使用java在菱形图案中打印菱形图案

Question

I want to print out a pattern like this but I can't get it to work. The big problem I'm having is the lines outside the diamond and the parts in the diamond where there is just spaces. I have marked my output white different numbers to mark areas so i know what part who is doing what. I hope someone can help please.

Here is my code:

public static void main(String[] args) {

        int rows1 = 10;
        System.out.println("## Printing the pattern ##");

        for (int i=1; i<=rows1; i++)
        {
            // Print space in decreasing order övre väster hörn tomrum
            for (int j=rows1; j>i; j--)
            {
                System.out.print(" 1 ");
            }


            // Print star in increasing order övre inre delen av triangeln tomrum
            for (int k=1; k<=(i * 2) -1; k++)
            {
                if( k == 1 || k == (i * 2) -1)
                    System.out.print("*");
                else
                    System.out.print(" 2 ");
            }
            System.out.println();
        }
        for (int i=rows1-1; i>=1; i--)
        {
         // Print space in increasing order nedre västra härnet tomrum
            for (int j=rows1-1; j>=i; j--)
            {
                System.out.print(" 3 ");
            }
            // Print star in decreasing order nedre inre delen av triangeln
            for (int k=1; k<=(i * 2) -1; k++)
            {
                if( k == 1 || k == (i * 2) -1 )
                    System.out.print("*");
                else
                    System.out.print(" 4 ");
            }


            System.out.println();
        }

}

How I want it to look or near it

Answer 1

This class prints the image in the picture. Basic idea is that you use the (left part of) the middle line of the diamond, to create the rest of the form.

public class Diamond {

    private String base;

    public Diamond(String base) {
        this.base = base;
    }

    private String reverse(String s) {
        return new StringBuilder(s).reverse().toString();
    }

    public void print() {

        int l = base.length();
        int c = (l/2)-1;

        String[] diamond = new String[l-1];
        diamond[c] = base + " " + reverse(base);

        String next = "/ " + base;
        for (int i = 1; i < l/2; i++) {

            String center = " ";
            if (next.endsWith("  ") == false) {
                center = "O";
            }

            next = next.substring(0, l);
            String bottom = next.replace('/', '\\');
            String bottomRight = reverse(next);
            String right = bottomRight.replace('/', '\\');

            diamond[c-i] = next + center + right;
            diamond[c+i] = bottom + center + bottomRight;

            next = "  " + next;
        }

        for (String line : diamond) {
            System.out.println(line);
        }
    }

    public static void main(String[] args) {
        new Diamond("  O O O O O     O O O       ").print();
    }
}