学生、大学生、研究生类

[java]代码库

import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
         Scanner scan = new Scanner(System.in);      
         int no = scan.nextInt();
         String name = scan.next();      
         String sex = scan.next();      
         Student s = new Student(no, name, sex);
         s.print();

         no = scan.nextInt();
         name = scan.next();      
         sex = scan.next();      
         String major = scan.next();
         CollegeStudent c = new CollegeStudent(no, name, sex, major);
         c.print();

         no = scan.nextInt();
         name = scan.next();      
         sex = scan.next();      
         major = scan.next();
         String supervisor = scan.next();
         GraduateStudent g = new GraduateStudent(no, name, sex, major, supervisor );
         g.print();
         g.doResearch();
         scan.close(); 
    }
}
class Student
{
	private int num;
	private String name;
	private String sex;
	public Student(int n, String na, String s)
	{
		num = n;
		name = na;
		sex = s;
	}
	public int getNum()
	{
		return num;
	}
	public String getName()
	{
		return name;
	}
	public String getSex()
	{
		return sex;
	}
	public void print()
	{
		System.out.println("no: "+num);
		System.out.println("name: "+name);
		System.out.println("sex: "+sex);
	}
}
class CollegeStudent extends Student
{
	private String major;
	public CollegeStudent(int n, String na, String s, String m)
	{
		super(n,na,s);
		major = m;
	}
	public String getMajor()
	{
		return major;
	}
	public void print()
	{
		System.out.println("no: "+super.getNum());
		System.out.println("name: "+super.getName());
		System.out.println("sex: "+super.getSex());
		System.out.println("major: "+major);
	}
}
class GraduateStudent extends CollegeStudent
{
	private String supervisor;
	public GraduateStudent(int n, String na, String s, String m, String su)
	{
		super(n,na,s,m);
		supervisor = su;
	}
	public void print()
	{
		System.out.println("no: "+super.getNum());
		System.out.println("name: "+super.getName());
		System.out.println("sex: "+super.getSex());
		System.out.println("major: "+super.getMajor());
		System.out.println("supervisor: "+supervisor);
	}
	public void doResearch()
	{
		System.out.println(super.getName()+" is doing research");
	}
}