比较器排序TreeSet

import java.util.Comparator;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;

public class Demo04 {
    public static void main(String[] args) {
        Set<Cat1> s = new TreeSet<>(new Comparator<Cat1>() {
            @Override
            public int compare(Cat1 o1, Cat1 o2) {
                if(o1.getName().length() != o2.getName().length())
                    return o1.getName().length() - o2.getName().length();
                else 
                    if(o1.getAge() != o2.getAge())
                        return o1.getAge() - o2.getAge();
                    else 
                       return o1.getName().compareTo(o2.getName());
            }
        });
        s.add(new Cat1("豆包",20));
        s.add(new Cat1("沙包",20));
        s.add(new Cat1("菜鹤包",2));
        s.add(new Cat1("土包",2));
        s.add(new Cat1("大傻包",21));
        s.add(new Cat1("和包",4));
        s.add(new Cat1("豆沙包",2));
        System.out.println("s = " + s);
    }
}

class Cat1 {
    private String name;
    private Integer age;

    public Cat1(String name, Integer age) {
        this.name = name;
        this.age = age;
    }

    public Cat1() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Cat1{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}