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.nio.charset.Charset;
020    import java.util.HashMap;
021    import java.util.List;
022    import java.util.Map;
023    
024    import org.apache.logging.log4j.core.Layout;
025    import org.apache.logging.log4j.core.LogEvent;
026    import org.apache.logging.log4j.core.config.Configuration;
027    import org.apache.logging.log4j.core.config.DefaultConfiguration;
028    import org.apache.logging.log4j.core.config.Node;
029    import org.apache.logging.log4j.core.config.plugins.Plugin;
030    import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
031    import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
032    import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
033    import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
034    import org.apache.logging.log4j.core.config.plugins.PluginElement;
035    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
036    import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
037    import org.apache.logging.log4j.core.pattern.PatternFormatter;
038    import org.apache.logging.log4j.core.pattern.PatternParser;
039    import org.apache.logging.log4j.core.pattern.RegexReplacement;
040    
041    /**
042     * A flexible layout configurable with pattern string.
043     * <p>
044     * The goal of this class is to {@link org.apache.logging.log4j.core.Layout#toByteArray format} a {@link LogEvent} and
045     * return the results. The format of the result depends on the <em>conversion pattern</em>.
046     * </p>
047     * <p>
048     * The conversion pattern is closely related to the conversion pattern of the printf function in C. A conversion pattern
049     * is composed of literal text and format control expressions called <em>conversion specifiers</em>.
050     * </p>
051     * <p>
052     * See the Log4j Manual for details on the supported pattern converters.
053     * </p>
054     */
055    @Plugin(name = "PatternLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
056    public final class PatternLayout extends AbstractStringLayout {
057    
058        private static final long serialVersionUID = 1L;
059    
060        /**
061         * Default pattern string for log output. Currently set to the
062         * string <b>"%m%n"</b> which just prints the application supplied
063         * message.
064         */
065        public static final String DEFAULT_CONVERSION_PATTERN = "%m%n";
066    
067        /**
068         * A conversion pattern equivalent to the TTCCCLayout.
069         * Current value is <b>%r [%t] %p %c %x - %m%n</b>.
070         */
071        public static final String TTCC_CONVERSION_PATTERN =
072            "%r [%t] %p %c %x - %m%n";
073    
074        /**
075         * A simple pattern.
076         * Current value is <b>%d [%t] %p %c - %m%n</b>.
077         */
078        public static final String SIMPLE_CONVERSION_PATTERN =
079            "%d [%t] %p %c - %m%n";
080    
081        /** Key to identify pattern converters. */
082        public static final String KEY = "Converter";
083    
084        /**
085         * Initial converter for pattern.
086         */
087        private final List<PatternFormatter> formatters;
088    
089        /**
090         * Conversion pattern.
091         */
092        private final String conversionPattern;
093    
094    
095        /**
096         * The current Configuration.
097         */
098        private final Configuration config;
099    
100        private final RegexReplacement replace;
101    
102        private final boolean alwaysWriteExceptions;
103    
104        private final boolean noConsoleNoAnsi;
105    
106        /**
107         * Constructs a EnhancedPatternLayout using the supplied conversion pattern.
108         *
109         * @param config The Configuration.
110         * @param replace The regular expression to match.
111         * @param pattern conversion pattern.
112         * @param charset The character set.
113         * @param alwaysWriteExceptions Whether or not exceptions should always be handled in this pattern (if {@code true},
114         *                         exceptions will be written even if the pattern does not specify so).
