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 */ 017 018package org.apache.log4j.pattern; 019 020import org.apache.log4j.spi.LoggingEvent; 021 022import java.util.Iterator; 023import java.util.Set; 024import org.apache.log4j.helpers.*; 025 026 027/** 028 * Able to handle the contents of the LoggingEvent's Property bundle and either 029 * output the entire contents of the properties in a similar format to the 030 * java.util.Hashtable.toString(), or to output the value of a specific key 031 * within the property bundle 032 * when this pattern converter has the option set. 033 * 034 * @author Paul Smith 035 * @author Ceki Gülcü 036 */ 037public final class PropertiesPatternConverter 038 extends LoggingEventPatternConverter { 039 /** 040 * Name of property to output. 041 */ 042 private final String option; 043 044 /** 045 * Private constructor. 046 * @param options options, may be null. 047 */ 048 private PropertiesPatternConverter( 049 final String[] options) { 050 super( 051 ((options != null) && (options.length > 0)) 052 ? ("Property{" + options[0] + "}") : "Properties", "property"); 053 054 if ((options != null) && (options.length > 0)) { 055 option = options[0]; 056 } else { 057 option = null; 058 } 059 } 060 061 /** 062 * Obtains an instance of PropertiesPatternConverter. 063 * @param options options, may be null or first element contains name of property to format. 064 * @return instance of PropertiesPatternConverter. 065 */ 066 public static PropertiesPatternConverter newInstance( 067 final String[] options) { 068 return new PropertiesPatternConverter(options); 069 } 070 071 /** 072 * {@inheritDoc} 073 */ 074 public void format(final LoggingEvent event, final StringBuffer toAppendTo) { 075 // if there is no additional options, we output every single 076 // Key/Value pair for the MDC in a similar format to Hashtable.toString() 077 if (option == null) { 078 toAppendTo.append("{"); 079 080 try { 081 Set keySet = MDCKeySetExtractor.INSTANCE.getPropertyKeySet(event); 082 if (keySet != null) { 083 for (Iterator i = keySet.iterator(); i.hasNext();) { 084 Object item = i.next(); 085 Object val = event.getMDC(item.toString()); 086 toAppendTo.append("{").append(item).append(",").append(val).append( 087 "}"); 088 } 089 } 090 } catch(Exception ex) { 091 LogLog.error("Unexpected exception while extracting MDC keys", ex); 092 } 093 094 toAppendTo.append("}"); 095 } else { 096 // otherwise they just want a single key output 097 Object val = event.getMDC(option); 098 099 if (val != null) { 100 toAppendTo.append(val); 101 } 102 } 103 } 104}