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 java.util.HashMap;
020 import java.util.Map;
021 import org.apache.logging.log4j.core.LogEvent;
022 import org.apache.logging.log4j.core.config.Configuration;
023 import org.apache.logging.log4j.core.config.plugins.Plugin;
024 import org.apache.logging.log4j.core.config.plugins.PluginAttr;
025 import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
026 import org.apache.logging.log4j.core.config.plugins.PluginElement;
027 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
028 import org.apache.logging.log4j.core.helpers.Charsets;
029 import org.apache.logging.log4j.core.helpers.OptionConverter;
030 import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
031 import org.apache.logging.log4j.core.pattern.PatternFormatter;
032 import org.apache.logging.log4j.core.pattern.PatternParser;
033 import org.apache.logging.log4j.core.pattern.RegexReplacement;
034
035 import java.nio.charset.Charset;
036 import java.util.List;
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 /**
096 * Constructs a EnhancedPatternLayout using the supplied conversion pattern.
097 *
098 * @param config The Configuration.
099 * @param replace The regular expression to match.
100 * @param pattern conversion pattern.
101 * @param charset The character set.
102 */
103 private PatternLayout(final Configuration config, final RegexReplacement replace, final String pattern,
104 final Charset charset) {
105 super(charset);
106 this.replace = replace;
107 this.conversionPattern = pattern;
108 this.config = config;
109 final PatternParser parser = createPatternParser(config);
110 formatters = parser.parse(pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, true);
111 }
112
113 /**
114 * Set the <b>ConversionPattern</b> option. This is the string which
115 * controls formatting and consists of a mix of literal content and
116 * conversion specifiers.
117 *
118 * @param conversionPattern conversion pattern.
119 */
120 public void setConversionPattern(final String conversionPattern) {
121 final String pattern = OptionConverter.convertSpecialChars(conversionPattern);
122 if (pattern == null) {
123 return;
124 }
125 final PatternParser parser = createPatternParser(this.config);
126 formatters = parser.parse(pattern);
127 }
128
129 public String getConversionPattern() {
130 return conversionPattern;
131 }
132
133 /**
134 * PatternLayout's content format is specified by:<p/>
135 * Key: "structured" Value: "false"<p/>
136 * Key: "formatType" Value: "conversion" (format uses the keywords supported by OptionConverter)<p/>
137 * Key: "format" Value: provided "conversionPattern" param
138 * @return Map of content format keys supporting PatternLayout
139 */
140 public Map<String, String> getContentFormat()
141 {
142 Map<String, String> result = new HashMap<String, String>();
143 result.put("structured", "false");
144 result.put("formatType", "conversion");
145 result.put("format", conversionPattern);
146 return result;
147 }
148
149 /**
150 * Formats a logging event to a writer.
151 *
152 *
153 * @param event logging event to be formatted.
154 * @return The event formatted as a String.
155 */
156 public String toSerializable(final LogEvent event) {
157 final StringBuilder buf = new StringBuilder();
158 for (final PatternFormatter formatter : formatters) {
159 formatter.format(event, buf);
160 }
161 String str = buf.toString();
162 if (replace != null) {
163 str = replace.format(str);
164 }
165 return str;
166 }
167
168 /**
169 * Create a PatternParser.
170 * @param config The Configuration.
171 * @return The PatternParser.
172 */
173 public static PatternParser createPatternParser(final Configuration config) {
174 if (config == null) {
175 return new PatternParser(config, KEY, LogEventPatternConverter.class);
176 }
177 PatternParser parser = (PatternParser) config.getComponent(KEY);
178 if (parser == null) {
179 parser = new PatternParser(config, KEY, LogEventPatternConverter.class);
180 config.addComponent(KEY, parser);
181 parser = (PatternParser) config.getComponent(KEY);
182 }
183 return parser;
184 }
185
186 @Override
187 public String toString() {
188 return conversionPattern;
189 }
190
191 /**
192 * Create a pattern layout.
193 * @param pattern The pattern. If not specified, defaults to DEFAULT_CONVERSION_PATTERN.
194 * @param config The Configuration. Some Converters require access to the Interpolator.
195 * @param replace A Regex replacement String.
196 * @param charsetName The character set.
197 * @return The PatternLayout.
198 */
199 @PluginFactory
200 public static PatternLayout createLayout(@PluginAttr("pattern") final String pattern,
201 @PluginConfiguration final Configuration config,
202 @PluginElement("replace") final RegexReplacement replace,
203 @PluginAttr("charset") final String charsetName) {
204 final Charset charset = Charsets.getSupportedCharset(charsetName);
205 return new PatternLayout(config, replace, pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, charset);
206 }
207 }