115         * @param noConsoleNoAnsi
116         *            If {@code "true"} (default) and {@link System#console()} is null, do not output ANSI escape codes
117         * @param header
118         */
119        private PatternLayout(final Configuration config, final RegexReplacement replace, final String pattern,
120                              final Charset charset, final boolean alwaysWriteExceptions, final boolean noConsoleNoAnsi,
121                              final String header, final String footer) {
122            super(charset, toBytes(header, charset), toBytes(footer, charset));
123            this.replace = replace;
124            this.conversionPattern = pattern;
125            this.config = config;
126            this.alwaysWriteExceptions = alwaysWriteExceptions;
127            this.noConsoleNoAnsi = noConsoleNoAnsi;
128            final PatternParser parser = createPatternParser(config);
129            this.formatters = parser.parse(pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, this.alwaysWriteExceptions, this.noConsoleNoAnsi);
130        }
131    
132        private static byte[] toBytes(final String str, final Charset charset) {
133            if (str != null) {
134                return str.getBytes(charset != null ? charset : Charset.defaultCharset());
135            }
136            return null;
137        }
138    
139        private byte[] strSubstitutorReplace(final byte... b) {
140            if (b != null && config != null) {
141                return getBytes(config.getStrSubstitutor().replace(new String(b, getCharset())));
142            }
143            return b;
144        }
145    
146        @Override
147        public byte[] getHeader() {
148            return strSubstitutorReplace(super.getHeader());
149        }
150    
151        @Override
152        public byte[] getFooter() {
153            return strSubstitutorReplace(super.getFooter());
154        }
155    
156        /**
157         * Gets the conversion pattern.
158         *
159         * @return the conversion pattern.
160         */
161        public String getConversionPattern() {
162            return conversionPattern;
163        }
164    
165        /**
166         * Gets this PatternLayout's content format. Specified by:
167         * <ul>
168         * <li>Key: "structured" Value: "false"</li>
169         * <li>Key: "formatType" Value: "conversion" (format uses the keywords supported by OptionConverter)</li>
170         * <li>Key: "format" Value: provided "conversionPattern" param</li>
171         * </ul>
172         * 
173         * @return Map of content format keys supporting PatternLayout
174         */
175        @Override
176        public Map<String, String> getContentFormat()
177        {
178            final Map<String, String> result = new HashMap<String, String>();
179            result.put("structured", "false");
180            result.put("formatType", "conversion");
181            result.put("format", conversionPattern);
182            return result;
183        }
184    
185        /**
186         * Formats a logging event to a writer.
187         *
188         *
189         * @param event logging event to be formatted.
190         * @return The event formatted as a String.
191         */
192        @Override
193        public String toSerializable(final LogEvent event) {
194            final StringBuilder buf = new StringBuilder();
195            for (final PatternFormatter formatter : formatters) {
196                formatter.format(event, buf);
197            }
198            String str = buf.toString();
199            if (replace != null) {
200                str = replace.format(str);
201            }
202            return str;
203        }
204    
205        /**
206         * Create a PatternParser.
207         * @param config The Configuration.
208         * @return The PatternParser.
209         */
210        public static PatternParser createPatternParser(final Configuration config) {
211            if (config == null) {
212                return new PatternParser(config, KEY, LogEventPatternConverter.class);
213            }
214            PatternParser parser = config.getComponent(KEY);
215            if (parser == null) {
216                parser = new PatternParser(config, KEY, LogEventPatternConverter.class);
217                config.addComponent(KEY, parser);
218                parser = (PatternParser) config.getComponent(KEY);
219            }
220            return parser;
221        }
222    
223        @Override
224        public String toString() {
225            return conversionPattern;
226        }
227    
228        /**
229         * Create a pattern layout.
230         *
231         * @param pattern
232         *        The pattern. If not specified, defaults to DEFAULT_CONVERSION_PATTERN.
233         * @param config
234         *        The Configuration. Some Converters require access to the Interpolator.
235         * @param replace
236         *        A Regex replacement String.
237         * @param charset
238         *        The character set.
239         * @param alwaysWriteExceptions
240         *        If {@code "true"} (default) exceptions are always written even if the pattern contains no exception tokens.
241         * @param noConsoleNoAnsi
242         *        If {@code "true"} (default is false) and {@link System#console()} is null, do not output ANSI escape codes
243         * @param header
244         *        The footer to place at the top of the document, once.
245         * @param footer
246         *        The footer to place at the bottom of the document, once.
247         * @return The PatternLayout.
