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; 019 020 021/** 022 023 <p>PatternConverter is an abstract class that provides the 024 formatting functionality that derived classes need. 025 026 <p>Conversion specifiers in a conversion patterns are parsed to 027 individual PatternConverters. Each of which is responsible for 028 converting an object in a converter specific manner. 029 030 @author <a href="mailto:cakalijp@Maritz.com">James P. Cakalic</a> 031 @author Ceki Gülcü 032 @author Chris Nokes 033 @author Curt Arnold 034 035 */ 036public abstract class PatternConverter { 037 /** 038 * Converter name. 039 */ 040 private final String name; 041 042 /** 043 * Converter style name. 044 */ 045 private final String style; 046 047 /** 048 * Create a new pattern converter. 049 * @param name name for pattern converter. 050 * @param style CSS style for formatted output. 051 */ 052 protected PatternConverter(final String name, final String style) { 053 this.name = name; 054 this.style = style; 055 } 056 057 /** 058 * Formats an object into a string buffer. 059 * @param obj event to format, may not be null. 060 * @param toAppendTo string buffer to which the formatted event will be appended. May not be null. 061 */ 062 public abstract void format(final Object obj, final StringBuffer toAppendTo); 063 064 /** 065 * This method returns the name of the conversion pattern. 066 * 067 * The name can be useful to certain Layouts such as HTMLLayout. 068 * 069 * @return the name of the conversion pattern 070 */ 071 public final String getName() { 072 return name; 073 } 074 075 /** 076 * This method returns the CSS style class that should be applied to 077 * the LoggingEvent passed as parameter, which can be null. 078 * 079 * This information is currently used only by HTMLLayout. 080 * 081 * @param e null values are accepted 082 * @return the name of the conversion pattern 083 */ 084 public String getStyleClass(Object e) { 085 return style; 086 } 087}