Nullexception error when trying to populate array list

Question

I am extremely new with java. I have been working on a project and am completely stumped.

What I am trying to do is I need to build a application that generates an ArrayList of certain students and grades, and then i will be able to manipulate them from there.

I thought I had it down to where I could get it to create the object at the very least, but it looks like that is not the case. It compiles correctly, but when I try to create the object using the Student() constructor with no arguments it gives me the following stack trace:

java.lang.NullPointerException
    at Student.addInitialStudents(Student.java:61)
    at Student.<init>(Student.java:23)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at bluej.runtime.ExecServer$3.run(ExecServer.java:759)

from reading the stack trace it looks like the issue is in my constructor.

import java.util.ArrayList;

public class Student
{ 
    public ArrayList<Student> students = new ArrayList<Student>();
    private String studentID;
    private String firstName;
    private String lastName;
    private String email;
    private int age;
    private int grade1;
    private int grade2;
    private int grade3;
    private int[][] grades;
    private int i;
    private int x;

    /**
     * Constructor for objects of class Student
     */
    public Student(){
        addInitialStudents();
    }

    public Student(String studentID, String firstName, String lastName, String email, int age, int[][] grades)
    {
        this.studentID = studentID;
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
        this.age = age;
        this.grades = grades;
    }

    private void addInitialStudents(){
        String[] id = {"1","2","3","4","5"};
        String[] fName = {"John", "Suzan", "Jack", "Erin", "Sam"};
        String[] lName = {"Smith", "Erickson", "Napoli", "Black", "smith"};
        String[] mail = {"John1989@gmail.com","Erickson_1990@gmailcom","The_lawyer99yahoo.com","Erin.black@comcast.net","ssmith@gmail.com"};
        int[] listAge = {20, 19, 19 ,22, 28};
        int[][] iniGrades =
        {
            {88, 79, 59},
            {91, 72, 85},
            {85, 84, 87},
            {91, 98, 82},
            {99, 87, 92}
        };

        for (i = 0; i <= 4; i++){

            studentID = id[i];
            firstName = fName[i];
            lastName = lName[i];
            email = mail[i];
            age = listAge[i];

            for (x = 0; x <= 2; x++){
                grades[i][x] = iniGrades[i][x];
            }


            students.add(new Student(studentID, firstName, lastName, email, age, grades));

        }

    }

    public void getID(){
        System.out.print(students.get(0));
    }

}

Anyone have any tips on this?

BlueJ is highlighting the line

grades[i][x] = iniGrades[i][x];

I'm sorry if this is a duplicate, but I couldn't find a solution no matter how much research i tried to do and no matter how many changes I make.