Java tutorial
/************************************************************************* * Copyright 2009-2014 Eucalyptus Systems, Inc. * * This program 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; version 3 of the License. * * This program 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, see http://www.gnu.org/licenses/. * * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need * additional information or have any questions. * * This file may incorporate work covered under the following copyright * and permission notice: * * Software License Agreement (BSD License) * * Copyright (c) 2008, Regents of the University of California * All rights reserved. * * Redistribution and use of this software in source and binary forms, * with or without modification, are permitted provided that the * following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. USERS OF THIS SOFTWARE ACKNOWLEDGE * THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE LICENSED MATERIAL, * COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS SOFTWARE, * AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING * IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, * SANTA BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, * WHICH IN THE REGENTS' DISCRETION MAY INCLUDE, WITHOUT LIMITATION, * REPLACEMENT OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO * IDENTIFIED, OR WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT * NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS. ************************************************************************/ package com.eucalyptus.blockstorage; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import com.eucalyptus.blockstorage.exceptions.UnknownSizeException; import com.eucalyptus.blockstorage.util.StorageProperties; import edu.ucsb.eucalyptus.util.SystemUtil; import edu.ucsb.eucalyptus.util.SystemUtil.CommandOutput; public class BlockDeviceResource extends StorageResource { private static final int ATTEMPTS = 10; private static Logger LOG = Logger.getLogger(BlockDeviceResource.class); public BlockDeviceResource(String id, String name) { super(id, name, StorageResource.Type.BLOCK); } @Override public Long getSize() throws UnknownSizeException { Long size = 0L; try { CommandOutput result = SystemUtil.runWithRawOutput(new String[] { StorageProperties.EUCA_ROOT_WRAPPER, "blockdev", "--getsize64", this.getPath() }); size = Long.parseLong(StringUtils.trimToEmpty(result.output)); return size; } catch (Exception e) { throw new UnknownSizeException( "Failed to determine size for " + this.getId() + " mounted at " + this.getPath(), e); } } @Override public InputStream getInputStream() throws FileNotFoundException { return new FileInputStream(new File(this.getPath())); } @Override public OutputStream getOutputStream() throws IOException { FileOutputStream outStream = null; int failedAttempts = 0; do { try { outStream = new FileOutputStream(new File(this.getPath())); return outStream; } catch (FileNotFoundException e) { // Output stream to block devices may throw permission denied error, retry a few times if ((++failedAttempts) < ATTEMPTS) { LOG.debug("Failed to open FileOutputStream for " + this.getId() + " mounted at " + this.getPath() + ". Will retry"); } else { LOG.warn("Failed to open FileOutputStream for " + this.getId() + " mounted at " + this.getPath() + " after " + failedAttempts + " attempts"); throw e; } } } while (failedAttempts < ATTEMPTS); throw new IOException( "Failed to open FileOutputStream for " + this.getId() + " mounted at " + this.getPath()); } @Override public Boolean isDownloadSynchronous() { return Boolean.TRUE; } }