帮我写一个java的快速排序算法

我可以给你一个快速排序算法的Java代码示例：

public class QuickSort {
public static void main(String[] args) {
int[] arr = {10, 7, 8, 9, 1, 5};
int n = arr.length;

QuickSort qs = new QuickSort();
qs.sort(arr, 0, n-1);

System.out.println("排序后的数组：");
qs.printArray(arr);
}

int partition(int arr[], int low, int high) {
int pivot = arr[high];
int i = (low-1);
for (int j=low; j<high; j++) {
if (arr[j] <= pivot) {
i++;

int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}

int temp = arr[i+1];
arr[i+1] = arr[high];
arr[high] = temp;

return i+1;
}

void sort(int arr[], int low, int high) {
if (low < high) {
int pi = partition(arr, low, high);

sort(arr, low, pi-1);
sort(arr, pi+1, high);
}
}

void printArray(int arr[]) {
int n = arr.length;
for (int i=0; i<n; ++i)
System.out.print(arr[i]+" ");
System.out.println();
}
}