/*
* Copyright 2001-2004 The Apache Software Foundation.
*
* Licensed 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.util.Hashtable;
import org.slf4j.helpers.Util;
/**
* This class is a factory that creates and maintains org.apache.log4j.Loggers
* wrapping org.slf4j.Loggers.
*
* It keeps a hashtable of all created org.apache.log4j.Logger instances so that
* all newly created instances are not dulpicates of existing loggers.
*
* @author Sébastien Pennec
*/
class Log4jLoggerFactory {
// String, Logger
private static Hashtable log4jLoggers = new Hashtable();
private static final String LOG4J_DELEGATION_LOOP_URL = "http://www.slf4j.org/codes.html#log4jDelegationLoop";
// check for delegation loops
static {
try {
Class.forName("org.slf4j.impl.Log4jLoggerFactory");
String part1 = "Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError. ";
String part2 = "See also " + LOG4J_DELEGATION_LOOP_URL
+ " for more details.";
Util.report(part1);
Util.report(part2);
throw new IllegalStateException(part1 + part2);
} catch (ClassNotFoundException e) {
// this is the good case
}
}
public static synchronized Logger getLogger(String name) {
if (log4jLoggers.containsKey(name)) {
return (org.apache.log4j.Logger) log4jLoggers.get(name);
} else {
Logger log4jLogger = new Logger(name);
log4jLoggers.put(name, log4jLogger);
return log4jLogger;
}
}
}