code: public void set1Value(int index, String newValue) {
          try {
              value.set( index, newValue );
          }
          catch (IndexOutOfBoundsException e) {
              Log.e(TAG, "X3D MFString set1Value(int index, ...) out of bounds." + e);
          }
          catch (Exception e) {
              Log.e(TAG, "X3D MFString set1Value(int index, ...)  exception " + e);
          }
      }
docs: Replace a single value at the appropriate location in the existing value array.
  @param index - location in the array list
  @param newValue - the new String