap<L2PcInstance, Integer>(Collections.reverseOrder());

[Tryskell]

In your case, TreeMap is useless (until you use ordered keys somewhere else).

 

I would say you have to take the values() of HashMap (which is a Collection) into a new list, and then

Collections.sort(arraylist, Collections.reverseOrder());

More infos here :

 

http://www.leveluplunch.com/java/examples/sort-order-map-by-values/

 

If you want to keep ALSO keys, you have to build a Comparator. See "Straight up Java" case.

Edited October 21, 2015 by Tryskell

[vampir]

public static Map<L2PcInstance, Integer> sortMap(Map<L2PcInstance, Integer> notSortedMap)

{

Map<L2PcInstance, Integer> orderedMap = new TreeMap<>(new MyOwnComparator(notSortedMap));

orderedMap.putAll(notSortedMap);

return orderedMap;

}

 

public static class MyOwnComparator implements Comparator<L2PcInstance>

{

private final Map<L2PcInstance, Integer> map;

 

public MyOwnComparator (Map<L2PcInstance, Integer> map)

{

this.map = map;

}

 

@Override

public int compare(L2PcInstance o1, L2PcInstance o2)

{

return Integer.compare(map.get(o1), map.get(o2));//Do whatever you want here. This line will currently compare the values

}

}