Here are 2 functions to sort a Map by the value instead of the key.

SortMapByValue.java

/**
     * This method will return a sorted Map
     * @param unsortMap
     * @return 
     */
    private static Map<String, Integer> sortMapByValue(Map<String, Integer> unsortMap) {

        List<Map.Entry<String, Integer>> list = new LinkedList(unsortMap.entrySet());

        //sort list based on comparator
        Collections.sort(list, new Comparator() {

            @Override
            public int compare(Object o1, Object o2) {
                return ((Comparable) ((Map.Entry) (o1)).getValue()).compareTo(((Map.Entry) (o2)).getValue());
            }
        });

        //put sorted list back into a map
        Map<String, Integer> sortedMap = new LinkedHashMap();
        for (Map.Entry<String, Integer> entry : list) {
            sortedMap.put(entry.getKey(), entry.getValue());
        }
        return sortedMap;
    }

    /**
     * This method will return a sorted List.
     * 
     * @param unsortMap
     * @return 
     */
    private static List<Map.Entry<String, Integer>> sortMapByValueForList(Map<String, Integer> unsortMap) {

        List<Map.Entry<String, Integer>> sortedList = new ArrayList(unsortMap.entrySet());

        //sort list based on comparator
        Collections.sort(sortedList, new Comparator() {

            @Override
            public int compare(Object o1, Object o2) {
                return ((Comparable) ((Map.Entry) (o1)).getValue()).compareTo(((Map.Entry) (o2)).getValue());
            }
        });

        return sortedList;
    }