Java crc32算法

朱雀 2023-07-17 02:49 166阅读 0赞

package com.goldpac.ocs.operation.util;
    
    /**
     * CRC-32
     *
     * <table width="400px" border="1" cellpadding="0" cellspacing="0">
     *     <tr>
     *         <th>名称</th>
     *         <th>多项式</th>
     *         <th>初始值</th>
     *         <th>异或值</th>
     *         <th>Bit反转</th>
     *     </tr>
     *     <tr>
     *         <td>  CRC-32</td>
     *         <td align="center">0x04C11DB7</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">LSB First</td>
     *     </tr>
     *     <tr>
     *         <td>  CRC-32/B</td>
     *         <td align="center">0x04C11DB7</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">MSB First</td>
     *     </tr>
     *     <tr>
     *         <td>  CRC-32/C</td>
     *         <td align="center">0x1EDC6F41</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">LSB First</td>
     *     </tr>
     *     <tr>
     *         <td>  CRC-32/D</td>
     *         <td align="center">0xA833982B</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">LSB First</td>
     *     </tr>
     *     <tr>
     *         <td>  CRC-32/MPEG-2</td>
     *         <td align="center">0x04C11DB7</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">0x00000000</td>
     *         <td align="center">MSB First</td>
     *     </tr>
     *     <tr>
     *         <td>  CRC-32/POSIX</td>
     *         <td align="center">0x04C11DB7</td>
     *         <td align="center">0x00000000</td>
     *         <td align="center">0xFFFFFFFF</td>
     *         <td align="center">MSB First</td>
     *     </tr>
     * </table>
     *
     * @author unnamed
     *
     */
    public class CRC32Utils {
    
        /**
         * CRC-32
         *
         * <table width="400px" border="1" cellpadding="0" cellspacing="0">
         *     <tr>
         *         <th>多项式</th>
         *         <th>初始值</th>
         *         <th>异或值</th>
         *         <th>Bit反转</th>
         *     </tr>
         *     <tr>
         *         <td align="center">0x04C11DB7</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">LSB First</td>
         *     </tr>
         * </table>
         *
         * @param  source
         * @param  offset
         * @param  length
         * @return
         */
        public static long CRC32(byte[] source, int offset, int length) {
            long wCRCin = 0xFFFFFFFFL;
            // Long.reverse(0x04C11DB7L) >>> 32
            long wCPoly = 0xEDB88320L;
            for (int i = offset, cnt = offset + length; i < cnt; i++) {
                wCRCin ^= ((long) source[i] & 0x000000FFL);
                for (int j = 0; j < 8; j++) {
                    if ((wCRCin & 0x00000001L) != 0) {
                        wCRCin >>= 1;
                        wCRCin ^= wCPoly;
                    } else {
                        wCRCin >>= 1;
                    }
                }
            }
            return wCRCin ^= 0xFFFFFFFFL;
        }
    
        /**
         * CRC-32/B
         *
         * <table width="400px" border="1" cellpadding="0" cellspacing="0">
         *     <tr>
         *         <th>多项式</th>
         *         <th>初始值</th>
         *         <th>异或值</th>
         *         <th>Bit反转</th>
         *     </tr>
         *     <tr>
         *         <td align="center">0x04C11DB7</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">MSB First</td>
         *     </tr>
         * </table>
         *
         * @param  source
         * @param  offset
         * @param  length
         * @return
         */
        public static long CRC32_B(byte[] source, int offset, int length) {
            long wCRCin = 0xFFFFFFFFL;
            long wCPoly = 0x04C11DB7L;
            for (int i = offset, cnt = offset + length; i < cnt; i++) {
                for (int j = 0; j < 8; j++) {
                    boolean bit = ((source[i] >> (7 - j) & 1) == 1);
                    boolean c31 = ((wCRCin >> 31 & 1) == 1);
                    wCRCin <<= 1;
                    if (c31 ^ bit) {
                        wCRCin ^= wCPoly;
                    }
                }
            }
            wCRCin &= 0xFFFFFFFFL;
            return wCRCin ^= 0xFFFFFFFFL;
        }
    
