中国贸易网站,电子商务seo优化,手机制作,南浔网站建设CRC即循环冗余校验码#xff08;Cyclic Redundancy Check#xff09;#xff1a;是数据通信领域中最常用的一种差错校验码#xff0c;其特征是信息字段和校验字段的长度可以任意选定。 1 byte checksum CRC-16 CRC-16 (Modbus) CRC-16 (Sick) … CRC即循环冗余校验码Cyclic Redundancy Check是数据通信领域中最常用的一种差错校验码其特征是信息字段和校验字段的长度可以任意选定。 1 byte checksum CRC-16 CRC-16 (Modbus) CRC-16 (Sick) CRC-CCITT (XModem) CRC-CCITT (0xFFFF) CRC-CCITT (0x1D0F) CRC-CCITT (Kermit) CRC-DNP CRC-32 这里我以CRC-CCITT (XModem) 为例分别用计算方法与查表法来实现 1.计算法 public static int CRC_XModem(byte[] bytes){int crc 0x00; // initial valueint polynomial 0x1021; for (int index 0 ; index bytes.length; index) {byte b bytes[index];for (int i 0; i 8; i) {boolean bit ((b (7-i) 1) 1);boolean c15 ((crc 15 1) 1);crc 1;if (c15 ^ bit) crc ^ polynomial;}}crc 0xffff;return crc; } 2.查表法 static final char TABLE1021[] { /* CRC1021余式表 */ 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 }; public static char getCRC1021(byte b[], int len) { char crc 0; byte hb 0; int j 0; int index; while (len-- ! 0) { hb (byte) (crc / 256); //以8位二进制数的形式暂存CRC的高8位 index ((hb ^ b[j]) 0xff); //求得所查索引下标 crc 8; // 左移8位相当于CRC的低8位乘以 crc ^ (TABLE1021[index]); // 高8位和当前字节相加后再查表求CRC 再加上以前的CRC j; } return (crc); } 3.测试方法与结果 public static void main(String args[]) {byte[] b new byte[] {(byte) 0x2C, (byte) 0x00, (byte) 0xFF, (byte) 0xFE,(byte) 0xFE, (byte) 0x04, (byte) 0x00, (byte) 0x00,(byte) 0x00, (byte) 0x00 };int a getCRC1021(b, 10);System.out.println(查表法: a);String str Integer.toHexString(a).toUpperCase();System.out.println(十六进制: str);System.out.println(计算法: CRC_XModem(b));System.out.println(十六进制: Integer.toHexString(CRC_XModem(b)).toUpperCase());} 结果 转载于:https://www.cnblogs.com/snake-hand/p/3143034.html
