code: private Map<K, V> sortByKey(Map<K, V> sourceMap, final int growthPattern) {
          List<Entry<K, V>> list = new ArrayList<Entry<K, V>>(
                  sourceMap.entrySet());
          Collections.sort(list, new Comparator<Entry<K, V>>() {
  
              @Override
              public int compare(Entry<K, V> o1, Entry<K, V> o2) {
                  K k1 = o1.getKey();
                  K k2 = o2.getKey();
                  return compareValue(k1, k2) * growthPattern;
              }
          });
  
          Map<K, V> desMap = new LinkedHashMap<K, V>();
          for (int i = 0; i < list.size(); i++) {
              Entry<K, V> item = list.get(i);
              desMap.put(item.getKey(), item.getValue());
          }
          return desMap;
      }
docs: 根据map中key进行排序
  
  @param sourceMap
  要排序 map
  @param growthPattern
  排序规则，升序或者降序
  @return 排序后 map