Compro: Shifting arrays k positions without using additional memory

Key idea :Swapping based

Naive method :Rotate the one be one(k times)
for example :{1,2,3,4} Rotate 2 left
{4,1,2,3}  Rotate 1 left
{3,4,1,2}  Rotate 0 left return..:)
O(nk) time, n is array length and k is number of rotation
----------------------
Improved method:Reverse-based
for example :{1,2,3,4} Rotate 2
Reverse {1,2} and {3,4} we get {2,1,4,3}
Reverse {2,1,4,3} we get {3,4,1,2}
O(n) time, n  is array length

package array;

public class RotateArray {

 int array[];

 public RotateArray(int array[]) {
  int i = 0;// for indexing array
  System.out.print("Input Array : ");
  this.array = new int[array.length];
  for (int a : array) {
   this.array[i++] = a;

  }
  printArray();
  System.out.println();
 }

 void rotateKPosNaive(int k) {
  for (int i = 0; i < k; i++)
   rotatebyOne();
  System.out.print("Rotated Array : ");
  printArray();
  System.out.println();

 }

 void rotateKPosAdv(int k) {
  reverse(0, k - 1);
  reverse(k, array.length - 1);
  reverse(0, array.length - 1);
  System.out.print("Rotated Array : ");
  printArray();

 }

 void reverse(int start, int end) {
  for (int i = start; i <= (start + end + 1) / 2; i++) {

   // swap(i,end-i+start);//is used with i<=(start+end)/2
   swap(i, end--);

  }
 }

 void printArray() {
  for (int a : array)
   System.out.print(a);
 }

 void rotatebyOne() {
  int temp = array[0];
  for (int i = 1; i < array.length; i++) {
   array[i - 1] = array[i];
  }
  array[array.length - 1] = temp;

 }

 void swap(int i, int j) {
  int temp = array[i];
  array[i] = array[j];
  array[j] = temp;

 }

 public static void main(String[] args) {
  int sample1[] = { 1, 2, 3, 4, 5, 6, 7 };

  new RotateArray(sample1).rotateKPosNaive(3);
  new RotateArray(sample1).rotateKPosAdv(3);

 }
}

Output:
Input Array : 1234567
Rotated Array : 4567123
Input Array : 1234567
Rotated Array : 4567123