如何在java中确定排序数组中某些元素的索引？

public class BinarySearch {
    public static int search(int[] arr, int target) {
        int left = 0;
        int right = arr.length - 1;

        while (left <= right) {
            int mid = (left + right) / 2;

            if (arr[mid] == target) {
                return mid;
            } else if (arr[mid] > target) {
                right = mid - 1;
            } else {
                left = mid + 1;
            }
        }

        return -1;
    }

    public static void main(String[] args) {
        int[] arr = {1, 2, 3, 4, 5, 6, 7, 8, 9};
        int target = 6;
        int index = search(arr, target);
        if (index != -1) {
            System.out.println("目标元素的索引为：" + index);
        } else {
            System.out.println("未找到目标元素");
        }
    }
}