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/**
* Copyright 2007-2012 Arthur Blake
*
* 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 net.sf.log4jdbc.log;
import net.sf.log4jdbc.Properties;
import net.sf.log4jdbc.log.log4j2.Log4j2SpyLogDelegator;
/**
* A provider for a SpyLogDelegator. This allows a single switch point to abstract
* away which logging system to use for spying on JDBC calls.
*
* Modifications for log4j2:
*
* - addition of the
#loadSpyLogDelegator() method
* to choose between the new Log4j2SpyLogDelegator,
* or an alternative SpyLogDelegator.
* This method uses net.sf.log4jdbc.log4j2.Properties#getSpyLogDelegatorName()
* to determine which logger to use.
* - Use of this method to set the
logger attribute
* if null when calling #getSpyLogDelegator().
* - From load4jdbc-remix, addition of a method to set a custom
SpyLogDelegator
*
*
* @author Arthur Blake
* @author Frederic Bastian
* @author Tim Azzopardi from log4jdbc-remix
* @author Mathieu Seppey
*/
public class SpyLogFactory
{
/**
* Do not allow instantiation. Access is through static method.
*/
private SpyLogFactory() {}
/**
* The logging system of choice.
* Default value is Log4j2SpyLogDelegator
*/
private static SpyLogDelegator logger;
/**
* Return the SpyLogDelegator.
* If not already initialized (for instance, using
* {@link #setSpyLogDelegator(SpyLogDelegator)}), this getter will load it first,
* using the {@link net.sf.log4jdbc.log4j2.Properties#getSpyLogDelegatorName()}.
* If the name is null, load {@link net.sf.log4jdbc.log4j2.Log4j2SpyLogDelegator},
* otherwise, try to load the corresponding class.
*
* @return The SpyLogDelegator to use.
* @see #setSpyLogDelegator(SpyLogDelegator)
*/
public static SpyLogDelegator getSpyLogDelegator()
{
if (logger == null) {
loadSpyLogDelegator(Properties.getSpyLogDelegatorName());
}
return logger;
}
/**
* Set the appropriate SpyLogDelegator
* depending on spyLogDelegatorName.
* If null, load {@link net.sf.log4jdbc.log4j2.Log4j2SpyLogDelegator},
* otherwise, try to load the corresponding class.
*
* @param spyLogDelegatorName A String representing the name
* of the class implementing SpyLogDelegator
* to load. If null,
* load Log4j2SpyLogDelegator.
* @see Slf4jSpyLogDelegator
* @see net.sf.log4jdbc.log4j2.Log4j2SpyLogDelegator
*/
public static void loadSpyLogDelegator(String spyLogDelegatorName)
{
if (spyLogDelegatorName == null) {
try{
setSpyLogDelegator(new Log4j2SpyLogDelegator());
}
catch(NoClassDefFoundError e){
throw new NoClassDefFoundError("Unable to find Log4j2 as default logging library. " +
"Please provide a logging library and configure a valid spyLogDelegator name in the properties file.");
}
} else {
try {
Object loadedClass =
Class.forName(spyLogDelegatorName).newInstance();
if (loadedClass == null) {
throw new IllegalArgumentException(
"spyLogDelegatorName loads a null SpyLogDelegator");
}
setSpyLogDelegator((SpyLogDelegator) loadedClass);
} catch (Exception e) {
throw new IllegalArgumentException(
"spyLogDelegatorName does not allow to load a valid SpyLogDelegator: " +
e.getMessage());
} catch (NoClassDefFoundError e) {
throw new NoClassDefFoundError("Cannot find a library corresponding to the property log4jdbc.spylogdelegator.name. " +
"Please provide a logging library and configure a valid spyLogDelegator name in the properties file.");
}
}
}
/**
* @param logDelegator the log delegator responsible for actually logging
* JDBC events.
*/
public static void setSpyLogDelegator(SpyLogDelegator logDelegator) {
if (logDelegator == null) {
throw new IllegalArgumentException("log4jdbc: logDelegator cannot be null.");
}
logger = logDelegator;
}
}