List 根據 元素屬性進行排序

`

package com.utils;


import java.util.*;


public class UserPaixu  {
    int age ;
    String name;

public UserPaixu(int age,String name){
    this.age = age;
    this.name = name;
}



@Override
public String toString() {
    return this.age+" "+this.name;
}

public static void main(String [] a){
    UserPaixu u1 = new UserPaixu(1,"z");
    UserPaixu u2 = new UserPaixu(11,"x");
    UserPaixu u3 = new UserPaixu(2,"c");
    UserPaixu u4 = new UserPaixu(33,"v");
    UserPaixu u5 = new UserPaixu(4,"b");
    UserPaixu u6 = new UserPaixu(15,"n");
    List<UserPaixu> list = new ArrayList<UserPaixu>();
    list.add(u3);
    list.add(u6);
    list.add(u1);
    list.add(u2);
    list.add(u4);
    list.add(u5);
    System.out.println("排序前:  " + list);
    
    System.out.println("*************************** ");
    Collections.sort(list, new Comparator<UserPaixu>() {
        @Override
        public int compare(UserPaixu o1, UserPaixu o2) {
            if (o1.age>o2.age){
                return 1;
            }
            if (o1.age==o2.age){
                return 0;
            }
            return -1;
        }

    });
    System.out.println("排序後:  " + list);
    }
 }
    // 輸出結果
    排序前:  [2 c, 15 n, 1 z, 11 x, 33 v, 4 b]
    *************************** 
    排序後:  [1 z, 2 c, 4 b, 11 x, 15 n, 33 v]

`