001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.pattern;
018
019import org.apache.logging.log4j.core.LogEvent;
020import org.apache.logging.log4j.core.config.plugins.Plugin;
021
022
023/**
024 * Returns the event's NDC in a StringBuilder.
025 */
026@Plugin(name = "NdcPatternConverter", category = PatternConverter.CATEGORY)
027@ConverterKeys({ "x", "NDC" })
028public final class NdcPatternConverter extends LogEventPatternConverter {
029  /**
030   *   Singleton.
031   */
032  private static final NdcPatternConverter INSTANCE =
033    new NdcPatternConverter();
034
035  /**
036   * Private constructor.
037   */
038  private NdcPatternConverter() {
039    super("NDC", "ndc");
040  }
041
042  /**
043   * Obtains an instance of NdcPatternConverter.
044   * @param options options, may be null.
045   * @return instance of NdcPatternConverter.
046   */
047  public static NdcPatternConverter newInstance(final String[] options) {
048    return INSTANCE;
049  }
050
051  /**
052   * {@inheritDoc}
053   */
054  @Override
055public void format(final LogEvent event, final StringBuilder toAppendTo) {
056    toAppendTo.append(event.getContextStack());
057  }
058}