check the following code   public class MergeSort {            // The mergeSort method returns a sorted copy of the      // String objects contained in the String array data.      /**       * Sorts the String objects using the merge sort algorithm.       *        * @param data the String objects to be sorted       * @return the String objects sorted in ascending order       */      public static String[] mergeSort(String[] data) {            if (data.length > 1) {          String[] left = new String[data.length / 2];          String[] right = new String[data.length - left.length];          System.arraycopy(data, 0, left, 0, left.length);          System.arraycopy(data, left.length, right, 0, right.length);                  left = mergeSort(left);          right = mergeSort(right);                  return merge(left, right);                  }        else {          return data;        }              }            /**       * The merge method accepts two String arrays that are assumed       * to be sorted in ascending order. The method will return a       * sorted array of String objects containing all String objects       * from the two input collections.       *        * @param left a sorted collection of String objects       * @param right a sorted collection of String objects       * @return a sorted collection of String objects       */      public static String[] merge(String[] left, String[] right) {                String[] data = new String[left.length + right.length];                int lIndex = 0;        int rIndex = 0;                for (int i=0; i