Learning Java Program

import java.util.Scanner;
class pyramidShape
{
 public static void main(String[] args)
   {
     System.out.print("Enter number of rows: ");
     Scanner in = new Scanner(System.in);
     int num=in.nextInt();
     for(int i=1;i<=num;i++)
     {
          for(int j=num;j>=i;j--)
          {
           System.out.print(" ");
          }
          for(int m=1;m<=i*2-1;m++)
          {
           System.out.print("*");
           }
      System.out.print("\n");
     }             
   }
}