student实体类代码如下所示：

package com.test.Test10;


public class StudentNiMingLei{
    private int age;
    private String name;

    public int getAge() {
        return age;
    }

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


    public String getName() {
        return name;
    }

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

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

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


}


测试类代码如下所示：

package com.test.Test10;

import java.util.Comparator;
import java.util.TreeSet;

public class Test03NiMingLei {
    public static void main(String[] args) {
        //创建一个TreeSet
        //匿名内部类
  
        TreeSet<StudentNiMingLei> ts = new TreeSet<>(new Comparator<StudentNiMingLei>() {
            @Override
            public int compare(StudentNiMingLei o1, StudentNiMingLei o2) {
                return o1.getName().compareTo(o2.getName());
            }
        }); //一旦指定外部比较器，那么就会按照外部比较器来比较
        ts.add(new StudentNiMingLei(10,"elili"));
        ts.add(new StudentNiMingLei(8,"blili"));
        ts.add(new StudentNiMingLei(4,"alili"));
        ts.add(new StudentNiMingLei(9,"clili"));
        ts.add(new StudentNiMingLei(10,"elili"));
        ts.add(new StudentNiMingLei(1,"dlili"));
        System.out.println(ts.size()); //放了6个数据，出来了5个，重复的删除了
        System.out.println(ts);        //[Student{age=4, name='alili'}, Student{age=8, name='blili'}, Student{age=9, name='clili'}, Student{age=1, name='dlili'}, Student{age=10, name='elili'}]  按照name值的升序进行排列了
    }
}