Test Program That Prompt User To Enter N And Displays N-by-b Matrix

I did a problem from my book which is "Write a method that displays an n-by-n matrix. Each element is 0 or 1, which is generate randomly. Write a test program that prompts the user to enter n and displays the n-by-b matrix".

So if a user would enter 3, and output could be 0 1 1
0 1 0
1 0 1

So here's my question... I was able to get the program to work in the way my book describes (by just writing the code in the class with the main), but for practice, I want to learn how to do this OOP-style...

I'm not sure how to do this, though, since the method is a void method, so I can't seem to call it within a toString method.

import java.util.Scanner;
public class MatrixTest {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter an int");
int number = input.nextInt();
MatrixClass mc = new MatrixClass(number);

[Code] .....