java累加和校验实现方式16进制(推荐)

public static String makeChecksum(String data) { if (data == null || data.equals("")) {  return ""; } int total = 0; int len = data.length(); int num = 0; while (num < len) {  String s = data.substring(num, num + 2);  System.out.println(s);  total += Integer.parseInt(s, 16);  num = num + 2; } /**  * 用256求余最大是255，即16进制的FF  */ int mod = total % 256; String hex = Integer.toHexString(mod); len = hex.length(); // 如果不够校验位的长度，补0,这里用的是两位校验 if (len < 2) {  hex = "0" + hex; } return hex; }