org.apache.log4j.RollingFileAppender Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.log4j;
import java.io.IOException;
import java.io.Writer;
import java.io.File;
import java.io.InterruptedIOException;
import org.apache.log4j.helpers.OptionConverter;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.helpers.CountingQuietWriter;
import org.apache.log4j.spi.LoggingEvent;
/**
RollingFileAppender extends FileAppender to backup the log files when
they reach a certain size.
The log4j extras companion includes alternatives which should be considered
for new deployments and which are discussed in the documentation
for org.apache.log4j.rolling.RollingFileAppender.
@author Heinz Richter
@author Ceki Gülcü
*/
public class RollingFileAppender extends FileAppender {
/**
The default maximum file size is 10MB.
*/
protected long maxFileSize = 10*1024*1024;
/**
There is one backup file by default.
*/
protected int maxBackupIndex = 1;
private long nextRollover = 0;
/**
The default constructor simply calls its {@link
FileAppender#FileAppender parents constructor}. */
public
RollingFileAppender() {
super();
}
/**
Instantiate a RollingFileAppender and open the file designated by
filename. The opened filename will become the ouput
destination for this appender.
If the append parameter is true, the file will be
appended to. Otherwise, the file desginated by
filename will be truncated before being opened.
*/
public
RollingFileAppender(Layout layout, String filename, boolean append)
throws IOException {
super(layout, filename, append);
}
/**
Instantiate a FileAppender and open the file designated by
filename. The opened filename will become the output
destination for this appender.
The file will be appended to. */
public
RollingFileAppender(Layout layout, String filename) throws IOException {
super(layout, filename);
}
/**
Returns the value of the MaxBackupIndex option.
*/
public
int getMaxBackupIndex() {
return maxBackupIndex;
}
/**
Get the maximum size that the output file is allowed to reach
before being rolled over to backup files.
@since 1.1
*/
public
long getMaximumFileSize() {
return maxFileSize;
}
/**
Implements the usual roll over behaviour.
If MaxBackupIndex is positive, then files
{File.1, ..., File.MaxBackupIndex -1}
are renamed to {File.2, ...,
File.MaxBackupIndex}. Moreover, File is
renamed File.1 and closed. A new File is
created to receive further log output.
If MaxBackupIndex is equal to zero, then the
File is truncated with no backup files created.
*/
public // synchronization not necessary since doAppend is alreasy synched
void rollOver() {
File target;
File file;
if (qw != null) {
long size = ((CountingQuietWriter) qw).getCount();
LogLog.debug("rolling over count=" + size);
// if operation fails, do not roll again until
// maxFileSize more bytes are written
nextRollover = size + maxFileSize;
}
LogLog.debug("maxBackupIndex="+maxBackupIndex);
boolean renameSucceeded = true;
// If maxBackups <= 0, then there is no file renaming to be done.
if(maxBackupIndex > 0) {
// Delete the oldest file, to keep Windows happy.
file = new File(fileName + '.' + maxBackupIndex);
if (file.exists())
renameSucceeded = file.delete();
// Map {(maxBackupIndex - 1), ..., 2, 1} to {maxBackupIndex, ..., 3, 2}
for (int i = maxBackupIndex - 1; i >= 1 && renameSucceeded; i--) {
file = new File(fileName + "." + i);
if (file.exists()) {
target = new File(fileName + '.' + (i + 1));
LogLog.debug("Renaming file " + file + " to " + target);
renameSucceeded = file.renameTo(target);
}
}
if(renameSucceeded) {
// Rename fileName to fileName.1
target = new File(fileName + "." + 1);
this.closeFile(); // keep windows happy.
file = new File(fileName);
LogLog.debug("Renaming file " + file + " to " + target);
renameSucceeded = file.renameTo(target);
//
// if file rename failed, reopen file with append = true
//
if (!renameSucceeded) {
try {
this.setFile(fileName, true, bufferedIO, bufferSize);
}
catch(IOException e) {
if (e instanceof InterruptedIOException) {
Thread.currentThread().interrupt();
}
LogLog.error("setFile("+fileName+", true) call failed.", e);
}
}
}
}
//
// if all renames were successful, then
//
if (renameSucceeded) {
try {
// This will also close the file. This is OK since multiple
// close operations are safe.
this.setFile(fileName, false, bufferedIO, bufferSize);
nextRollover = 0;
}
catch(IOException e) {
if (e instanceof InterruptedIOException) {
Thread.currentThread().interrupt();
}
LogLog.error("setFile("+fileName+", false) call failed.", e);
}
}
}
public
synchronized
void setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)
throws IOException {
super.setFile(fileName, append, this.bufferedIO, this.bufferSize);
if(append) {
File f = new File(fileName);
((CountingQuietWriter) qw).setCount(f.length());
}
}
/**
Set the maximum number of backup files to keep around.
The MaxBackupIndex option determines how many backup
files are kept before the oldest is erased. This option takes
a positive integer value. If set to zero, then there will be no
backup files and the log file will be truncated when it reaches
MaxFileSize.
*/
public
void setMaxBackupIndex(int maxBackups) {
this.maxBackupIndex = maxBackups;
}
/**
Set the maximum size that the output file is allowed to reach
before being rolled over to backup files.
This method is equivalent to {@link #setMaxFileSize} except
that it is required for differentiating the setter taking a
long argument from the setter taking a
String argument by the JavaBeans {@link
java.beans.Introspector Introspector}.
@see #setMaxFileSize(String)
*/
public
void setMaximumFileSize(long maxFileSize) {
this.maxFileSize = maxFileSize;
}
/**
Set the maximum size that the output file is allowed to reach
before being rolled over to backup files.
In configuration files, the MaxFileSize option takes an
long integer in the range 0 - 2^63. You can specify the value
with the suffixes "KB", "MB" or "GB" so that the integer is
interpreted being expressed respectively in kilobytes, megabytes
or gigabytes. For example, the value "10KB" will be interpreted
as 10240.
*/
public
void setMaxFileSize(String value) {
maxFileSize = OptionConverter.toFileSize(value, maxFileSize + 1);
}
protected
void setQWForFiles(Writer writer) {
this.qw = new CountingQuietWriter(writer, errorHandler);
}
/**
This method differentiates RollingFileAppender from its super
class.
@since 0.9.0
*/
protected
void subAppend(LoggingEvent event) {
super.subAppend(event);
if(fileName != null && qw != null) {
long size = ((CountingQuietWriter) qw).getCount();
if (size >= maxFileSize && size >= nextRollover) {
rollOver();
}
}
}
}