对Map的key按升序进行排序

//对Map的key按升序进行排序
List<Map.Entry<Integer,Task>> mappingList = new ArrayList<Map.Entry<Integer, Task>>(map.entrySet());
Collections.sort(mappingList, new Comparator<Map.Entry<Integer, Task>>() {
@Override
public int compare(Entry<Integer, Task> o1, Entry<Integer, Task> o2) {
return o1.getKey().compareTo(o2.getKey());
}
});
for (Map.Entry<Integer, Task> mapping : mappingList) {
result.add(mapping.getValue());
}