Program:

* * * * * * *
* * *   * * *
* *       * *
*           *
* *       * *
* * *   * * *
* * * * * * *

• Program:

  public class StarPattern18
  {
      public static void main(String[] args)
      {
          int n = 4;
  
          // Upper half of the pattern
          for(int i=1; i<=n; i++)
          {
              // Left stars
              for (int j=1; j<=n-i+1; j++)
              {
                  System.out.print("* ");
              }
              // Spaces in between
              for(int j=1; j<2*(i-1); j++)
              {
                  System.out.print("  ");
              }
              // Right stars
              for(int j=1; j<=n-i+1; j++)
              {
                  if (i==1 && j==n) // Avoid duplicate stars in the first row
                      continue;
                  System.out.print("* ");
              }
              System.out.println();
          }
  
          // Lower half of the pattern
          for(int i=n-1; i>=1; i--)
          {
              // Left stars
              for(int j=1; j<=n-i+1; j++)
              {
                  System.out.print("* ");
              }
              // Spaces in between
              for(int j=1; j<2*(i-1); j++)
              {
                  System.out.print("  ");
              }
              // Right stars
              for(int j=1; j<=n-i+1; j++)
              {
                  if (i == 1 && j == n) // Avoid duplicate stars in the last row
                      continue;
                  System.out.print("* ");
              }
              System.out.println();
          }
      }
  }