how to create unit matrix in java of arbritary dimensions

import java.util.*;
class  UnitMatrix
{
    public static int[][] create(int size) {
    int[][] matrix = new int[size][size];
    for(int i = 0; i < size; i++)
      for(int j = 0; j < size; j++)
        matrix[i][j] = (i == j) ? 1 : 0;
    return matrix;
  }

    public static void main(String[] args) 
    {
        Scanner input=new Scanner(System.in);
        System.out.println("Enter size of matrix: ");
        int size=input.nextInt();
        int matrix[][]=create(size);

        for (int i=0 ; i < matrix.length ; i++)
        {     System.out.println();
            for  (int j=0 ; j < matrix[i].length ; j++){
                System.out.print(matrix[i][j]+" ");
                  }
        }

    }
}