函数接口定义： class Student{ } 裁判测试程序样例： import java.util.ArrayList; public class Main{ private ArrayList slist = new ArrayList(); public void addStudent(Student s){ this.slist.add(s); } public void showStudent(){ for(Student s:slist){ System.out.println(s); } } public static void main(String[] args) { Main t = new Main(); t.addStudent(new Student("2016001","rose",18)); t.addStudent(new Student("2016002","hunifu",19)); t.addStudent(new Student("2016003","britsh",20)); t.addStudent(new Student("2016004","sunni",17)); t.showStudent(); } } /* 请在这里填写答案 */

这段代码中，需要定义一个`Student`类，包含学号、姓名和年龄三个属性。可以使用以下代码实现：

class Student{
    private String id;
    private String name;
    private int age;
    
    public Student(String id, String name, int age){
        this.id = id;
        this.name = name;
        this.age = age;
    }
    
    @Override
    public String toString(){
        return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
    }
}

然后在`Main`类中定义`addStudent()`方法和`showStudent()`方法，用于添加学生和展示学生信息。完整代码如下：

import java.util.ArrayList;

public class Main{
    private ArrayList<Student> slist = new ArrayList<>();

    public void addStudent(Student s){
        this.slist.add(s);
    }

    public void showStudent(){
        for(Student s: slist){
            System.out.println(s);
        }
    }

    public static void main(String[] args) {
        Main t = new Main();
        t.addStudent(new Student("2016001","rose",18));
        t.addStudent(new Student("2016002","hunifu",19));
        t.addStudent(new Student("2016003","britsh",20));
        t.addStudent(new Student("2016004","sunni",17));
        t.showStudent();
    }
}

这样就可以创建`Main`对象并调用`addStudent()`方法来添加学生，然后调用`showStudent()`方法来展示学生信息。