CRC 校验

原帖子地址：http://cuisuqiang.iteye.com/blog/1716654

CRC 校验

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• 网络编程

崔素强cuisuqiangcrcjava校验

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。

Java代码

1. import java.util.Arrays; 
2.  
3. /**
4. * @说明 CRC校验类
5. * @author cuisuqiang
6. * @version 1.0
7. * @since
8. */ 
9. public class CRCCheck { 
10.      
11.     public staticvoid main(String[] args) { 
12.         byte[] btm = newbyte[] { 12,13, 1,0, 0,1, 0,31, -19,0, 8, 
13.                 0, 1 }; 
14.         byte[] btl = CRCCheck.getCRCByteValue(btm); 
15.         System.out.println(Arrays.toString(btl)); 
16.     } 
17.  
18.     /**
19.      * 入口方法
20.      * @param bt 需要校验的字节流
21.      * @return
22.      */ 
23.     public staticbyte[] getCRCByteValue(byte[] bt){ 
24.         char ch = caluCRC(bt); 
25.         return charToByte(ch); 
26.     } 
27.  
28.     public staticchar[] crc_tb = { 0x0000,0x1021, 0x2042,0x3063, 0x4084, 
29.             0x50a5, 0x60c6,0x70e7, 0x8108,0x9129, 0xa14a,0xb16b, 0xc18c, 
30.             0xd1ad, 0xe1ce,0xf1ef, 0x1231,0x0210, 0x3273,0x2252, 0x52b5, 
31.             0x4294, 0x72f7,0x62d6, 0x9339,0x8318, 0xb37b,0xa35a, 0xd3bd, 
32.             0xc39c, 0xf3ff,0xe3de, 0x2462,0x3443, 0x0420,0x1401, 0x64e6, 
33.             0x74c7, 0x44a4,0x5485, 0xa56a,0xb54b, 0x8528,0x9509, 0xe5ee, 
34.             0xf5cf, 0xc5ac,0xd58d, 0x3653,0x2672, 0x1611,0x0630, 0x76d7, 
35.             0x66f6, 0x5695,0x46b4, 0xb75b,0xa77a, 0x9719,0x8738, 0xf7df, 
36.             0xe7fe, 0xd79d,0xc7bc, 0x48c4,0x58e5, 0x6886,0x78a7, 0x0840, 
37.             0x1861, 0x2802,0x3823, 0xc9cc,0xd9ed, 0xe98e,0xf9af, 0x8948, 
38.             0x9969, 0xa90a,0xb92b, 0x5af5,0x4ad4, 0x7ab7,0x6a96, 0x1a71, 
39.             0x0a50, 0x3a33,0x2a12, 0xdbfd,0xcbdc, 0xfbbf,0xeb9e, 0x9b79, 
40.             0x8b58, 0xbb3b,0xab1a, 0x6ca6,0x7c87, 0x4ce4,0x5cc5, 0x2c22, 
41.             0x3c03, 0x0c60,0x1c41, 0xedae,0xfd8f, 0xcdec,0xddcd, 0xad2a, 
42.             0xbd0b, 0x8d68,0x9d49, 0x7e97,0x6eb6, 0x5ed5,0x4ef4, 0x3e13, 
43.             0x2e32, 0x1e51,0x0e70, 0xff9f,0xefbe, 0xdfdd,0xcffc, 0xbf1b, 
44.             0xaf3a, 0x9f59,0x8f78, 0x9188,0x81a9, 0xb1ca,0xa1eb, 0xd10c, 
45.             0xc12d, 0xf14e,0xe16f, 0x1080,0x00a1, 0x30c2,0x20e3, 0x5004, 
46.             0x4025, 0x7046,0x6067, 0x83b9,0x9398, 0xa3fb,0xb3da, 0xc33d, 
47.             0xd31c, 0xe37f,0xf35e, 0x02b1,0x1290, 0x22f3,0x32d2, 0x4235, 
48.             0x5214, 0x6277,0x7256, 0xb5ea,0xa5cb, 0x95a8,0x8589, 0xf56e, 
49.             0xe54f, 0xd52c,0xc50d, 0x34e2,0x24c3, 0x14a0,0x0481, 0x7466, 
50.             0x6447, 0x5424,0x4405, 0xa7db,0xb7fa, 0x8799,0x97b8, 0xe75f, 
51.             0xf77e, 0xc71d,0xd73c, 0x26d3,0x36f2, 0x0691,0x16b0, 0x6657, 
52.             0x7676, 0x4615,0x5634, 0xd94c,0xc96d, 0xf90e,0xe92f, 0x99c8, 
53.             0x89e9, 0xb98a,0xa9ab, 0x5844,0x4865, 0x7806,0x6827, 0x18c0, 
54.             0x08e1, 0x3882,0x28a3, 0xcb7d,0xdb5c, 0xeb3f,0xfb1e, 0x8bf9, 
55.             0x9bd8, 0xabbb,0xbb9a, 0x4a75,0x5a54, 0x6a37,0x7a16, 0x0af1, 
56.             0x1ad0, 0x2ab3,0x3a92, 0xfd2e,0xed0f, 0xdd6c,0xcd4d, 0xbdaa, 
57.             0xad8b, 0x9de8,0x8dc9, 0x7c26,0x6c07, 0x5c64,0x4c45, 0x3ca2, 
58.             0x2c83, 0x1ce0,0x0cc1, 0xef1f,0xff3e, 0xcf5d,0xdf7c, 0xaf9b, 
59.             0xbfba, 0x8fd9,0x9ff8, 0x6e17,0x7e36, 0x4e55,0x5e74, 0x2e93, 
60.             0x3eb2, 0x0ed1,0x1ef0 }; 
61.  
62.     /**
63.      * 获得CRC验证码
64.      */ 
65.     public staticchar caluCRC(byte[] pByte) { 
66.         int len = pByte.length; 
67.         char crc; 
68.         byte da; 
69.         crc = 0x0; 
70.         int i = 0; 
71.         while (len-- != 0) { 
72.             da = (byte) (crc / 256); 
73.             crc <<= 8; 
74.             int num = da ^ pByte[i]; 
75.             if (num < 0) 
76.                 num += 256; 
77.             crc ^= crc_tb[num]; 
78.             ++i; 
79.         } 
80.         return crc; 
81.     } 
82.  
83.     /**
84.      * char 转byte
85.      */ 
86.     public staticbyte[] charToByte(char c) { 
87.         byte[] b = newbyte[2]; 
88.         b[0] = (byte) ((c &0xFF00) >> 8); 
89.         b[1] = (byte) (c &0xFF); 
90.         return b; 
91.     } 
92.      
93. }