map自定义排序

package com.test;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Set;

import sun.util.resources.cldr.CalendarData;
public class test1 {

    public static void main(String[] agrs) throws ParseException{
        Map<String,Integer> map = new HashMap<>();
        map.put("a", 0);
        map.put("b", 1);
        map.put("c", -1);
        Set<String> set = map.keySet();
        for (String string : set) {
            System.out.println(map.get(string));
        }
        //对MAP按照值进行自定义排序  
        List<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String,Integer>>(map.entrySet());  
        System.out.println(list);
        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {

            @Override
            public int compare(Entry<String, Integer> o1, Entry<String, Integer> o2) {
                return o1.getValue().compareTo(o2.getValue());
            }
        });
        for (Entry<String, Integer> entry : list) {
            System.out.println(entry.getKey());
        }
    }

}

输出：
0
1
-1
[a=0, b=1, c=-1]
c
a
b