/*
* 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.rolling;
import org.apache.log4j.Appender;
import org.apache.log4j.FileAppender;
import org.apache.log4j.Logger;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.helpers.QuietWriter;
import org.apache.log4j.rolling.helper.Action;
import org.apache.log4j.spi.ErrorHandler;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.spi.OptionHandler;
import org.apache.log4j.xml.UnrecognizedElementHandler;
import org.w3c.dom.Element;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Properties;
/**
* <code>RollingFileAppender</code> extends {@link FileAppender} to backup the log files
* depending on {@link RollingPolicy} and {@link TriggeringPolicy}.
* <p>
* To be of any use, a <code>RollingFileAppender</code> instance must have both
* a <code>RollingPolicy</code> and a <code>TriggeringPolicy</code> set up.
* However, if its <code>RollingPolicy</code> also implements the
* <code>TriggeringPolicy</code> interface, then only the former needs to be
* set up. For example, {@link TimeBasedRollingPolicy} acts both as a
* <code>RollingPolicy</code> and a <code>TriggeringPolicy</code>.
*
* <p><code>RollingFileAppender</code> can be configured programattically or
* using {@link org.apache.log4j.extras.DOMConfigurator} or
* {@link org.apache.log4j.xml.DOMConfigurator} in log4j 1.2.15 or later. Here is a sample
* configration file:
<pre><?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration>
<log4j:configuration debug="true">
<appender name="ROLL" class="org.apache.log4j.rolling.RollingFileAppender">
<b><rollingPolicy class="org.apache.log4j.rolling.TimeBasedRollingPolicy">
<param name="FileNamePattern" value="/wombat/foo.%d{yyyy-MM}.gz"/>
</rollingPolicy></b>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%c{1} - %m%n"/>
</layout>
</appender>
<root">
<appender-ref ref="ROLL"/>
</root>
</log4j:configuration>
</pre>
*<p>This configuration file specifies a monthly rollover schedule including
* automatic compression of the archived files. See
* {@link TimeBasedRollingPolicy} for more details.
*
* @author Heinz Richter
* @author Ceki Gülcü
* @since 1.3
* */
public final class RollingFileAppender extends FileAppender
implements UnrecognizedElementHandler {
/**
* Triggering policy.
*/
private TriggeringPolicy triggeringPolicy;
/**
* Rolling policy.
*/
private RollingPolicy rollingPolicy;
/**
* Length of current active log file.
*/
private long fileLength = 0;
/**
* Asynchronous action (like compression) from previous rollover.
*/
private Action lastRolloverAsyncAction = null;
/**
* Construct a new instance.
*/
public RollingFileAppender() {
}
/**
* Prepare instance of use.
*/
public void activateOptions() {
if (rollingPolicy == null) {
LogLog.warn(
"Please set a rolling policy for the RollingFileAppender named '"
+ getName() + "'");
return;
}
//
// if no explicit triggering policy and rolling policy is both.
//
if (
(triggeringPolicy == null) && rollingPolicy instanceof TriggeringPolicy) {
triggeringPolicy = (TriggeringPolicy) rollingPolicy;
}
if (triggeringPolicy == null) {
LogLog.warn(
"Please set a TriggeringPolicy for the RollingFileAppender named '"
+ getName() + "'");
return;
}
Exception exception = null;
synchronized (this) {
triggeringPolicy.activateOptions();
rollingPolicy.activateOptions();
try {
RolloverDescription rollover =
rollingPolicy.initialize(getFile(), getAppend());
if (rollover != null) {
Action syncAction = rollover.getSynchronous();
if (syncAction != null) {
syncAction.execute();
}
setFile(rollover.getActiveFileName());
setAppend(rollover.getAppend());
lastRolloverAsyncAction = rollover.getAsynchronous();
if (lastRolloverAsyncAction != null) {
Thread runner = new Thread(lastRolloverAsyncAction);
runner.start();
}
}
File activeFile = new File(getFile());
if (getAppend()) {
fileLength = activeFile.length();
} else {
fileLength = 0;
}
super.activateOptions();
} catch (Exception ex) {
exception = ex;
}
}
if (exception != null) {
LogLog.warn(
"Exception while initializing RollingFileAppender named '" + getName()
+ "'", exception);
}
}
private QuietWriter createQuietWriter(final Writer writer) {
ErrorHandler handler = errorHandler;
if (handler == null) {
handler = new DefaultErrorHandler(this);
}
return new QuietWriter(writer, handler);
}
/**
Implements the usual roll over behaviour.
