/*
* 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.slf4j.helpers;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.spi.AbstractLogger;
import org.apache.logging.log4j.spi.LoggerContext;
import org.apache.logging.slf4j.SLF4JLoggingException;
import org.slf4j.ILoggerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.impl.SLF4JLogger;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
*
*/
public class Log4JLoggerFactory implements ILoggerFactory {
private static final String FQCN = Log4JLoggerFactory.class.getName();
private static final String PACKAGE = "org.slf4j";
private final Map<LoggerContext, ConcurrentMap<String, Logger>> contextMap =
new WeakHashMap<LoggerContext, ConcurrentMap<String, Logger>>();
@Override
public Logger getLogger(final String name) {
final LoggerContext context = getContext();
final ConcurrentMap<String, Logger> loggers = getLoggersMap(context);
if (loggers.containsKey(name)) {
return loggers.get(name);
}
final String key = Logger.ROOT_LOGGER_NAME.equals(name) ? LogManager.ROOT_LOGGER_NAME : name;
final org.apache.logging.log4j.Logger logger = context.getLogger(key);
if (logger instanceof AbstractLogger) {
loggers.putIfAbsent(name, new SLF4JLogger((AbstractLogger) logger, name));
return loggers.get(name);
}
throw new SLF4JLoggingException("SLF4J Adapter requires base logging system to extend Log4J AbstractLogger");
}
private ConcurrentMap<String, Logger> getLoggersMap(final LoggerContext context) {
synchronized (contextMap) {
ConcurrentMap<String, Logger> map = contextMap.get(context);
if (map == null) {
map = new ConcurrentHashMap<String, Logger>();
contextMap.put(context, map);
}
return map;
}
}
private LoggerContext getContext() {
final Throwable t = new Throwable();
boolean next = false;
boolean pkg = false;
String fqcn = LoggerFactory.class.getName();
for (final StackTraceElement element : t.getStackTrace()) {
if (FQCN.equals(element.getClassName())) {
next = true;
continue;
}
if (next && element.getClassName().startsWith(PACKAGE)) {
fqcn = element.getClassName();
pkg = true;
continue;
}
if (pkg) {
break;
}
}
return PrivateManager.getContext(fqcn);
}
/**
* The real bridge between SLF4J and Log4j.
*/
private static class PrivateManager extends LogManager {
private static final String FQCN = LoggerFactory.class.getName();
public static LoggerContext getContext() {
return getContext(FQCN, false);
}
public static LoggerContext getContext(final String fqcn) {
return getContext(fqcn, false);
}
public static org.apache.logging.log4j.Logger getLogger(final String name) {
return getLogger(FQCN, name);
}
}
}