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.pattern;
018    
019    import java.lang.reflect.Method;
020    import java.lang.reflect.Modifier;
021    import java.util.ArrayList;
022    import java.util.HashMap;
023    import java.util.Iterator;
024    import java.util.List;
025    import java.util.Map;
026    
027    import org.apache.logging.log4j.Logger;
028    import org.apache.logging.log4j.core.config.Configuration;
029    import org.apache.logging.log4j.core.config.plugins.util.PluginManager;
030    import org.apache.logging.log4j.core.config.plugins.util.PluginType;
031    import org.apache.logging.log4j.status.StatusLogger;
032    import org.apache.logging.log4j.util.Strings;
033    
034    /**
035     * Most of the work of the {@link org.apache.logging.log4j.core.layout.PatternLayout} class is delegated to the
036     * PatternParser class.
037     * <p>
038     * It is this class that parses conversion patterns and creates a chained list of {@link PatternConverter
039     * PatternConverters}.
040     */
041    public final class PatternParser {
042        static final String NO_CONSOLE_NO_ANSI = "noConsoleNoAnsi";
043    
044        /**
045         * Escape character for format specifier.
046         */
047        private static final char ESCAPE_CHAR = '%';
048    
049        /**
050         * The states the parser can be in while parsing the pattern.
051         */
052        private enum ParserState {
053            /**
054             * Literal state.
055             */
056            LITERAL_STATE,
057    
058            /**
059             * In converter name state.
060             */
061            CONVERTER_STATE,
062    
063            /**
064             * Dot state.
065             */
066            DOT_STATE,
067    
068            /**
069             * Min state.
070             */
071            MIN_STATE,
072    
073            /**
074             * Max state.
075             */
076            MAX_STATE;
077        }
078    
079        private static final Logger LOGGER = StatusLogger.getLogger();
080    
081        private static final int BUF_SIZE = 32;
082    
083        private static final int DECIMAL = 10;
084    
085        private final Configuration config;
086    
087        private final Map<String, Class<PatternConverter>> converterRules;
088    
089        /**
090         * Constructor.
091         *
092         * @param converterKey
093         *            The type of converters that will be used.
094         */
095        public PatternParser(final String converterKey) {
096            this(null, converterKey, null, null);
097        }
098    
099        /**
100         * Constructor.
101         *
102         * @param config
103         *            The current Configuration.
104         * @param converterKey
105         *            The key to lookup the converters.
106         * @param expected
107         *            The expected base Class of each Converter.
108         */
109        public PatternParser(final Configuration config, final String converterKey, final Class<?> expected) {
110            this(config, converterKey, expected, null);
111        }
112    
113        /**
114         * Constructor.
115         *
116         * @param config
117         *            The current Configuration.
118         * @param converterKey
119         *            The key to lookup the converters.
120         * @param expectedClass
121         *            The expected base Class of each Converter.
122         * @param filterClass
123         *            Filter the returned plugins after calling the plugin manager.
