org.apache.logging.slf4j.Log4jMarkerFactory Maven / Gradle / Ivy
/*
* 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.logging.slf4j;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.MarkerManager;
import org.apache.logging.log4j.status.StatusLogger;
import org.slf4j.IMarkerFactory;
import org.slf4j.Marker;
/**
* Log4j/SLF4J bridge to create SLF4J Markers based on name or based on existing SLF4J Markers.
*/
public class Log4jMarkerFactory implements IMarkerFactory {
private static final Logger LOGGER = StatusLogger.getLogger();
private final ConcurrentMap markerMap = new ConcurrentHashMap<>();
/**
* Returns a Log4j Marker that is compatible with SLF4J.
* @param name The name of the Marker.
* @return A Marker.
*/
@Override
public Marker getMarker(final String name) {
if (name == null) {
throw new IllegalArgumentException("Marker name must not be null");
}
final Marker marker = markerMap.get(name);
if (marker != null) {
return marker;
}
final org.apache.logging.log4j.Marker log4jMarker = MarkerManager.getMarker(name);
return addMarkerIfAbsent(name, log4jMarker);
}
private Marker addMarkerIfAbsent(final String name, final org.apache.logging.log4j.Marker log4jMarker) {
final Marker marker = new Log4jMarker(log4jMarker);
final Marker existing = markerMap.putIfAbsent(name, marker);
return existing == null ? marker : existing;
}
/**
* Returns a Log4j Marker converted from an existing custom SLF4J Marker.
* @param marker The SLF4J Marker to convert.
* @return A converted Log4j/SLF4J Marker.
* @since 2.1
*/
public Marker getMarker(final Marker marker) {
if (marker == null) {
throw new IllegalArgumentException("Marker must not be null");
}
final Marker m = markerMap.get(marker.getName());
if (m != null) {
return m;
}
return addMarkerIfAbsent(marker.getName(), convertMarker(marker));
}
private static org.apache.logging.log4j.Marker convertMarker(final Marker original) {
if (original == null) {
throw new IllegalArgumentException("Marker must not be null");
}
return convertMarker(original, new ArrayList());
}
private static org.apache.logging.log4j.Marker convertMarker(final Marker original,
final Collection visited) {
final org.apache.logging.log4j.Marker marker = MarkerManager.getMarker(original.getName());
if (original.hasReferences()) {
final Iterator it = original.iterator();
while (it.hasNext()) {
final Marker next = it.next();
if (visited.contains(next)) {
LOGGER.warn("Found a cycle in Marker [{}]. Cycle will be broken.", next.getName());
} else {
visited.add(next);
marker.addParents(convertMarker(next, visited));
}
}
}
return marker;
}
/**
* Returns true if the Marker exists.
* @param name The Marker name.
* @return {@code true} if the Marker exists, {@code false} otherwise.
*/
@Override
public boolean exists(final String name) {
return markerMap.containsKey(name);
}
/**
* Log4j does not support detached Markers. This method always returns false.
* @param name The Marker name.
* @return {@code false}
*/
@Override
public boolean detachMarker(final String name) {
return false;
}
/**
* Log4j does not support detached Markers for performance reasons. The returned Marker is attached.
* @param name The Marker name.
* @return The named Marker (unmodified).
*/
@Override
public Marker getDetachedMarker(final String name) {
LOGGER.warn("Log4j does not support detached Markers. Returned Marker [{}] will be unchanged.", name);
return getMarker(name);
}
}