Java tutorial
package io.blobkeeper.file.domain; /* * Copyright (C) 2015 by Denis M. Gabaydulin * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ import com.google.common.collect.ComparisonChain; import io.blobkeeper.common.util.AlphaNumComparator; import org.apache.commons.io.FilenameUtils; import org.jetbrains.annotations.NotNull; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; import java.nio.channels.FileChannel; import static com.google.common.base.MoreObjects.toStringHelper; import static com.google.common.collect.Ordering.from; public class File implements Comparable<File> { private static final Logger log = LoggerFactory.getLogger(File.class); private final RandomAccessFile accessFile; private final String name; private final FileChannel channel; public File(java.io.File absolutePath) { name = FilenameUtils.getName(absolutePath.getAbsolutePath()); try { accessFile = new RandomAccessFile(absolutePath, "rw"); accessFile.seek(0); this.channel = accessFile.getChannel(); } catch (FileNotFoundException e) { log.error("Can't open file", e); throw new IllegalArgumentException(e); } catch (IOException e) { log.error("Can't seek file", e); throw new IllegalArgumentException(e); } } public void preallocate(long fileSize) { try { accessFile.setLength(fileSize); } catch (IOException e) { log.error("Can't preallocate file", e); throw new IllegalArgumentException(e); } } public void close() { try { accessFile.close(); } catch (IOException e) { log.error("Can't close file", e); throw new IllegalArgumentException(e); } } public FileChannel getFileChannel() { return channel; } public String getName() { return name; } public long getLength() { try { return channel.size(); } catch (IOException e) { log.error("Can't get length of the file", e); throw new IllegalStateException(e); } } @Override public String toString() { return toStringHelper(this).addValue(name).toString(); } @Override public int compareTo(@NotNull File other) { return ComparisonChain.start().compare(this.name, other.getName(), from(new AlphaNumComparator())).result(); } }