java List 排序，升序，降序

import java.util.*;


public class EntrySets {

    public static void main(String[] args) {
        Map<Object, Object> map = new HashMap<Object, Object>();
        map.put("k1", "v1");
        map.put("k2", "v2");
        getItem(map);
        List<Object> kk = new ArrayList<Object>();
        kk.add("1");
        kk.add("aa");
        kk.add("A");
        print(sortList(kk));

    }


    static void getItem(Map map) {
        map.forEach((key, value) -> print(key + ":" + value));
    }

    static void iterByKey(Map map) {
        /**  iter map  by key */
        for (Object k : map.keySet()) {
            String v = map.get(k).toString();
        }
    }

    static void print(Object o) {
        System.out.println(o);
    }

    static  List sortList(List list){
        Collections.sort(list);
        // 反转
        //Collections.reverse(list);
        return  list ;
    }
}