45 lines
1.2 KiB
Java
45 lines
1.2 KiB
Java
package com.muyu.utils;
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/**
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* 校验位计算
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*/
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public class CalculateCheckDigit {
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/**
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* 不去空格
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* @param sHex
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* @return
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*/
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public static String makeCheck(String sHex){
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return makeCheckSum(sHex.replace(" ", ""));
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}
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/**
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* 计算校验位 ，返回十六进制校验位
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* */
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private static String makeCheckSum(String data) {
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int dSum = 0;
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int length = data.length();
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int index = 0;
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// 遍历十六进制，并计算总和
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while (index < length) {
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// 截取2位字符
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String s = data.substring(index, index + 2);
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// 十六进制转成十进制 , 并计算十进制的总和
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dSum += Integer.parseInt(s, 16);
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index = index + 2;
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}
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// 用256取余，十六进制最大是FF，FF的十进制是255
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int mod = dSum % 256;
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// 余数转成十六进制
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String checkSumHex = Integer.toHexString(mod);
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length = checkSumHex.length();
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if (length < 2) {
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// 校验位不足两位的，在前面补0
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checkSumHex = "0" + checkSumHex;
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}
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return checkSumHex;
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}
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}
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