如何使用java写Student类的功能

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; //返回学号

   }

    String getSClassnumber() {

     return classnumber; //返回班号

   }

    int getAge() {

     return age;   //返回年龄

   }

    String getName() {

      return name;  //返回姓名

    }

    String getSex() {

      return sex;  //返回性别

    }

   public String toString() {   

   return "学号:" +number+ " 班号:" +classnumber+ " 姓名:" +name+ " 性别:" +sex+ " 年龄:" +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( "请输入学号、班号、姓名、性别、年龄:" );

       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( "是否修改该学生信息？" );

       System.out.println( "如果修改则输入true,反之false" );

       a = reader.nextBoolean();

       if (a) {

           System.out.println( "请输入学号、班号、姓名、性别、年龄:" );

           number1 = reader.nextInt();

           classnumber1 = reader.next();

           name1 = reader.next();

           sex1 = reader.next();

           age1 = reader.nextInt();       

       System.out.println( "学号:" +number1+ " 班号:" +classnumber1+

                " 姓名:" +name1+ " 性别:" +sex1+ " 年龄:" +age1);

   }

       else

       {System.out.println( "继续执行下一步" );}

    System.out.println( "输入true继续，false退出" );

     boo = reader.nextBoolean();

    System.out.println( "*********************" );

    if (boo) {

      main(args);  //函数调用

    }

    else

      System.out.println( "程序无法执行!!!!" );

   }

}