124         */
125        public PatternParser(final Configuration config, final String converterKey, final Class<?> expectedClass,
126                final Class<?> filterClass) {
127            this.config = config;
128            final PluginManager manager = new PluginManager(converterKey);
129            manager.collectPlugins();
130            final Map<String, PluginType<?>> plugins = manager.getPlugins();
131            final Map<String, Class<PatternConverter>> converters = new HashMap<String, Class<PatternConverter>>();
132    
133            for (final PluginType<?> type : plugins.values()) {
134                try {
135                    @SuppressWarnings("unchecked")
136                    final Class<PatternConverter> clazz = (Class<PatternConverter>) type.getPluginClass();
137                    if (filterClass != null && !filterClass.isAssignableFrom(clazz)) {
138                        continue;
139                    }
140                    final ConverterKeys keys = clazz.getAnnotation(ConverterKeys.class);
141                    if (keys != null) {
142                        for (final String key : keys.value()) {
143                            converters.put(key, clazz);
144                        }
145                    }
146                } catch (final Exception ex) {
147                    LOGGER.error("Error processing plugin " + type.getElementName(), ex);
148                }
149            }
150            converterRules = converters;
151        }
152    
153        public List<PatternFormatter> parse(final String pattern) {
154            return parse(pattern, false, false);
155        }
156    
157        public List<PatternFormatter> parse(final String pattern, final boolean alwaysWriteExceptions,
158                final boolean noConsoleNoAnsi) {
159            final List<PatternFormatter> list = new ArrayList<PatternFormatter>();
160            final List<PatternConverter> converters = new ArrayList<PatternConverter>();
161            final List<FormattingInfo> fields = new ArrayList<FormattingInfo>();
162    
163            parse(pattern, converters, fields, noConsoleNoAnsi);
164    
165            final Iterator<FormattingInfo> fieldIter = fields.iterator();
166            boolean handlesThrowable = false;
167    
168            for (final PatternConverter converter : converters) {
169                LogEventPatternConverter pc;
170                if (converter instanceof LogEventPatternConverter) {
171                    pc = (LogEventPatternConverter) converter;
172                    handlesThrowable |= pc.handlesThrowable();
173                } else {
174                    pc = new LiteralPatternConverter(config, Strings.EMPTY);
175                }
176    
177                FormattingInfo field;
178                if (fieldIter.hasNext()) {
179                    field = fieldIter.next();
180                } else {
181                    field = FormattingInfo.getDefault();
182                }
183                list.add(new PatternFormatter(pc, field));
184            }
185            if (alwaysWriteExceptions && !handlesThrowable) {
186                final LogEventPatternConverter pc = ExtendedThrowablePatternConverter.newInstance(null);
187                list.add(new PatternFormatter(pc, FormattingInfo.getDefault()));
188            }
189            return list;
190        }
191    
192        /**
193         * Extract the converter identifier found at position i.
194         * <p/>
195         * After this function returns, the variable i will point to the first char after the end of the converter
196         * identifier.
197         * <p/>
198         * If i points to a char which is not a character acceptable at the start of a unicode identifier, the value null is
199         * returned.
200         *
201         * @param lastChar
202         *            last processed character.
203         * @param pattern
204         *            format string.
205         * @param i
206         *            current index into pattern format.
207         * @param convBuf
208         *            buffer to receive conversion specifier.
209         * @param currentLiteral
210         *            literal to be output in case format specifier in unrecognized.
211         * @return position in pattern after converter.
212         */
213        private static int extractConverter(final char lastChar, final String pattern, int i, final StringBuilder convBuf,
214                final StringBuilder currentLiteral) {
215            convBuf.setLength(0);
216    
217            // When this method is called, lastChar points to the first character of the
218            // conversion word. For example:
219            // For "%hello" lastChar = 'h'
220            // For "%-5hello" lastChar = 'h'
221            // System.out.println("lastchar is "+lastChar);
222            if (!Character.isUnicodeIdentifierStart(lastChar)) {
223                return i;
224            }
225    
226            convBuf.append(lastChar);
227    
228            while (i < pattern.length() && Character.isUnicodeIdentifierPart(pattern.charAt(i))) {
229                convBuf.append(pattern.charAt(i));
230                currentLiteral.append(pattern.charAt(i));
231                i++;
232            }
233    
234            return i;
235        }
236    
237        /**
238         * Extract options.
239         *
240         * @param pattern
241         *            conversion pattern.
242         * @param i
243         *            start of options.
244         * @param options
245         *            array to receive extracted options
246         * @return position in pattern after options.
