选择排序算法的JAVA实现

package Utils.Sort;

/**

*@author Linyco

*利用选择排序法对数组排序，数组中元素必须实现了Comparable接口。

*/

public class ChooseSort implements SortStrategy

{    /**

       *对数组obj中的元素以选择排序算法进行排序

       */

       public void sort(Comparable[] obj)

       {  if (obj == null)

              {    throw new NullPointerException("The argument can not be null!");

              }

              int index = 0;

              for (int i = 0 ;i < obj.length - 1 ;i++ )

              {    index = i;

                     tmp = obj[i];

                     for (int j = i + 1 ;j < obj.length ;j++ )