//传入一个Map<String,Long>  返回它按value排序后的结果 sort为正序还是倒序（-1倒序），size为要几条数据
    private static Map<String, Long> sortMapByValues(Map<String, Long> aMap, int sort, int size) {

        Set<Map.Entry<String, Long>> mapEntries = aMap.entrySet();

        List<Map.Entry<String, Long>> aList = new LinkedList<Map.Entry<String, Long>>(mapEntries);

        Collections.sort(aList, new Comparator<Map.Entry<String, Long>>() {

            @Override
            public int compare(Map.Entry<String, Long> ele1,
                               Map.Entry<String, Long> ele2) {
                if (sort < 0) {
                    return ele2.getValue().compareTo(ele1.getValue());
                }
                return ele1.getValue().compareTo(ele2.getValue());
            }
        });
        // Storing the list into Linked HashMap to preserve the order of insertion.
        Map<String, Long> aMap2 = new LinkedHashMap<String, Long>();
        for (Map.Entry<String, Long> entry : aList) {
            aMap2.put(entry.getKey(), entry.getValue());
            if (aMap2.size() == size) {
                break;
            }
        }
        return aMap2;
    }