org.apache.log4j.pattern.Log4j1NdcPatternConverter 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 java.util.List;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.pattern.ConverterKeys;
import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
import org.apache.logging.log4j.core.pattern.PatternConverter;
import org.apache.logging.log4j.util.Strings;
/**
* Returns the event's NDC in a StringBuilder.
*/
@Plugin(name = "Log4j1NdcPatternConverter", category = PatternConverter.CATEGORY)
@ConverterKeys({ "ndc" })
public final class Log4j1NdcPatternConverter extends LogEventPatternConverter {
/**
* Singleton.
*/
private static final Log4j1NdcPatternConverter INSTANCE =
new Log4j1NdcPatternConverter();
/**
* Private constructor.
*/
private Log4j1NdcPatternConverter() {
super("Log4j1NDC", "ndc");
}
/**
* Obtains an instance of NdcPatternConverter.
*
* @param options options, may be null.
* @return instance of NdcPatternConverter.
*/
public static Log4j1NdcPatternConverter newInstance(final String[] options) {
return INSTANCE;
}
@Override
public void format(final LogEvent event, final StringBuilder toAppendTo) {
final List ndc = event.getContextStack().asList();
toAppendTo.append(Strings.join(ndc, ' '));
}
}