Java不使用系统方法实现十进制转十六进制

注意：该代码仅仅是整数之间的转换
public class Test {
    public static void main(String[] args) {
        Scanner sin = new Scanner(System.in);
        int index = sin.nextInt();

        String res = "";
        if (index == 0) {
            System.out.println(0);
        } else if (index > 0){
            res = getRes(index);
        } else {
            index = -index;
            res = "-" + getRes(index);
        }
        System.out.println(res);
    }

    public static String getRes(int index) {
        String res = "";
        while (index != 0) {
            int t = index % 16;
            if (t >= 10) {
                res = (char)(t - 10 + 'A') + res;
            } else {
                res = t + res;
            }
            index = index / 16;
        }
        return res;
    }
}