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.GenericFile; 023 import org.apache.camel.component.file.GenericFileOperations; 024 025 /** 026 * Acquires exclusive read lock to the given file. Will wait until the lock is granted. 027 * After granting the read lock it is released, we just want to make sure that when we start 028 * consuming the file its not currently in progress of being written by third party. 029 * <p/> 030 * This implementation is only supported by the File component, that leverages the {@link MarkerFileExclusiveReadLockStrategy} 031 * as well, to ensure only acquiring locks on files, which is not already in progress by another process, 032 * that have marked this using the marker file. 033 */ 034 public class FileRenameExclusiveReadLockStrategy extends GenericFileRenameExclusiveReadLockStrategy<File> { 035 036 private MarkerFileExclusiveReadLockStrategy marker = new MarkerFileExclusiveReadLockStrategy(); 037 038 @Override 039 public boolean acquireExclusiveReadLock(GenericFileOperations<File> operations, GenericFile<File> file, Exchange exchange) throws Exception { 040 // must call marker first 041 if (!marker.acquireExclusiveReadLock(operations, file, exchange)) { 042 return false; 043 } 044 045 return super.acquireExclusiveReadLock(operations, file, exchange); 046 } 047 048 @Override 049 public void releaseExclusiveReadLock(GenericFileOperations<File> operations, 050 GenericFile<File> file, Exchange exchange) throws Exception { 051 // must call marker first 052 try { 053 marker.releaseExclusiveReadLock(operations, file, exchange); 054 } finally { 055 super.releaseExclusiveReadLock(operations, file, exchange); 056 } 057 } 058 059 }