java map实现排序功能

public static void main(String[] args) {

Map<String, String> map = new HashMap<String, String>();

map.put("2", "ccccc");

map.put("1", "aaaaa");

map.put("4", "bbbbb");

map.put("3", "ddddd");

List<Map.Entry<String,String>> list = new ArrayList<Map.Entry<String,String>>(map.entrySet());

Collections.sort(list,new Comparator<Map.Entry<String,String>>() {
//升序排序 比较器
@Override
public int compare(Entry<String, String> o1, Entry<String, String> o2) {
return o1.getKey().compareTo(o2.getKey());
}

});

for(Map.Entry<String,String> mapping:list){

System.out.println(mapping.getKey()+":"+mapping.getValue());

}
}