/*
* JBoss, Home of Professional Open Source.
* Copyright 2013, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.logging.logmanager;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import java.util.logging.Formatter;
import org.apache.log4j.Appender;
import org.apache.log4j.Category;
import org.apache.log4j.Layout;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.spi.OptionHandler;
import org.jboss.as.logging.LoggingMessages;
import org.jboss.logmanager.ExtHandler;
import org.jboss.logmanager.ExtLogRecord;
/**
* Wraps a {@link Appender log4j appender} to a {@link ExtHandler handler}.
*
* @author <a href="mailto:jperkins@redhat.com">James R. Perkins</a>
*/
public class Log4jAppenderHandler extends ExtHandler {
private volatile Appender appender = null;
private final boolean applyLayout;
private static final AtomicReferenceFieldUpdater<Log4jAppenderHandler, Appender> appenderUpdater = AtomicReferenceFieldUpdater.newUpdater(Log4jAppenderHandler.class, Appender.class, "appender");
public Log4jAppenderHandler() {
applyLayout = true;
}
/**
* Construct a new instance.
*
* @param appender the appender to delegate to
*/
public Log4jAppenderHandler(final Appender appender) {
// Should be true as the formatter will always be set
this(appender, true);
}
/**
* Construct a new instance, possibly applying a {@code Layout} to the given appender instance.
*
* @param appender the appender to delegate to
* @param applyLayout {@code true} to apply an emulated layout, {@code false} otherwise
*/
public Log4jAppenderHandler(final Appender appender, final boolean applyLayout) {
this.applyLayout = applyLayout;
if (applyLayout) {
appender.setLayout(null);
}
appenderUpdater.set(this, appender);
}
/**
* Get the log4j appender.
*
* @return the log4j appender
*/
public Appender getAppender() {
return appender;
}
/**
* Activates the appender only if it's an {@link OptionHandler option handler}.
*/
public void activate() {
if (appender instanceof OptionHandler) {
((OptionHandler) appender).activateOptions();
}
}
/**
* Set the Log4j appender.
*
* @param appender the log4j appender
*/
public void setAppender(final Appender appender) {
if (this.appender != null) {
close();
}
checkAccess(this);
if (applyLayout && appender != null) {
final Formatter formatter = getFormatter();
appender.setLayout(formatter == null ? null : new FormatterLayout(formatter));
}
appenderUpdater.set(this, appender);
}
@Override
public void setFormatter(final Formatter newFormatter) throws SecurityException {
if (applyLayout) {
final Appender appender = this.appender;
if (appender != null) {
appender.setLayout(new FormatterLayout(newFormatter));
}
}
super.setFormatter(newFormatter);
}
@Override
protected void doPublish(final ExtLogRecord record) {
final Appender appender = this.appender;
if (appender == null) {
throw LoggingMessages.MESSAGES.handlerClosed();
}
final LoggingEvent event = new LoggingEvent(record, DummyCategory.of(record.getLoggerName()));
appender.doAppend(event);
super.doPublish(record);
}
@Override
public void flush() {
// Do nothing (there is no equivalent method on log4j appenders).
}
@Override
public void close() throws SecurityException {
checkAccess(this);
final Appender appender = appenderUpdater.getAndSet(this, null);
if (appender != null) {
appender.close();
}
}
/**
* Dummy category for the logging event
*/
private static final class DummyCategory extends Category {
static DummyCategory of(final String name) {
return new DummyCategory(name);
}
protected DummyCategory(String name) {
super(name);
}
}
/**
* An emulator for log4j {@code Layout}s.
*
* @author <a href="mailto:david.lloyd@redhat.com">David M. Lloyd</a>
*/
public final class FormatterLayout extends Layout {
private final Formatter formatter;
/**
* Construct a new instance.
*
* @param formatter the formatter to delegate to
*/
public FormatterLayout(final Formatter formatter) {
this.formatter = formatter;
}
@Override
public String format(final LoggingEvent event) {
return formatter.format(event.getLogRecord());
}
@Override
public boolean ignoresThrowable() {
// just be safe
return false;
}
@Override
public void activateOptions() {
// options are always activated already
}
}
}