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