| /* Copyright 2017, 2018 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.xmlbeans.impl.common; |
| |
| 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) |
| */ |
| public final class XBLogFactory { |
| /** |
| * Map of XBLogger instances, with classes as keys |
| */ |
| private static final Map<String,XBLogger> _loggers = new HashMap<String,XBLogger>(); |
| |
| /** |
| * A common instance of NullLogger, as it does nothing |
| * we only need the one |
| */ |
| private static final XBLogger _nullLogger = new NullLogger(); |
| /** |
| * The name of the class to use. Initialised the |
| * first time we need it |
| */ |
| static String _loggerClassName = null; |
| |
| /** |
| * Construct a XBLogFactory. |
| */ |
| private XBLogFactory() {} |
| |
| /** |
| * Get a logger, based on a class name |
| * |
| * @param theclass the class whose name defines the log |
| * |
| * @return a XBLogger for the specified class |
| */ |
| public static XBLogger 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 XBLogger for the specified class |
| */ |
| public static XBLogger 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.xmlbeans.impl.store.XBLogger"); |
| } 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 |
| XBLogger logger = _loggers.get(cat); |
| if (logger == null) { |
| try { |
| @SuppressWarnings("unchecked") |
| Class<? extends XBLogger> loggerClass = |
| (Class<? extends XBLogger>) 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; |
| } |
| } |
| |
| |