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 package org.apache.logging.log4j.core.layout; 018 019 import org.apache.logging.log4j.core.LogEvent; 020 import org.apache.logging.log4j.core.config.Configuration; 021 import org.apache.logging.log4j.core.config.plugins.Plugin; 022 import org.apache.logging.log4j.core.config.plugins.PluginAttr; 023 import org.apache.logging.log4j.core.config.plugins.PluginConfiguration; 024 import org.apache.logging.log4j.core.config.plugins.PluginElement; 025 import org.apache.logging.log4j.core.config.plugins.PluginFactory; 026 import org.apache.logging.log4j.core.helpers.Charsets; 027 import org.apache.logging.log4j.core.helpers.OptionConverter; 028 import org.apache.logging.log4j.core.pattern.LogEventPatternConverter; 029 import org.apache.logging.log4j.core.pattern.PatternFormatter; 030 import org.apache.logging.log4j.core.pattern.PatternParser; 031 import org.apache.logging.log4j.core.pattern.RegexReplacement; 032 033 import java.nio.charset.Charset; 034 import java.util.HashMap; 035 import java.util.List; 036 import java.util.Map; 037 038 /** 039 * <p>A flexible layout configurable with pattern string. The goal of this class 040 * is to {@link org.apache.logging.log4j.core.Layout#toByteArray format} a {@link LogEvent} and return the results. 041 * The format of the result depends on the <em>conversion pattern</em>. 042 * <p> 043 * <p/> 044 * <p>The conversion pattern is closely related to the conversion 045 * pattern of the printf function in C. A conversion pattern is 046 * composed of literal text and format control expressions called 047 * <em>conversion specifiers</em>. 048 * 049 * See the Log4j Manual for details on the supported pattern converters. 050 */ 051 @Plugin(name = "PatternLayout", category = "Core", elementType = "layout", printObject = true) 052 public final class PatternLayout extends AbstractStringLayout { 053 /** 054 * Default pattern string for log output. Currently set to the 055 * string <b>"%m%n"</b> which just prints the application supplied 056 * message. 057 */ 058 public static final String DEFAULT_CONVERSION_PATTERN = "%m%n"; 059 060 /** 061 * A conversion pattern equivalent to the TTCCCLayout. 062 * Current value is <b>%r [%t] %p %c %x - %m%n</b>. 063 */ 064 public static final String TTCC_CONVERSION_PATTERN = 065 "%r [%t] %p %c %x - %m%n"; 066 067 /** 068 * A simple pattern. 069 * Current value is <b>%d [%t] %p %c - %m%n</b>. 070 */ 071 public static final String SIMPLE_CONVERSION_PATTERN = 072 "%d [%t] %p %c - %m%n"; 073 074 /** Key to identify pattern converters. */ 075 public static final String KEY = "Converter"; 076 077 /** 078 * Initial converter for pattern. 079 */ 080 private List<PatternFormatter> formatters; 081 082 /** 083 * Conversion pattern. 084 */ 085 private final String conversionPattern; 086 087 088 /** 089 * The current Configuration. 090 */ 091 private final Configuration config; 092 093 private final RegexReplacement replace; 094 095 private final boolean handleExceptions; 096 097 /** 098 * Constructs a EnhancedPatternLayout using the supplied conversion pattern. 099 * 100 * @param config The Configuration. 101 * @param replace The regular expression to match. 102 * @param pattern conversion pattern. 103 * @param charset The character set. 104 * @param handleExceptions Whether or not exceptions should always be handled in this pattern (if {@code true}, 105 * exceptions will be written even if the pattern does not specify so). 106 */ 107 private PatternLayout(final Configuration config, final RegexReplacement replace, final String pattern, 108 final Charset charset, boolean handleExceptions) { 109 super(charset); 110 this.replace = replace; 111 this.conversionPattern = pattern; 112 this.config = config; 113 this.handleExceptions = handleExceptions; 114 final PatternParser parser = createPatternParser(config); 115 formatters = parser.parse(pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, this.handleExceptions); 116 } 117 118 /** 119 * Set the <b>ConversionPattern</b> option. This is the string which 120 * controls formatting and consists of a mix of literal content and 121 * conversion specifiers. 122 * 123 * @param conversionPattern conversion pattern. 124 */ 125 public void setConversionPattern(final String conversionPattern) { 126 final String pattern = OptionConverter.convertSpecialChars(conversionPattern); 127 if (pattern == null) { 128 return; 129 } 130 final PatternParser parser = createPatternParser(this.config); 131 formatters = parser.parse(pattern, this.handleExceptions); 132 } 133 134 public String getConversionPattern() { 135 return conversionPattern; 136 } 137 138 /** 139 * PatternLayout's content format is specified by:<p/> 140 * Key: "structured" Value: "false"<p/> 141 * Key: "formatType" Value: "conversion" (format uses the keywords supported by OptionConverter)<p/> 142 * Key: "format" Value: provided "conversionPattern" param 143 * @return Map of content format keys supporting PatternLayout 144 */ 145 @Override 146 public Map<String, String> getContentFormat() 147 { 148 Map<String, String> result = new HashMap<String, String>(); 149 result.put("structured", "false"); 150 result.put("formatType", "conversion"); 151 result.put("format", conversionPattern); 152 return result; 153 } 154 155 /** 156 * Formats a logging event to a writer. 157 * 158 * 159 * @param event logging event to be formatted. 160 * @return The event formatted as a String. 161 */ 162 @Override 163 public String toSerializable(final LogEvent event) { 164 final StringBuilder buf = new StringBuilder(); 165 for (final PatternFormatter formatter : formatters) { 166 formatter.format(event, buf); 167 } 168 String str = buf.toString(); 169 if (replace != null) { 170 str = replace.format(str); 171 } 172 return str; 173 } 174 175 /** 176 * Create a PatternParser. 177 * @param config The Configuration. 178 * @return The PatternParser. 179 */ 180 public static PatternParser createPatternParser(final Configuration config) { 181 if (config == null) { 182 return new PatternParser(config, KEY, LogEventPatternConverter.class); 183 } 184 PatternParser parser = (PatternParser) config.getComponent(KEY); 185 if (parser == null) { 186 parser = new PatternParser(config, KEY, LogEventPatternConverter.class); 187 config.addComponent(KEY, parser); 188 parser = (PatternParser) config.getComponent(KEY); 189 } 190 return parser; 191 } 192 193 @Override 194 public String toString() { 195 return conversionPattern; 196 } 197 198 /** 199 * Create a pattern layout. 200 * 201 * @param pattern The pattern. If not specified, defaults to DEFAULT_CONVERSION_PATTERN. 202 * @param config The Configuration. Some Converters require access to the Interpolator. 203 * @param replace A Regex replacement String. 204 * @param charsetName The character set. 205 * @param suppressExceptions Whether or not exceptions should be suppressed in this pattern (defaults to no, which 206 * means exceptions will be written even if the pattern does not specify so). 207 * @return The PatternLayout. 208 */ 209 @PluginFactory 210 public static PatternLayout createLayout(@PluginAttr("pattern") final String pattern, 211 @PluginConfiguration final Configuration config, 212 @PluginElement("replace") final RegexReplacement replace, 213 @PluginAttr("charset") final String charsetName, 214 @PluginAttr("suppressExceptions") final String suppressExceptions) { 215 final Charset charset = Charsets.getSupportedCharset(charsetName); 216 boolean handleExceptions = suppressExceptions == null || !Boolean.parseBoolean(suppressExceptions); 217 return new PatternLayout(config, replace, pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, charset, 218 handleExceptions); 219 } 220 }