How to reverse characters through exchange in java

package net.javaguides.corejava.string;
/**
* 
* @author Ramesh Fadatare
*
*/
public class ReverseStringWithSwaps {
public static void main(String[] args) {
ReverseStringWithSwaps stringWithSwaps = new ReverseStringWithSwaps();
stringWithSwaps.reverseWithSwaps("javaguides");
}
public String reverseWithSwaps(String string) {
final char[] array = string.toCharArray();
final int length = array.length - 1;
final int half = (int) Math.floor(array.length / 2);
char c;
for (int i = length; i >= half; i--) {
c = array[length - i];
array[length - i] = array[i];
array[i] = c;
}
display(string, String.valueOf(array));
return String.valueOf(array);
}
private void display(String input, String output) {
System.out.println(" input string :: " + input);
System.out.println(" output string :: " + output);
}
}

input string :: javaguides
output string :: sediugavaj