/* * Copyright 2010 Srikanth Reddy Lingala * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package net.lingala.zip4j.util; import net.lingala.zip4j.exception.ZipException; import net.lingala.zip4j.progress.ProgressMonitor; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.util.zip.CRC32; public class CrcUtil { private static final int BUF_SIZE = 1 << 14; //16384 public static long computeFileCrc(File inputFile, ProgressMonitor progressMonitor) throws IOException { if (inputFile == null || !inputFile.exists() || !inputFile.canRead()) { throw new ZipException("input file is null or does not exist or cannot read. " + "Cannot calculate CRC for the file"); } byte[] buff = new byte[BUF_SIZE]; CRC32 crc32 = new CRC32(); try(InputStream inputStream = new FileInputStream(inputFile)) { int readLen; while ((readLen = inputStream.read(buff)) != -1) { crc32.update(buff, 0, readLen); if (progressMonitor != null) { progressMonitor.updateWorkCompleted(readLen); if (progressMonitor.isCancelAllTasks()) { progressMonitor.setResult(ProgressMonitor.Result.CANCELLED); progressMonitor.setState(ProgressMonitor.State.READY); return 0; } } } return crc32.getValue(); } } }