1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache license, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the license for the specific language governing permissions and 15 * limitations under the license. 16 */ 17 package org.apache.logging.log4j.core.pattern; 18 19 import org.apache.logging.log4j.core.LogEvent; 20 import org.apache.logging.log4j.core.config.plugins.Plugin; 21 22 23 /** 24 * Returns the event's NDC in a StringBuilder. 25 */ 26 @Plugin(name = "NdcPatternConverter", category = PatternConverter.CATEGORY) 27 @ConverterKeys({ "x", "NDC" }) 28 public final class NdcPatternConverter extends LogEventPatternConverter { 29 /** 30 * Singleton. 31 */ 32 private static final NdcPatternConverter INSTANCE = 33 new NdcPatternConverter(); 34 35 /** 36 * Private constructor. 37 */ 38 private NdcPatternConverter() { 39 super("NDC", "ndc"); 40 } 41 42 /** 43 * Obtains an instance of NdcPatternConverter. 44 * @param options options, may be null. 45 * @return instance of NdcPatternConverter. 46 */ 47 public static NdcPatternConverter newInstance(final String[] options) { 48 return INSTANCE; 49 } 50 51 /** 52 * {@inheritDoc} 53 */ 54 @Override 55 public void format(final LogEvent event, final StringBuilder toAppendTo) { 56 toAppendTo.append(event.getContextStack()); 57 } 58 }