Java集合的排序

import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.junit.Test;

public class StackDome {

    
    @Test
    public void sortTest() {
        /**
         * 单条件排序
         */
        List<User> users = new CopyOnWriteArrayList<User>();
        int count = 0;
        final int IDS = 10000;
        do {
            // 随机生产1到100范围的随机数
            int random = (int) (1 + Math.random() * (100 - 1 + 1));
            int randomId = (int) (1 + Math.random() * (11 - 1 + 1));
            users.add(new User(String.valueOf("sound" + count), random, IDS + randomId));
            count++;
        } while (count < 10);

        // 排序前,单独获取年龄
        // Set<Integer> userAges =
        // users.stream().map(User::getUserAge).collect(Collectors.toSet());
        // userAges.forEach(s->{System.out.println(s);});
        users.forEach(s -> {
            System.out.println("排序前====》名字" + s.getUserName() + ",年龄：" + s.getUserAge()+","+s.getId());
        });
        // 按照年龄进行排序。从小到大{升序}
        Collections.sort(users, new Comparator<User>() {
            @Override
            public int compare(User o1, User o2) {
                int compare = Integer.compare(o1.getUserAge(), o2.getUserAge());
                return compare;
            }
        });
        // 排序后
        users.forEach(s -> {
            System.err.println("排序后====》名字" + s.getUserName() + ",年龄：" + s.getUserAge()+","+s.getId());
        });
         //
        //补充：
        /**
         * 多条件排序是根据优先级去判断，如果年龄相等，则再根据ID去比较 这里用年龄作为优先级，
         */
        Collections.sort(users, new Comparator<User>() {
            @Override
            public int compare(User o1, User o2) {
                int compare = Integer.compare(o1.getUserAge(), o2.getUserAge());
                if (compare == 0) {
                    compare = Integer.compare(o1.getId(), o2.getId());
                }
                return compare;
            }
        });
        users.forEach(s -> {
            System.out.println("双条件排序====》名字" + s.getUserName() + ",年龄：" + s.getUserAge()+","+s.getId());
        });
    }
}
class User {
    private int userAge;
    private String userName;
    private int id;

    public User(String userName, int userAge, int id) {
        this.userName = userName;
        this.userAge = userAge;
        this.id = id;
    }

    public int getUserAge() {
        return userAge;
    }

    public void setUserAge(int userAge) {
        this.userAge = userAge;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

}

运行效果：
排序前====》名字sound0,年龄：96,10003
排序前====》名字sound1,年龄：58,10001
排序前====》名字sound2,年龄：59,10007
排序前====》名字sound3,年龄：46,10004
排序前====》名字sound4,年龄：6,10011
排序前====》名字sound5,年龄：61,10004
排序前====》名字sound6,年龄：24,10001
排序前====》名字sound7,年龄：24,10007
排序前====》名字sound8,年龄：10,10006
排序前====》名字sound9,年龄：47,10008
排序后====》名字sound4,年龄：6,10011
排序后====》名字sound8,年龄：10,10006
排序后====》名字sound6,年龄：24,10001
排序后====》名字sound7,年龄：24,10007
排序后====》名字sound3,年龄：46,10004
排序后====》名字sound9,年龄：47,10008
排序后====》名字sound1,年龄：58,10001
排序后====》名字sound2,年龄：59,10007
排序后====》名字sound5,年龄：61,10004
排序后====》名字sound0,年龄：96,10003
双条件排序====》名字sound4,年龄：6,10011
双条件排序====》名字sound8,年龄：10,10006
双条件排序====》名字sound6,年龄：24,10001
双条件排序====》名字sound7,年龄：24,10007
双条件排序====》名字sound3,年龄：46,10004
双条件排序====》名字sound9,年龄：47,10008
双条件排序====》名字sound1,年龄：58,10001
双条件排序====》名字sound2,年龄：59,10007
双条件排序====》名字sound5,年龄：61,10004
双条件排序====》名字sound0,年龄：96,10003