        /**
         * CRC-32/C
         *
         * <table width="400px" border="1" cellpadding="0" cellspacing="0">
         *     <tr>
         *         <th>多项式</th>
         *         <th>初始值</th>
         *         <th>异或值</th>
         *         <th>Bit反转</th>
         *     </tr>
         *     <tr>
         *         <td align="center">0x1EDC6F41</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">LSB First</td>
         *     </tr>
         * </table>
         *
         * @param  source
         * @param  offset
         * @param  length
         * @return
         */
        public static long CRC32_C(byte[] source, int offset, int length) {
            long wCRCin = 0xFFFFFFFFL;
            // Long.reverse(0x1EDC6F41L) >>> 32
            long wCPoly = 0x82F63B78L;
            for (int i = offset, cnt = offset + length; i < cnt; i++) {
                wCRCin ^= ((long) source[i] & 0x000000FFL);
                for (int j = 0; j < 8; j++) {
                    if ((wCRCin & 0x00000001L) != 0) {
                        wCRCin >>= 1;
                        wCRCin ^= wCPoly;
                    } else {
                        wCRCin >>= 1;
                    }
                }
            }
            return wCRCin ^= 0xFFFFFFFFL;
        }
    
        /**
         * CRC-32/D
         *
         * <table width="400px" border="1" cellpadding="0" cellspacing="0">
         *     <tr>
         *         <th>多项式</th>
         *         <th>初始值</th>
         *         <th>异或值</th>
         *         <th>Bit反转</th>
         *     </tr>
         *     <tr>
         *         <td align="center">0xA833982B</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">LSB First</td>
         *     </tr>
         * </table>
         *
         * @param  source
         * @param  offset
         * @param  length
         * @return
         */
        public static long CRC32_D(byte[] source, int offset, int length) {
            long wCRCin = 0xFFFFFFFFL;
            // Long.reverse(0xA833982BL) >>> 32
            long wCPoly = 0xD419CC15L;
            for (int i = offset, cnt = offset + length; i < cnt; i++) {
                wCRCin ^= ((long) source[i] & 0x000000FFL);
                for (int j = 0; j < 8; j++) {
                    if ((wCRCin & 0x00000001L) != 0) {
                        wCRCin >>= 1;
                        wCRCin ^= wCPoly;
                    } else {
                        wCRCin >>= 1;
                    }
                }
            }
            return wCRCin ^= 0xFFFFFFFFL;
        }
    
        /**
         * CRC-32/MPEG-2
         *
         * <table width="400px" border="1" cellpadding="0" cellspacing="0">
         *     <tr>
         *         <th>多项式</th>
         *         <th>初始值</th>
         *         <th>异或值</th>
         *         <th>Bit反转</th>
         *     </tr>
         *     <tr>
         *         <td align="center">0x04C11DB7</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">0x00000000</td>
         *         <td align="center">MSB First</td>
         *     </tr>
         * </table>
         *
         * @param  source
         * @param  offset
         * @param  length
         * @return
         */
        public static long CRC32_MPEG_2(byte[] source, int offset, int length) {
            long wCRCin = 0xFFFFFFFFL;
            long wCPoly = 0x04C11DB7L;
            for (int i = offset, cnt = offset + length; i < cnt; i++) {
                for (int j = 0; j < 8; j++) {
                    boolean bit = ((source[i] >> (7 - j) & 1) == 1);
                    boolean c31 = ((wCRCin >> 31 & 1) == 1);
                    wCRCin <<= 1;
                    if (c31 ^ bit) {
                        wCRCin ^= wCPoly;
                    }
                }
            }
            wCRCin &= 0xFFFFFFFFL;
            return wCRCin ^= 0x00000000L;
        }
    
        /**
         * CRC-32/POSIX
         *
         * <table width="400px" border="1" cellpadding="0" cellspacing="0">
         *     <tr>
         *         <th>多项式</th>
         *         <th>初始值</th>
         *         <th>异或值</th>
         *         <th>Bit反转</th>
         *     </tr>
         *     <tr>
         *         <td align="center">0x04C11DB7</td>
         *         <td align="center">0x00000000</td>
         *         <td align="center">0xFFFFFFFF</td>
         *         <td align="center">MSB First</td>
         *     </tr>
         * </table>
         *
         * @param  source
         * @param  offset
         * @param  length
         * @return
         */
        public static long CRC32_POSIX(byte[] source, int offset, int length) {
            long wCRCin = 0x00000000L;
            long wCPoly = 0x04C11DB7L;
            for (int i = offset, cnt = offset + length; i < cnt; i++) {
                for (int j = 0; j < 8; j++) {
                    boolean bit = ((source[i] >> (7 - j) & 1) == 1);
                    boolean c31 = ((wCRCin >> 31 & 1) == 1);
                    wCRCin <<= 1;
                    if (c31 ^ bit) {
                        wCRCin ^= wCPoly;
                    }
                }
            }
            wCRCin &= 0xFFFFFFFFL;
            return wCRCin ^= 0xFFFFFFFFL;
        }
    
    }

其实这个可以直接用

import java.util.zip.CRC32;
    
    CRC32 crc = new CRC32();

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0NTIxNDMx_size_16_color_FFFFFF_t_70][]

效果一样

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