【TreeSet：请按照姓名的长度排序】

package com.yjf.esupplier.common.test;

import java.util.TreeSet;

/**
 * @author shusheng
 * @description 请按照姓名的长度排序
 * @Email shusheng@yiji.com
 * @date 2018/12/17 10:36
 */
public class TreeSetDemo {

    public static void main(String[] args) {

        // 创建集合对象
        TreeSet<Student> ts = new TreeSet<Student>();

        // 创建元素
        Student s1 = new Student("linqingxia", 27);
        Student s2 = new Student("zhangguorong", 29);
        Student s3 = new Student("wanglihong", 23);
        Student s4 = new Student("linqingxia", 27);
        Student s5 = new Student("liushishi", 22);
        Student s6 = new Student("wuqilong", 40);
        Student s7 = new Student("fengqingy", 22);
        Student s8 = new Student("linqingxia", 29);
        // 添加元素
        ts.add(s1);
        ts.add(s2);
        ts.add(s3);
        ts.add(s4);
        ts.add(s5);
        ts.add(s6);
        ts.add(s7);
        ts.add(s8);

        // 遍历
        for (Student s : ts) {
            System.out.println(s.getName() + "---" + s.getAge());
        }

    }

}

class Student implements Comparable<Student> {

    private String name;
    private int age;

    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;
    }

    @Override
    public int compareTo(Student s) {

        int num1 = this.name.length() - s.name.length();
        int num2 = num1 == 0 ? this.name.compareTo(s.name) : num1;
        int num3 = num2 == 0 ? this.age - s.age : num2;

        return num3;
    }
}