001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.component.file.strategy;
018
019 import java.io.File;
020 import java.io.RandomAccessFile;
021 import java.nio.channels.Channel;
022 import java.nio.channels.FileChannel;
023 import java.nio.channels.FileLock;
024
025 import org.apache.camel.component.file.FileEndpoint;
026 import org.apache.camel.component.file.FileExchange;
027 import org.apache.camel.component.file.FileProcessStrategy;
028 import org.apache.camel.util.ExchangeHelper;
029 import org.apache.camel.util.ObjectHelper;
030 import org.apache.commons.logging.Log;
031 import org.apache.commons.logging.LogFactory;
032
033 /**
034 * Base class for {@link org.apache.camel.component.file.FileProcessStrategy} implementation to extend.
035 *
036 * @version $Revision: 697472 $
037 */
038 public abstract class FileProcessStrategySupport implements FileProcessStrategy {
039 private static final transient Log LOG = LogFactory.getLog(FileProcessStrategySupport.class);
040 private boolean lockFile;
041 private FileRenamer lockFileRenamer;
042
043 protected FileProcessStrategySupport() {
044 this(true);
045 }
046
047 protected FileProcessStrategySupport(boolean lockFile) {
048 this(lockFile, new DefaultFileRenamer(null, FileEndpoint.DEFAULT_LOCK_FILE_POSTFIX));
049 }
050
051 protected FileProcessStrategySupport(boolean lockFile, FileRenamer lockFileRenamer) {
052 this.lockFile = lockFile;
053 this.lockFileRenamer = lockFileRenamer;
054 }
055
056 public boolean begin(FileEndpoint endpoint, FileExchange exchange, File file) throws Exception {
057 if (isLockFile()) {
058 File newFile = lockFileRenamer.renameFile(exchange, file);
059 String lockFileName = newFile.getAbsolutePath();
060 if (LOG.isDebugEnabled()) {
061 LOG.debug("Locking the file: " + file + " using the lock file name: " + lockFileName);
062 }
063
064 FileChannel channel = new RandomAccessFile(lockFileName, "rw").getChannel();
065 FileLock lock = channel.lock();
066 if (lock != null) {
067 exchange.setProperty("org.apache.camel.file.lock", lock);
068 exchange.setProperty("org.apache.camel.file.lock.name", lockFileName);
069 return true;
070 } else {
071 return false;
072 }
073 }
074 return true;
075 }
076
077 public void commit(FileEndpoint endpoint, FileExchange exchange, File file) throws Exception {
078 unlockFile(endpoint, exchange, file);
079 }
080
081 public void rollback(FileEndpoint endpoint, FileExchange exchange, File file) {
082 try {
083 unlockFile(endpoint, exchange, file);
084 } catch (Exception e) {
085 LOG.warn("Unable to unlock file: " + file, e);
086 }
087 }
088
089 public boolean isLockFile() {
090 return lockFile;
091 }
092
093 public void setLockFile(boolean lockFile) {
094 this.lockFile = lockFile;
095 }
096
097 public FileRenamer getLockFileRenamer() {
098 return lockFileRenamer;
099 }
100
101 public void setLockFileRenamer(FileRenamer lockFileRenamer) {
102 this.lockFileRenamer = lockFileRenamer;
103 }
104
105 protected void unlockFile(FileEndpoint endpoint, FileExchange exchange, File file) throws Exception {
106 if (isLockFile()) {
107 FileLock lock = ExchangeHelper.getMandatoryProperty(exchange, "org.apache.camel.file.lock", FileLock.class);
108 String lockFileName = ExchangeHelper.getMandatoryProperty(exchange, "org.apache.camel.file.lock.name", String.class);
109 Channel channel = lock.channel();
110 if (LOG.isDebugEnabled()) {
111 LOG.debug("Unlocking file: " + file);
112 }
113 try {
114 lock.release();
115 } finally {
116 // must close channel
117 ObjectHelper.close(channel, "Closing channel", LOG);
118
119 if (LOG.isTraceEnabled()) {
120 LOG.trace("Deleting lock file: " + lockFileName);
121 }
122 File lockfile = new File(lockFileName);
123 lockfile.delete();
124 }
125 }
126 }
127 }