122 lines
4.0 KiB
Java
122 lines
4.0 KiB
Java
|
|
/* ====================================================================
|
|
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.poi.util;
|
|
|
|
import java.util.HashMap;
|
|
import java.util.Map;
|
|
|
|
/**
|
|
* Provides logging without clients having to mess with
|
|
* configuration/initialization.
|
|
*
|
|
* @author Andrew C. Oliver (acoliver at apache dot org)
|
|
* @author Marc Johnson (mjohnson at apache dot org)
|
|
* @author Nicola Ken Barozzi (nicolaken at apache.org)
|
|
*/
|
|
@Internal
|
|
public final class POILogFactory {
|
|
/**
|
|
* Map of POILogger instances, with classes as keys
|
|
*/
|
|
private static final Map<String,POILogger> _loggers = new HashMap<String,POILogger>();
|
|
|
|
/**
|
|
* A common instance of NullLogger, as it does nothing
|
|
* we only need the one
|
|
*/
|
|
private static final POILogger _nullLogger = new NullLogger();
|
|
/**
|
|
* The name of the class to use. Initialised the
|
|
* first time we need it
|
|
*/
|
|
static String _loggerClassName = null;
|
|
|
|
/**
|
|
* Construct a POILogFactory.
|
|
*/
|
|
private POILogFactory() {}
|
|
|
|
/**
|
|
* Get a logger, based on a class name
|
|
*
|
|
* @param theclass the class whose name defines the log
|
|
*
|
|
* @return a POILogger for the specified class
|
|
*/
|
|
public static POILogger getLogger(final Class<?> theclass) {
|
|
return getLogger(theclass.getName());
|
|
}
|
|
|
|
/**
|
|
* Get a logger, based on a String
|
|
*
|
|
* @param cat the String that defines the log
|
|
*
|
|
* @return a POILogger for the specified class
|
|
*/
|
|
public static POILogger getLogger(final String cat) {
|
|
// If we haven't found out what logger to use yet,
|
|
// then do so now
|
|
// Don't look it up until we're first asked, so
|
|
// that our users can set the system property
|
|
// between class loading and first use
|
|
if(_loggerClassName == null) {
|
|
try {
|
|
_loggerClassName = System.getProperty("org.apache.poi.util.POILogger");
|
|
} catch(Exception e) {
|
|
// ignore any exception here
|
|
}
|
|
|
|
// Use the default logger if none specified,
|
|
// or none could be fetched
|
|
if(_loggerClassName == null) {
|
|
_loggerClassName = _nullLogger.getClass().getName();
|
|
}
|
|
}
|
|
|
|
// Short circuit for the null logger, which
|
|
// ignores all categories
|
|
if(_loggerClassName.equals(_nullLogger.getClass().getName())) {
|
|
return _nullLogger;
|
|
}
|
|
|
|
|
|
// Fetch the right logger for them, creating
|
|
// it if that's required
|
|
POILogger logger = _loggers.get(cat);
|
|
if (logger == null) {
|
|
try {
|
|
@SuppressWarnings("unchecked")
|
|
Class<? extends POILogger> loggerClass =
|
|
(Class<? extends POILogger>) Class.forName(_loggerClassName);
|
|
logger = loggerClass.newInstance();
|
|
logger.initialize(cat);
|
|
} catch(Exception e) {
|
|
// Give up and use the null logger
|
|
logger = _nullLogger;
|
|
_loggerClassName = _nullLogger.getClass().getName();
|
|
}
|
|
|
|
// Save for next time
|
|
_loggers.put(cat, logger);
|
|
}
|
|
return logger;
|
|
}
|
|
} |