Sorting map by value

Question

I need to sort a map by value, or just display its contents by value (in descending order). The value is an int. I'm using a treemap, but I'm guessing it's impossible to sort it by anything but the value...then again i'm not really sure.
I've tried so many things, but I'm not experienced with maps so I'm having trouble.
Thanks.

Answer 1

Here is a class I wrote which will return a list of map.entrys in the order your comparator requires. Unfortunately, there is no way to get a Map sorted by values, only keys.
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
public class MapValueSorter {
     public static <K, V> List<Map.Entry<K, V>> sortValues(Map<K, V> unsorted, Comparator<V> c) {
          List<Map.Entry<K, V>> orderedList = new ArrayList<Map.Entry<K, V>>();
          Comparator<Map.Entry<K, V>> entryComparator = new MapEntryValueComparator<K, V>(c);
          for(Map.Entry<K, V> entry : unsorted.entrySet()) {
               int insert = Collections.binarySearch(orderedList, entry, entryComparator);
               if(insert<0)
                    insert = 1-insert;
               orderedList.add(insert, entry);
          return orderedList;
     public static class MapEntryValueComparator<K, V> implements Comparator<Map.Entry<K, V>> {
          private Comparator<V> valueComparator = null;
          public MapEntryValueComparator(Comparator<V> c) {
               valueComparator = c;
          public int compare(Map.Entry<K, V> entry1, Map.Entry<K, V> entry2) {
               return valueComparator.compare(entry1.getValue(), entry2.getValue());
}