题目

定义学生对象，存储到集合中，按照姓名长度来存，长度相同比较名字大小，随后比较年龄

分析

使用 双链集合中的 TreeMap来存
注意：使用比较器来比较或者实现Comparable接口，重写compareTo这个方法

程序代码

//学生类
package com.company.test;

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;
    }

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

}

package com.company.test;


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

public class MyTest {
    public static void main(String[] args) {
        TreeMap<Student, String> map = new TreeMap<>(new Comparator<Student>() {
            @Override
            public int compare(Student s1, Student s2) {
                //按照姓名长度来排序
                int num=s1.getName().length()-s2.getName().length();
                int num2=num==0?s1.getName().compareTo(s2.getName()):num;
                int num3=num2==0?s1.getAge()-s2.getAge():num2;
                return num3;
            }
        });
        map.put(new Student("貂蝉", 19), "001");
        map.put(new Student("杨玉环", 23), "002");
        map.put(new Student("赛西施", 24), "003");
        map.put(new Student("王昭君", 30), "004");
        map.put(new Student("李白", 24), "003");
        map.put(new Student("韩信", 30), "004");
        Set<Student> stu= map.keySet();
        for (Student student : stu) {
            System.out.println(student.getAge() + "===" + student.getName() + "========" + map.get(student));
        }
    }
}