java输入学生成绩

public class Card {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int stu[] = new int[3];
try{
for(int i=0; i<stu.length;i++) {
Student s = new Student();
s.getStudent();
s.showStudent();
s.averStudent();
}
}catch (Exception e){
System.out.println("输入有误：");
}
}
}

class Student {
int id;
String name;
double a,b,c;
double avg;
Object e=null;

public void getStudent(){
Scanner keyboard=new Scanner(System.in);
System.out.println("请输入学号：");
id=keyboard.nextInt();
System.out.println("请输入姓名：");
name=keyboard.next();
System.out.println("请输入语文课成绩：");
a=keyboard.nextInt();
System.out.println("请输入数学课成绩：");
b=keyboard.nextInt();
System.out.println("请输入英语课成绩：");
c=keyboard.nextInt();
}
public void showStudent() {
System.out.println("学号："+id+" "+"姓名："+ name+" "+"语文课成绩："+a+" "+"数学课成绩："+b+" "+"英语课成绩："+c);
}
public void averStudent() {
avg=(a+b+c)/3;
System.out.println("三门课的平均成绩是："+avg);
}

}