Java中比较器Comparator的使用

public class Student {
    private String name;
    private int age;
    public Student() {
    }
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }

import java.util.Comparator;
import java.util.TreeSet;
public class TreeSetDemo {
    public static void main(String[] args) {
        //创建集合对象
        TreeSet<Student> ts = new TreeSet<Student>(new Comparator<Student>() {
            @Override
            public int compare(Student s1, Student s2) {
                int num = s1.getAge() - s2.getAge();
                int num2 = num == 0 ? s1.getName().compareTo(s2.getName()) : num;
                return num2;
            }
        });
        //创建学生对象
        Student s1 = new Student("xishi", 30);
        Student s2 = new Student("wangzhanjun", 28);
        Student s3 = new Student("diaochan", 31);
        Student s4 = new Student("yangyuhuan", 33);
        //把学生添加到集合
        ts.add(s1);
        ts.add(s2);
        ts.add(s3);
        ts.add(s4);
        for (Student s : ts) {
            System.out.println(s.getName() + "," + s.getAge());
        }
    }
}