248         */
249        @PluginFactory
250        public static PatternLayout createLayout(
251                @PluginAttribute(value = "pattern", defaultString = DEFAULT_CONVERSION_PATTERN) final String pattern,
252                @PluginConfiguration final Configuration config,
253                @PluginElement("Replace") final RegexReplacement replace,
254                @PluginAttribute(value = "charset", defaultString = "UTF-8") final Charset charset,
255                @PluginAttribute(value = "alwaysWriteExceptions", defaultBoolean = true) final boolean alwaysWriteExceptions,
256                @PluginAttribute(value = "noConsoleNoAnsi", defaultBoolean = false) final boolean noConsoleNoAnsi,
257                @PluginAttribute("header") final String header,
258                @PluginAttribute("footer") final String footer) {
259            return newBuilder()
260                .withPattern(pattern)
261                .withConfiguration(config)
262                .withRegexReplacement(replace)
263                .withCharset(charset)
264                .withAlwaysWriteExceptions(alwaysWriteExceptions)
265                .withNoConsoleNoAnsi(noConsoleNoAnsi)
266                .withHeader(header)
267                .withFooter(footer)
268                .build();
269        }
270    
271        /**
272         * Creates a PatternLayout using the default options. These options include using UTF-8, the default conversion
273         * pattern, exceptions being written, and with ANSI escape codes.
274         *
275         * @return the PatternLayout.
276         * @see #DEFAULT_CONVERSION_PATTERN Default conversion pattern
277         */
278        public static PatternLayout createDefaultLayout() {
279            return newBuilder().build();
280        }
281    
282        /**
283         * Creates a builder for a custom PatternLayout.
284         * @return a PatternLayout builder.
285         */
286        @PluginBuilderFactory
287        public static Builder newBuilder() {
288            return new Builder();
289        }
290    
291        /**
292         * Custom PatternLayout builder. Use the {@link PatternLayout#newBuilder() builder factory method} to create this.
293         */
294        public static class Builder implements org.apache.logging.log4j.core.util.Builder<PatternLayout> {
295    
296            // FIXME: it seems rather redundant to repeat default values (same goes for field names)
297            // perhaps introduce a @PluginBuilderAttribute that has no values of its own and uses reflection?
298    
299            @PluginBuilderAttribute
300            private String pattern = PatternLayout.DEFAULT_CONVERSION_PATTERN;
301    
302            @PluginConfiguration
303            private Configuration configuration = null;
304    
305            @PluginElement("Replace")
306            private RegexReplacement regexReplacement = null;
307    
308            // LOG4J2-783 use platform default by default
309            @PluginBuilderAttribute
310            private Charset charset = Charset.defaultCharset();
311    
312            @PluginBuilderAttribute
313            private boolean alwaysWriteExceptions = true;
314    
315            @PluginBuilderAttribute
316            private boolean noConsoleNoAnsi = false;
317    
318            @PluginBuilderAttribute
319            private String header = null;
320    
321            @PluginBuilderAttribute
322            private String footer = null;
323    
324            private Builder() {
325            }
326    
327            // TODO: move javadocs from PluginFactory to here
328    
329            public Builder withPattern(final String pattern) {
330                this.pattern = pattern;
331                return this;
332            }
333    
334    
335            public Builder withConfiguration(final Configuration configuration) {
336                this.configuration = configuration;
337                return this;
338            }
339    
340            public Builder withRegexReplacement(final RegexReplacement regexReplacement) {
341                this.regexReplacement = regexReplacement;
342                return this;
343            }
344    
345            public Builder withCharset(final Charset charset) {
346                this.charset = charset;
347                return this;
348            }
349    
350            public Builder withAlwaysWriteExceptions(final boolean alwaysWriteExceptions) {
351                this.alwaysWriteExceptions = alwaysWriteExceptions;
352                return this;
353            }
354    
355            public Builder withNoConsoleNoAnsi(final boolean noConsoleNoAnsi) {
356                this.noConsoleNoAnsi = noConsoleNoAnsi;
357                return this;
358            }
359    
360            public Builder withHeader(final String header) {
361                this.header = header;
362                return this;
363            }
364    
365            public Builder withFooter(final String footer) {
366                this.footer = footer;
367                return this;
368            }
369    
370            @Override
371            public PatternLayout build() {
372                // fall back to DefaultConfiguration
373                if (configuration == null) {
374                    configuration = new DefaultConfiguration();
375                }
376                return new PatternLayout(configuration, regexReplacement, pattern, charset, alwaysWriteExceptions,
377                    noConsoleNoAnsi, header, footer);
378            }
379        }
380    }