247         */
248        private static int extractOptions(final String pattern, int i, final List<String> options) {
249            while (i < pattern.length() && pattern.charAt(i) == '{') {
250                final int begin = i++;
251                int end;
252                int depth = 0;
253                do {
254                    end = pattern.indexOf('}', i);
255                    if (end != -1) {
256                        final int next = pattern.indexOf("{", i);
257                        if (next != -1 && next < end) {
258                            i = end + 1;
259                            ++depth;
260                        } else if (depth > 0) {
261                            --depth;
262                        }
263                    }
264                } while (depth > 0);
265    
266                if (end == -1) {
267                    break;
268                }
269    
270                final String r = pattern.substring(begin + 1, end);
271                options.add(r);
272                i = end + 1;
273            }
274    
275            return i;
276        }
277    
278        /**
279         * Parse a format specifier.
280         *
281         * @param pattern
282         *            pattern to parse.
283         * @param patternConverters
284         *            list to receive pattern converters.
285         * @param formattingInfos
286         *            list to receive field specifiers corresponding to pattern converters.
287         * @param noConsoleNoAnsi
288         *            TODO
289         */
290        public void parse(final String pattern, final List<PatternConverter> patternConverters,
291                final List<FormattingInfo> formattingInfos, final boolean noConsoleNoAnsi) {
292            if (pattern == null) {
293                throw new NullPointerException("pattern");
294            }
295    
296            final StringBuilder currentLiteral = new StringBuilder(BUF_SIZE);
297    
298            final int patternLength = pattern.length();
299            ParserState state = ParserState.LITERAL_STATE;
300            char c;
301            int i = 0;
302            FormattingInfo formattingInfo = FormattingInfo.getDefault();
303    
304            while (i < patternLength) {
305                c = pattern.charAt(i++);
306    
307                switch (state) {
308                case LITERAL_STATE:
309    
310                    // In literal state, the last char is always a literal.
311                    if (i == patternLength) {
312                        currentLiteral.append(c);
313    
314                        continue;
315                    }
316    
317                    if (c == ESCAPE_CHAR) {
318                        // peek at the next char.
319                        switch (pattern.charAt(i)) {
320                        case ESCAPE_CHAR:
321                            currentLiteral.append(c);
322                            i++; // move pointer
323    
324                            break;
325    
326                        default:
327    
328                            if (currentLiteral.length() != 0) {
329                                patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString()));
330                                formattingInfos.add(FormattingInfo.getDefault());
331                            }
332    
333                            currentLiteral.setLength(0);
334                            currentLiteral.append(c); // append %
335                            state = ParserState.CONVERTER_STATE;
336                            formattingInfo = FormattingInfo.getDefault();
337                        }
338                    } else {
339                        currentLiteral.append(c);
340                    }
341    
342                    break;
343    
344                case CONVERTER_STATE:
345                    currentLiteral.append(c);
346    
347                    switch (c) {
348                    case '-':
349                        formattingInfo = new FormattingInfo(true, formattingInfo.getMinLength(),
350                                formattingInfo.getMaxLength());
351                        break;
352    
353                    case '.':
354                        state = ParserState.DOT_STATE;
355                        break;
356    
357                    default:
358    
359                        if (c >= '0' && c <= '9') {
360                            formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), c - '0',
361                                    formattingInfo.getMaxLength());
362                            state = ParserState.MIN_STATE;
363                        } else {
364                            i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRules,
365                                    patternConverters, formattingInfos, noConsoleNoAnsi);
366    
367                            // Next pattern is assumed to be a literal.
368                            state = ParserState.LITERAL_STATE;
369                            formattingInfo = FormattingInfo.getDefault();
370                            currentLiteral.setLength(0);
371                        }
372                    } // switch
373    
374                    break;
375    
376                case MIN_STATE:
377                    currentLiteral.append(c);
378    
379                    if (c >= '0' && c <= '9') {
380                        // Multiply the existing value and add the value of the number just encountered.
