Here you can find the source of calculateCRC32(byte[] buf, int off, int len)
| Parameter | Description |
|---|---|
| buf | the byte array to calculate CRC32 on |
| off | the offset within buf at which the CRC32 calculation will start |
| len | the number of bytes on which to calculate the CRC32 |
static public int calculateCRC32(byte[] buf, int off, int len)
//package com.java2s; /*//from w w w . j a v a2s.c om * (c) copyright 2003-2007 Amichai Rothman * * This file is part of the Java TNEF package. * * The Java TNEF package is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * The Java TNEF package is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ public class Main { /** The lookup table used in the CRC32 calculation */ static int[] CRC32_TABLE; /** * Calculates the CRC32 of the given bytes. The CRC32 calculation is similar * to the standard one as demonstrated in RFC 1952, but with the inversion * (before and after the calculation) ommited. * * @param buf * the byte array to calculate CRC32 on * @param off * the offset within buf at which the CRC32 calculation will * start * @param len * the number of bytes on which to calculate the CRC32 * @return the CRC32 value. */ static public int calculateCRC32(byte[] buf, int off, int len) { int c = 0; int end = off + len; for (int i = off; i < end; i++) { c = CRC32_TABLE[(c ^ buf[i]) & 0xFF] ^ (c >>> 8); } return c; } }