org.apache.log4j.pattern.PropertiesPatternConverter Maven / Gradle / Ivy
/*
* 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.log4j.pattern;
import org.apache.log4j.spi.LoggingEvent;
import java.util.Iterator;
import java.util.Set;
import org.apache.log4j.helpers.*;
/**
* Able to handle the contents of the LoggingEvent's Property bundle and either
* output the entire contents of the properties in a similar format to the
* java.util.Hashtable.toString(), or to output the value of a specific key
* within the property bundle
* when this pattern converter has the option set.
*
* @author Paul Smith
* @author Ceki Gülcü
*/
public final class PropertiesPatternConverter
extends LoggingEventPatternConverter {
/**
* Name of property to output.
*/
private final String option;
/**
* Private constructor.
* @param options options, may be null.
*/
private PropertiesPatternConverter(
final String[] options) {
super(
((options != null) && (options.length > 0))
? ("Property{" + options[0] + "}") : "Properties", "property");
if ((options != null) && (options.length > 0)) {
option = options[0];
} else {
option = null;
}
}
/**
* Obtains an instance of PropertiesPatternConverter.
* @param options options, may be null or first element contains name of property to format.
* @return instance of PropertiesPatternConverter.
*/
public static PropertiesPatternConverter newInstance(
final String[] options) {
return new PropertiesPatternConverter(options);
}
/**
* {@inheritDoc}
*/
public void format(final LoggingEvent event, final StringBuffer toAppendTo) {
// if there is no additional options, we output every single
// Key/Value pair for the MDC in a similar format to Hashtable.toString()
if (option == null) {
toAppendTo.append("{");
try {
Set keySet = MDCKeySetExtractor.INSTANCE.getPropertyKeySet(event);
if (keySet != null) {
for (Iterator i = keySet.iterator(); i.hasNext();) {
Object item = i.next();
Object val = event.getMDC(item.toString());
toAppendTo.append("{").append(item).append(",").append(val).append(
"}");
}
}
} catch(Exception ex) {
LogLog.error("Unexpected exception while extracting MDC keys", ex);
}
toAppendTo.append("}");
} else {
// otherwise they just want a single key output
Object val = event.getMDC(option);
if (val != null) {
toAppendTo.append(val);
}
}
}
}