381                        formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength()
382                                * DECIMAL + c - '0', formattingInfo.getMaxLength());
383                    } else if (c == '.') {
384                        state = ParserState.DOT_STATE;
385                    } else {
386                        i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRules,
387                                patternConverters, formattingInfos, noConsoleNoAnsi);
388                        state = ParserState.LITERAL_STATE;
389                        formattingInfo = FormattingInfo.getDefault();
390                        currentLiteral.setLength(0);
391                    }
392    
393                    break;
394    
395                case DOT_STATE:
396                    currentLiteral.append(c);
397    
398                    if (c >= '0' && c <= '9') {
399                        formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
400                                c - '0');
401                        state = ParserState.MAX_STATE;
402                    } else {
403                        LOGGER.error("Error occurred in position " + i + ".\n Was expecting digit, instead got char \"" + c
404                                + "\".");
405    
406                        state = ParserState.LITERAL_STATE;
407                    }
408    
409                    break;
410    
411                case MAX_STATE:
412                    currentLiteral.append(c);
413    
414                    if (c >= '0' && c <= '9') {
415                        // Multiply the existing value and add the value of the number just encountered.
416                        formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
417                                formattingInfo.getMaxLength() * DECIMAL + c - '0');
418                    } else {
419                        i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRules,
420                                patternConverters, formattingInfos, noConsoleNoAnsi);
421                        state = ParserState.LITERAL_STATE;
422                        formattingInfo = FormattingInfo.getDefault();
423                        currentLiteral.setLength(0);
424                    }
425    
426                    break;
427                } // switch
428            }
429    
430            // while
431            if (currentLiteral.length() != 0) {
432                patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString()));
433                formattingInfos.add(FormattingInfo.getDefault());
434            }
435        }
436    
437        /**
438         * Creates a new PatternConverter.
439         *
440         * @param converterId
441         *            converterId.
442         * @param currentLiteral
443         *            literal to be used if converter is unrecognized or following converter if converterId contains extra
444         *            characters.
445         * @param rules
446         *            map of stock pattern converters keyed by format specifier.
447         * @param options
448         *            converter options.
449         * @param noConsoleNoAnsi TODO
450         * @return converter or null.
451         */
452        private PatternConverter createConverter(final String converterId, final StringBuilder currentLiteral,
453                final Map<String, Class<PatternConverter>> rules, final List<String> options, final boolean noConsoleNoAnsi) {
454            String converterName = converterId;
455            Class<PatternConverter> converterClass = null;
456    
457            if (rules == null) {
458                LOGGER.error("Null rules for [" + converterId + ']');
459                return null;
460            }
461            for (int i = converterId.length(); i > 0 && converterClass == null; i--) {
462                converterName = converterName.substring(0, i);
463                converterClass = rules.get(converterName);
464            }
465    
466            if (converterClass == null) {
467                LOGGER.error("Unrecognized format specifier [" + converterId + ']');
468                return null;
469            }
470    
471            if (AnsiConverter.class.isAssignableFrom(converterClass)) {
472                options.add(NO_CONSOLE_NO_ANSI + '=' + noConsoleNoAnsi);
473            }
474            // Work around the regression bug in Class.getDeclaredMethods() in Oracle Java in version > 1.6.0_17:
475            // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6815786
476            final Method[] methods = converterClass.getDeclaredMethods();
477            Method newInstanceMethod = null;
478            for (final Method method : methods) {
479                if (Modifier.isStatic(method.getModifiers()) && method.getDeclaringClass().equals(converterClass)
480                        && method.getName().equals("newInstance")) {
481                    if (newInstanceMethod == null) {
482                        newInstanceMethod = method;
483                    } else if (method.getReturnType().equals(newInstanceMethod.getReturnType())) {
484                        LOGGER.error("Class " + converterClass + " cannot contain multiple static newInstance methods");
485                        return null;
