如何使用java寫Student類的功能

 package xin;
import java.util.Scanner;
public class Student {
  int number;
  String classnumber;
  int age;
  String name;
  String sex;
  
  Student(int x,String y,int z,String p){
  	number = x;
  	classnumber = y;
  	age = z;
  	name = p;
  }
   int getNumber() {
  	return number; //返回學號
  }
   String getSClassnumber() {
  	return classnumber; //返回班號
  }
   int getAge() {
  	return age;   //返回年齡
  }
   String getName() {
  	 return name;  //返回姓名
   }
   String getSex() {
  	 return sex;  //返回性別
   }
  public String toString() {  	
  return "學號:"+number+" 班號:"+classnumber+" 姓名:"+name+" 性別:"+sex+" 年齡:"+age;
  }
  public static void main(String args[]) {
	  boolean boo,a;
	  int number1,age1;
	  String classnumber1,st;
	  String name1,sex1;
	  Student stu = new Student(1,"s",1,"xaio");
	  Scanner reader = new Scanner(System.in);
	  System.out.println("請輸入學號、班號、姓名、性別、年齡:");
	  stu.number = reader.nextInt();
	  stu.classnumber = reader.next();
	  stu.name = reader.next();
	  stu.sex = reader.next();
	  stu.age = reader.nextInt();
	  st = stu.toString();
	  System.out.println(st);
	  System.out.println("是否修改該學生信息？");
	  System.out.println("如果修改則輸入true,反之false");
	  a = reader.nextBoolean(); 
	  if(a) {
		  System.out.println("請輸入學號、班號、姓名、性別、年齡:");
		  number1 = reader.nextInt();
		  classnumber1 = reader.next();
		  name1 = reader.next();
		  sex1 = reader.next();
		  age1 = reader.nextInt();		  
	  System.out.println("學號:"+number1+" 班號:"+classnumber1+
			   " 姓名:"+name1+" 性別:"+sex1+" 年齡:"+age1);
  }
	  else
	  {System.out.println("繼續執行下一步");}
   System.out.println("輸入true繼續，false退出"); 
    boo = reader.nextBoolean();
   System.out.println("*********************");
   if(boo) {
  	 main(args);  //函數調用
   }
   else
  	 System.out.println("程序無法執行!!!!");
  }
}