Java How to print a Pyramid

A Java example to print half and full pyramid, for fun.

package com.mkyong;
import java.util.Collections;
public class CreatePyramid {
    public static void main(String[] args) {
        int rows = 5;
        System.out.println("\n1. Half Pyramid\n");
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print("*");
            System.out.println("");
        System.out.println("\n2. Full Pyramid\n");
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < rows - i; j++) {
                System.out.print(" ");
            for (int k = 0; k <= i; k++) {
                System.out.print("* ");
            System.out.println("");
        //java 8 , one line
        System.out.println("\n3. Full Pyramid (Compact)\n");
        for (int i = 0; i < rows; i++) {
            System.out.println(String.join("", Collections.nCopies(5 - i - 1, " "))
                    + String.join("", Collections.nCopies(2 * i + 1, "*")));
        // java 8
        System.out.println("\n4. Inverted Pyramid\n");
        for (int i = rows; i > 0; i--) {
            System.out.println(String.join("", Collections.nCopies(5 - i, " "))
                    + String.join("", Collections.nCopies(2 * i - 1, "*")));

Output

1. Half Pyramid
**
***
****
*****
2. Full Pyramid
     * 
    * * 
   * * * 
  * * * * 
 * * * * * 
3. Full Pyramid (Compact)
   ***
  *****
 *******
*********
4. Inverted Pyramid
*********
 *******
  *****
   ***

References

1. Collections.nCopies JavaDoc
2. Python – Print a pyramid