java Map對象排序demo

import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map.Entry;

class User {
	String name;
	int age;

	public User(String name, int age) {
		this.name = name;
		this.age = age;
	}
	@Override
	public String toString() {
		return "name:"+name+"  age:"+age;
	}
}
public class ListDemo {

	public static void main(String[] args) {
		HashMap<Integer, User> map = new HashMap<Integer, User>();
		map.put(1, new User("jack", 20));
		map.put(2, new User("jery", 32));
		map.put(3, new User("jack", 17));
		map.put(4, new User("jack", 12));
		map.put(5, new User("jack", 28));
		LinkedList<Entry<Integer, User>> list = new LinkedList<>(map.entrySet());
		Collections.sort(list ,new Comparator<Entry<Integer, User>>() {
			@Override
			public int compare(Entry<Integer, User> o1, Entry<Integer, User> o2) {
				return o2.getValue().age -  o1.getValue().age;
			}
		});</span>
		for (int i = 0; i < list.size(); i++) {
			System.out.println(list.get(i).getValue().toString());
		}
	}
}