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
021 import org.apache.camel.Exchange;
022 import org.apache.camel.component.file.FileComponent;
023 import org.apache.camel.component.file.GenericFile;
024 import org.apache.camel.component.file.GenericFileEndpoint;
025 import org.apache.camel.component.file.GenericFileExclusiveReadLockStrategy;
026 import org.apache.camel.component.file.GenericFileOperations;
027 import org.apache.camel.util.ExchangeHelper;
028 import org.apache.camel.util.FileUtil;
029 import org.apache.commons.logging.Log;
030 import org.apache.commons.logging.LogFactory;
031
032 /**
033 * Acquires read lock to the given file using a marker file so other Camel consumers wont acquire the same file.
034 * This is the default behavior in Camel 1.x.
035 */
036 public class MarkerFileExclusiveReadLockStrategy implements GenericFileExclusiveReadLockStrategy<File> {
037 private static final transient Log LOG = LogFactory.getLog(MarkerFileExclusiveReadLockStrategy.class);
038
039 public void prepareOnStartup(GenericFileOperations<File> operations, GenericFileEndpoint<File> endpoint) {
040 String dir = endpoint.getConfiguration().getDirectory();
041 File file = new File(dir);
042
043 if (LOG.isDebugEnabled()) {
044 LOG.debug("Prepare on startup by deleting orphaned lock files from: " + dir);
045 }
046
047 deleteLockFiles(file, endpoint.isRecursive());
048 }
049
050 @SuppressWarnings("unchecked")
051 public boolean acquireExclusiveReadLock(GenericFileOperations<File> operations,
052 GenericFile<File> file, Exchange exchange) throws Exception {
053
054 String lockFileName = file.getAbsoluteFilePath() + FileComponent.DEFAULT_LOCK_FILE_POSTFIX;
055 if (LOG.isTraceEnabled()) {
056 LOG.trace("Locking the file: " + file + " using the lock file name: " + lockFileName);
057 }
058
059 // create a plain file as marker filer for locking (do not use FileLock)
060 File lock = new File(lockFileName);
061 boolean acquired = lock.createNewFile();
062 if (acquired) {
063 exchange.setProperty("CamelFileLock", lock);
064 exchange.setProperty("CamelFileLockName", lockFileName);
065 }
066
067 return acquired;
068 }
069
070 public void releaseExclusiveReadLock(GenericFileOperations<File> operations,
071 GenericFile<File> file, Exchange exchange) throws Exception {
072
073 File lock = ExchangeHelper.getMandatoryProperty(exchange, "CamelFileLock", File.class);
074 String lockFileName = ExchangeHelper.getMandatoryProperty(exchange, "CamelFileLockName", String.class);
075
076 if (LOG.isTraceEnabled()) {
077 LOG.trace("Unlocking file: " + lockFileName);
078 }
079
080 boolean deleted = FileUtil.deleteFile(lock);
081 if (LOG.isTraceEnabled()) {
082 LOG.trace("Lock file: " + lockFileName + " was deleted: " + deleted);
083 }
084 }
085
086 public void setTimeout(long timeout) {
087 // noop
088 }
089
090 private static void deleteLockFiles(File dir, boolean recursive) {
091 File[] files = dir.listFiles();
092 if (files == null || files.length == 0) {
093 return;
094 }
095
096 for (File file : files) {
097 if (file.getName().startsWith(".")) {
098 // files starting with dot should be skipped
099 continue;
100 } else if (file.getName().endsWith(FileComponent.DEFAULT_LOCK_FILE_POSTFIX)) {
101 LOG.warn("Deleting orphaned lock file: " + file);
102 FileUtil.deleteFile(file);
103 } else if (recursive && file.isDirectory()) {
104 deleteLockFiles(file, true);
105 }
106 }
107 }
108
109 }