Quicksort problem

import java.util.*;

public class Main {

private int array[];
private int length;

public void sort(int[] inputArr) {
     
    if (inputArr == null || inputArr.length == 0) {
        return;
    }
    this.array = inputArr;
    length = inputArr.length;
    quickSort(0, length - 1);
}

private void quickSort(int lowerIndex, int higherIndex) {
     
    int i = lowerIndex;
    int j = higherIndex;
    
    int pivot = array[lowerIndex+(higherIndex-lowerIndex)/2];
    
    while (i <= j) {
       
        while (array[i] < pivot) {
            i++;
        }
        while (array[j] > pivot) {
            j--;
        }
        if (i <= j) {
            exchangeNumbers(i, j);
           
            i++;
            j--;
        }
	}
}

}
in this i am getting error ar exchange Numbers,please correct my code,i am stuck at it

Hey @karthik1989photos
write the code of exchangeNumbers(i,j) method