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 */ 017package org.apache.camel.component.file.strategy; 018 019import java.io.File; 020 021import org.apache.camel.Exchange; 022import org.apache.camel.component.file.GenericFile; 023import 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 * <p/> 034 * Setting the option {@link #setMarkerFiler(boolean)} to <tt>false</tt> allows to turn off using marker files. 035 */ 036public class FileRenameExclusiveReadLockStrategy extends GenericFileRenameExclusiveReadLockStrategy<File> { 037 038 private MarkerFileExclusiveReadLockStrategy marker = new MarkerFileExclusiveReadLockStrategy(); 039 private boolean markerFile = true; 040 041 @Override 042 public boolean acquireExclusiveReadLock(GenericFileOperations<File> operations, GenericFile<File> file, Exchange exchange) throws Exception { 043 // must call marker first 044 if (markerFile && !marker.acquireExclusiveReadLock(operations, file, exchange)) { 045 return false; 046 } 047 048 return super.acquireExclusiveReadLock(operations, file, exchange); 049 } 050 051 @Override 052 public void releaseExclusiveReadLockOnAbort(GenericFileOperations<File> operations, GenericFile<File> file, Exchange exchange) throws Exception { 053 // must call marker first 054 try { 055 if (markerFile) { 056 marker.releaseExclusiveReadLockOnAbort(operations, file, exchange); 057 } 058 } finally { 059 super.releaseExclusiveReadLockOnAbort(operations, file, exchange); 060 } 061 } 062 063 @Override 064 public void releaseExclusiveReadLockOnRollback(GenericFileOperations<File> operations, GenericFile<File> file, Exchange exchange) throws Exception { 065 // must call marker first 066 try { 067 if (markerFile) { 068 marker.releaseExclusiveReadLockOnRollback(operations, file, exchange); 069 } 070 } finally { 071 super.releaseExclusiveReadLockOnRollback(operations, file, exchange); 072 } 073 } 074 075 @Override 076 public void releaseExclusiveReadLockOnCommit(GenericFileOperations<File> operations, GenericFile<File> file, Exchange exchange) throws Exception { 077 // must call marker first 078 try { 079 if (markerFile) { 080 marker.releaseExclusiveReadLockOnCommit(operations, file, exchange); 081 } 082 } finally { 083 super.releaseExclusiveReadLockOnCommit(operations, file, exchange); 084 } 085 } 086 087 @Override 088 public void setMarkerFiler(boolean markerFile) { 089 this.markerFile = markerFile; 090 } 091 092}