<p>If <code>MaxBackupIndex</code> is positive, then files
{<code>File.1</code>, ..., <code>File.MaxBackupIndex -1</code>}
are renamed to {<code>File.2</code>, ...,
<code>File.MaxBackupIndex</code>}. Moreover, <code>File</code> is
renamed <code>File.1</code> and closed. A new <code>File</code> is
created to receive further log output.
<p>If <code>MaxBackupIndex</code> is equal to zero, then the
<code>File</code> is truncated with no backup files created.
* @return true if rollover performed.
*/
public boolean rollover() {
//
// can't roll without a policy
//
if (rollingPolicy != null) {
Exception exception = null;
synchronized (this) {
//
// if a previous async task is still running
//}
if (lastRolloverAsyncAction != null) {
//
// block until complete
//
lastRolloverAsyncAction.close();
//
// or don't block and return to rollover later
//
//if (!lastRolloverAsyncAction.isComplete()) return false;
}
try {
RolloverDescription rollover = rollingPolicy.rollover(getFile());
if (rollover != null) {
if (rollover.getActiveFileName().equals(getFile())) {
closeWriter();
boolean success = true;
if (rollover.getSynchronous() != null) {
success = false;
try {
success = rollover.getSynchronous().execute();
} catch (Exception ex) {
exception = ex;
}
}
if (success) {
if (rollover.getAppend()) {
fileLength = new File(rollover.getActiveFileName()).length();
} else {
fileLength = 0;
}
if (rollover.getAsynchronous() != null) {
lastRolloverAsyncAction = rollover.getAsynchronous();
new Thread(lastRolloverAsyncAction).start();
}
setFile(
rollover.getActiveFileName(), rollover.getAppend(),
bufferedIO, bufferSize);
} else {
setFile(
rollover.getActiveFileName(), true, bufferedIO, bufferSize);
if (exception == null) {
LogLog.warn("Failure in post-close rollover action");
} else {
LogLog.warn(
"Exception in post-close rollover action", exception);
}
}
} else {
Writer newWriter =
createWriter(
new FileOutputStream(
rollover.getActiveFileName(), rollover.getAppend()));
closeWriter();
setFile(rollover.getActiveFileName());
this.qw = createQuietWriter(newWriter);
boolean success = true;
if (rollover.getSynchronous() != null) {
success = false;
try {
success = rollover.getSynchronous().execute();
} catch (Exception ex) {
exception = ex;
}
}
if (success) {
if (rollover.getAppend()) {
fileLength = new File(rollover.getActiveFileName()).length();
} else {
fileLength = 0;
}
if (rollover.getAsynchronous() != null) {
lastRolloverAsyncAction = rollover.getAsynchronous();
new Thread(lastRolloverAsyncAction).start();
}
}
writeHeader();
}
return true;
}
} catch (Exception ex) {
exception = ex;
}
}
if (exception != null) {
LogLog.warn(
"Exception during rollover, rollover deferred.", exception);
}
}
return false;
}
/**
* {@inheritDoc}
*/
protected void subAppend(final LoggingEvent event) {
// The rollover check must precede actual writing. This is the
// only correct behavior for time driven triggers.
if (
triggeringPolicy.isTriggeringEvent(
this, event, getFile(), getFileLength())) {
//
// wrap rollover request in try block since
// rollover may fail in case read access to directory
// is not provided. However appender should still be in good
// condition and the append should still happen.
try {
rollover();
} catch (Exception ex) {
LogLog.warn("Exception during rollover attempt.", ex);
}
}
super.subAppend(event);
}
/**
* Get rolling policy.
* @return rolling policy.
*/
public RollingPolicy getRollingPolicy() {
return rollingPolicy;
}
/**
* Get triggering policy.
* @return triggering policy.
*/
public TriggeringPolicy getTriggeringPolicy() {
return triggeringPolicy;
}
/**
* Sets the rolling policy.
