java二分法查找法

public class BinarySearch {
    public static void main(String[] args) {
        int[] arr = {
            1,
            3,
            5,
            6,
            7,
            8,
            11,
            13,
            14,
            15,
            16,
            17,
            20
        };
        System.out.println(binarySearch(arr, 14));
    }
    public static int binarySearch(int[] arr, int i) {
        if (arr.length == 0) return -1;
        int startPos = 0;
        int endPos = arr.length - 1;
        int m = (startPos + endPos) / 2;
        while (startPos <= endPos) {
            if (arr[m] == i) return m;
            if (arr[m] > i) {
                endPos = m - 1;
            } else if (arr[m] < i) {
                startPos = m + 1;
            }
            m = (startPos + endPos) / 2;
        }
        return -1;
    }
}