Java tutorial
/* * ------------------------------------------------------------------------------ * Hermes FTP Server * Copyright (c) 2005-2014 Lars Behnke * ------------------------------------------------------------------------------ * * This file is part of Hermes FTP Server. * * Hermes FTP Server 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. * * Hermes FTP Server 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 Hermes FTP Server; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * ------------------------------------------------------------------------------ */ package com.apporiented.hermesftp.streams; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.File; import java.io.IOException; import java.io.OutputStream; import java.io.RandomAccessFile; /** * Wrapper class for writing to a RandomAccessFile through the OutputStream abstraction. * * @author Lars Behnke */ public class RafOutputStream extends OutputStream implements RecordWriteSupport { private static Log log = LogFactory.getLog(RafOutputStream.class); private RandomAccessFile raf; private File file; private long offset; /** * Constructor. * * @param file The output file; */ public RafOutputStream(File file) { super(); this.file = file; this.offset = 0; } /** * Constructor. * * @param file The output file; * @param offset The number of bytes to be skipped, when writing to the file. */ public RafOutputStream(File file, long offset) { super(); this.file = file; this.offset = offset; } /** * Constructor. * * @param file The output file; * @param append Indication whether the data is to be appended to the output file. */ public RafOutputStream(File file, boolean append) { super(); this.file = file; this.offset = -1; } /** * {@inheritDoc} */ public void write(int b) throws IOException { getRaf().write(b); } /** * {@inheritDoc} */ public void write(byte[] b) throws IOException { getRaf().write(b); } /** * {@inheritDoc} */ public void write(byte[] b, int off, int len) throws IOException { getRaf().write(b, off, len); } /** * {@inheritDoc} */ public void writeRecord(byte[] data, boolean eof) throws IOException { write(data); String lineSep = System.getProperty("line.separator"); write(lineSep.getBytes()); } /** * {@inheritDoc} */ public void close() throws IOException { getRaf().close(); } private RandomAccessFile getRaf() throws IOException { if (raf == null) { raf = new RandomAccessFile(file, "rw"); if (offset > 0) { raf.seek(offset); } else if (offset < 0) { raf.seek(raf.length()); } } return raf; } }