486                    }
487                }
488            }
489            if (newInstanceMethod == null) {
490                LOGGER.error("Class " + converterClass + " does not contain a static newInstance method");
491                return null;
492            }
493    
494            final Class<?>[] parmTypes = newInstanceMethod.getParameterTypes();
495            final Object[] parms = parmTypes.length > 0 ? new Object[parmTypes.length] : null;
496    
497            if (parms != null) {
498                int i = 0;
499                boolean errors = false;
500                for (final Class<?> clazz : parmTypes) {
501                    if (clazz.isArray() && clazz.getName().equals("[Ljava.lang.String;")) {
502                        final String[] optionsArray = options.toArray(new String[options.size()]);
503                        parms[i] = optionsArray;
504                    } else if (clazz.isAssignableFrom(Configuration.class)) {
505                        parms[i] = config;
506                    } else {
507                        LOGGER.error("Unknown parameter type " + clazz.getName() + " for static newInstance method of "
508                                + converterClass.getName());
509                        errors = true;
510                    }
511                    ++i;
512                }
513                if (errors) {
514                    return null;
515                }
516            }
517    
518            try {
519                final Object newObj = newInstanceMethod.invoke(null, parms);
520    
521                if (newObj instanceof PatternConverter) {
522                    currentLiteral.delete(0, currentLiteral.length() - (converterId.length() - converterName.length()));
523    
524                    return (PatternConverter) newObj;
525                }
526                LOGGER.warn("Class " + converterClass.getName() + " does not extend PatternConverter.");
527            } catch (final Exception ex) {
528                LOGGER.error("Error creating converter for " + converterId, ex);
529            }
530    
531            return null;
532        }
533    
534        /**
535         * Processes a format specifier sequence.
536         *
537         * @param c
538         *            initial character of format specifier.
539         * @param pattern
540         *            conversion pattern
541         * @param i
542         *            current position in conversion pattern.
543         * @param currentLiteral
544         *            current literal.
545         * @param formattingInfo
546         *            current field specifier.
547         * @param rules
548         *            map of stock pattern converters keyed by format specifier.
549         * @param patternConverters
550         *            list to receive parsed pattern converter.
551         * @param formattingInfos
552         *            list to receive corresponding field specifier.
553         * @param noConsoleNoAnsi
554         *            TODO
555         * @return position after format specifier sequence.
556         */
557        private int finalizeConverter(final char c, final String pattern, int i, final StringBuilder currentLiteral,
558                final FormattingInfo formattingInfo, final Map<String, Class<PatternConverter>> rules,
559                final List<PatternConverter> patternConverters, final List<FormattingInfo> formattingInfos,
560                final boolean noConsoleNoAnsi) {
561            final StringBuilder convBuf = new StringBuilder();
562            i = extractConverter(c, pattern, i, convBuf, currentLiteral);
563    
564            final String converterId = convBuf.toString();
565    
566            final List<String> options = new ArrayList<String>();
567            i = extractOptions(pattern, i, options);
568    
569            final PatternConverter pc = createConverter(converterId, currentLiteral, rules, options, noConsoleNoAnsi);
570    
571            if (pc == null) {
572                StringBuilder msg;
573    
574                if (Strings.isEmpty(converterId)) {
575                    msg = new StringBuilder("Empty conversion specifier starting at position ");
576                } else {
577                    msg = new StringBuilder("Unrecognized conversion specifier [");
578                    msg.append(converterId);
579                    msg.append("] starting at position ");
580                }
581    
582                msg.append(Integer.toString(i));
583                msg.append(" in conversion pattern.");
584    
585                LOGGER.error(msg.toString());
586    
587                patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString()));
588                formattingInfos.add(FormattingInfo.getDefault());
589            } else {
590                patternConverters.add(pc);
591                formattingInfos.add(formattingInfo);
592    
593                if (currentLiteral.length() > 0) {
594                    patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString()));
595                    formattingInfos.add(FormattingInfo.getDefault());
596                }
597            }
598    
599            currentLiteral.setLength(0);
600    
601            return i;
602        }
603    }