* @param policy rolling policy.
*/
public void setRollingPolicy(final RollingPolicy policy) {
rollingPolicy = policy;
}
/**
* Set triggering policy.
* @param policy triggering policy.
*/
public void setTriggeringPolicy(final TriggeringPolicy policy) {
triggeringPolicy = policy;
}
/**
* Close appender. Waits for any asynchronous file compression actions to be completed.
*/
public void close() {
synchronized (this) {
if (lastRolloverAsyncAction != null) {
lastRolloverAsyncAction.close();
}
}
super.close();
}
/**
Returns an OutputStreamWriter when passed an OutputStream. The
encoding used will depend on the value of the
<code>encoding</code> property. If the encoding value is
specified incorrectly the writer will be opened using the default
system encoding (an error message will be printed to the loglog.
@param os output stream, may not be null.
@return new writer.
*/
protected OutputStreamWriter createWriter(final OutputStream os) {
return super.createWriter(new CountingOutputStream(os, this));
}
/**
* Get byte length of current active log file.
* @return byte length of current active log file.
*/
public long getFileLength() {
return fileLength;
}
/**
* Increments estimated byte length of current active log file.
* @param increment additional bytes written to log file.
*/
public synchronized void incrementFileLength(int increment) {
fileLength += increment;
}
/**
* {@inheritDoc}
*/
public boolean parseUnrecognizedElement(final Element element,
final Properties props) throws Exception {
final String nodeName = element.getNodeName();
if ("rollingPolicy".equals(nodeName)) {
OptionHandler rollingPolicy =
org.apache.log4j.extras.DOMConfigurator.parseElement(
element, props, RollingPolicy.class);
if (rollingPolicy != null) {
rollingPolicy.activateOptions();
this.setRollingPolicy((RollingPolicy) rollingPolicy);
}
return true;
}
if ("triggeringPolicy".equals(nodeName)) {
OptionHandler triggerPolicy =
org.apache.log4j.extras.DOMConfigurator.parseElement(
element, props, TriggeringPolicy.class);
if (triggerPolicy != null) {
triggerPolicy.activateOptions();
this.setTriggeringPolicy((TriggeringPolicy) triggerPolicy);
}
return true;
}
return false;
}
/**
* Wrapper for OutputStream that will report all write
* operations back to this class for file length calculations.
*/
private static class CountingOutputStream extends OutputStream {
/**
* Wrapped output stream.
*/
private final OutputStream os;
/**
* Rolling file appender to inform of stream writes.
*/
private final RollingFileAppender rfa;
/**
* Constructor.
* @param os output stream to wrap.
* @param rfa rolling file appender to inform.
*/
public CountingOutputStream(
final OutputStream os, final RollingFileAppender rfa) {
this.os = os;
this.rfa = rfa;
}
/**
* {@inheritDoc}
*/
public void close() throws IOException {
os.close();
}
/**
* {@inheritDoc}
*/
public void flush() throws IOException {
os.flush();
}
/**
* {@inheritDoc}
*/
public void write(final byte[] b) throws IOException {
os.write(b);
rfa.incrementFileLength(b.length);
}
/**
* {@inheritDoc}
*/
public void write(final byte[] b, final int off, final int len)
throws IOException {
os.write(b, off, len);
rfa.incrementFileLength(len);
}
/**
* {@inheritDoc}
*/
public void write(final int b) throws IOException {
os.write(b);
rfa.incrementFileLength(1);
}
}
private static final class DefaultErrorHandler implements ErrorHandler {
private final RollingFileAppender appender;
public DefaultErrorHandler(final RollingFileAppender appender) {
this.appender = appender;
}
/**@since 1.2*/
public void setLogger(Logger logger) {
}
public void error(String message, Exception ioe, int errorCode) {
appender.close();
LogLog.error("IO failure for appender named "+ appender.getName(), ioe);
}
public void error(String message) {
}
/**@since 1.2*/
public void error(String message, Exception e, int errorCode, LoggingEvent event) {
}
/**@since 1.2*/
public void setAppender(Appender appender) {
}
/**@since 1.2*/
public void setBackupAppender(Appender appender) {
}
public void activateOptions() {
}
}
}