利用java如何实现一个快速排序方法

    public static void main(String[] args) {    int a[] = { 49, 38, 65, 97, 76, 13, 27, 49, 78, 34, 12, 64, 5, 4,        62, 99, 98, 54, 56, 17, 18, 23, 34, 15, 35, 25, 53, 51 };    if (a.length > 0) {//查看数组是否为空        _quickSort(a, 0, a.length - 1);    }    System.out.println(Arrays.toString(a));  }  public static void _quickSort(int[] arr, int left, int right) {    if (left >= right) {      return;    }    int low = left;    int high = right;    int tmp = arr[low];//数组的第一个作为中轴      while (low < high) {      while (low < high && arr[high] >= tmp) {        high--;      }      arr[low] = arr[high];//比中轴小的记录移到低端        while (low < high && arr[low] <= tmp) {        low++;      }      arr[high] = arr[low];//比中轴大的记录移到高端      }    arr[low] = tmp;//中轴记录到尾      _quickSort(arr, left, low - 1);//对低字表进行递归排序      _quickSort(arr, low + 1, right);//对高字表进行递归排序    }