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.logging.log4j.core.appender; 018 019 import java.io.BufferedOutputStream; 020 import java.io.File; 021 import java.io.FileNotFoundException; 022 import java.io.FileOutputStream; 023 import java.io.IOException; 024 import java.io.OutputStream; 025 import java.nio.channels.FileChannel; 026 import java.nio.channels.FileLock; 027 028 029 /** 030 * Manages actual File I/O for File Appenders. 031 */ 032 public class FileManager extends OutputStreamManager { 033 034 private static final FileManagerFactory FACTORY = new FileManagerFactory(); 035 036 private final boolean isAppend; 037 private final boolean isLocking; 038 039 protected FileManager(final String fileName, final OutputStream os, final boolean append, final boolean locking) { 040 super(os, fileName); 041 this.isAppend = append; 042 this.isLocking = locking; 043 } 044 045 /** 046 * Returns the FileManager. 047 * @param fileName The name of the file to manage. 048 * @param append true if the file should be appended to, false if it should be overwritten. 049 * @param locking true if the file should be locked while writing, false otherwise. 050 * @param bufferedIO true if the contents should be buffered as they are written. 051 * @return A FileManager for the File. 052 */ 053 public static FileManager getFileManager(final String fileName, final boolean append, boolean locking, 054 final boolean bufferedIO) { 055 056 if (locking && bufferedIO) { 057 locking = false; 058 } 059 return (FileManager) getManager(fileName, new FactoryData(append, locking, bufferedIO), FACTORY); 060 } 061 062 @Override 063 protected synchronized void write(final byte[] bytes, final int offset, final int length) { 064 065 if (isLocking) { 066 final FileChannel channel = ((FileOutputStream) getOutputStream()).getChannel(); 067 try { 068 /* Lock the whole file. This could be optimized to only lock from the current file 069 position. Note that locking may be advisory on some systems and mandatory on others, 070 so locking just from the current position would allow reading on systems where 071 locking is mandatory. Also, Java 6 will throw an exception if the region of the 072 file is already locked by another FileChannel in the same JVM. Hopefully, that will 073 be avoided since every file should have a single file manager - unless two different 074 files strings are configured that somehow map to the same file.*/ 075 final FileLock lock = channel.lock(0, Long.MAX_VALUE, false); 076 try { 077 super.write(bytes, offset, length); 078 } finally { 079 lock.release(); 080 } 081 } catch (final IOException ex) { 082 throw new AppenderRuntimeException("Unable to obtain lock on " + getName(), ex); 083 } 084 085 } else { 086 super.write(bytes, offset, length); 087 } 088 } 089 090 /** 091 * Returns the name of the File being managed. 092 * @return The name of the File being managed. 093 */ 094 public String getFileName() { 095 return getName(); 096 } 097 098 /** 099 * Returns the append status. 100 * @return true if the file will be appended to, false if it is overwritten. 101 */ 102 public boolean isAppend() { 103 return isAppend; 104 } 105 106 /** 107 * Returns the lock status. 108 * @return true if the file will be locked when writing, false otherwise. 109 */ 110 public boolean isLocking() { 111 return isLocking; 112 } 113 114 /** 115 * Factory Data. 116 */ 117 private static class FactoryData { 118 private final boolean append; 119 private final boolean locking; 120 private final boolean bufferedIO; 121 122 /** 123 * Constructor. 124 * @param append Append status. 125 * @param locking Locking status. 126 * @param bufferedIO Buffering flag. 127 */ 128 public FactoryData(final boolean append, final boolean locking, final boolean bufferedIO) { 129 this.append = append; 130 this.locking = locking; 131 this.bufferedIO = bufferedIO; 132 } 133 } 134 135 /** 136 * Factory to create a FileManager. 137 */ 138 private static class FileManagerFactory implements ManagerFactory<FileManager, FactoryData> { 139 140 /** 141 * Create a FileManager. 142 * @param name The name of the File. 143 * @param data The FactoryData 144 * @return The FileManager for the File. 145 */ 146 public FileManager createManager(final String name, final FactoryData data) { 147 final File file = new File(name); 148 final File parent = file.getParentFile(); 149 if (null != parent && !parent.exists()) { 150 parent.mkdirs(); 151 } 152 153 OutputStream os; 154 try { 155 os = new FileOutputStream(name, data.append); 156 if (data.bufferedIO) { 157 os = new BufferedOutputStream(os); 158 } 159 return new FileManager(name, os, data.append, data.locking); 160 } catch (final FileNotFoundException ex) { 161 LOGGER.error("FileManager (" + name + ") " + ex); 162 } 163 return null; 164 } 165 } 166 167 }