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 */
017package org.apache.logging.log4j.core.pattern;
018
019import java.lang.reflect.Method;
020import java.lang.reflect.Modifier;
021import java.util.ArrayList;
022import java.util.Iterator;
023import java.util.LinkedHashMap;
024import java.util.List;
025import java.util.Map;
026import java.util.Objects;
027
028import org.apache.logging.log4j.Logger;
029import org.apache.logging.log4j.core.config.Configuration;
030import org.apache.logging.log4j.core.config.plugins.util.PluginManager;
031import org.apache.logging.log4j.core.config.plugins.util.PluginType;
032import org.apache.logging.log4j.core.util.SystemNanoClock;
033import org.apache.logging.log4j.status.StatusLogger;
034import org.apache.logging.log4j.util.Strings;
035
036/**
037 * Most of the work of the {@link org.apache.logging.log4j.core.layout.PatternLayout} class is delegated to the
038 * PatternParser class.
039 * <p>
040 * It is this class that parses conversion patterns and creates a chained list of {@link PatternConverter
041 * PatternConverters}.
042 */
043public final class PatternParser {
044    static final String NO_CONSOLE_NO_ANSI = "noConsoleNoAnsi";
045
046    /**
047     * Escape character for format specifier.
048     */
049    private static final char ESCAPE_CHAR = '%';
050
051    /**
052     * The states the parser can be in while parsing the pattern.
053     */
054    private enum ParserState {
055        /**
056         * Literal state.
057         */
058        LITERAL_STATE,
059
060        /**
061         * In converter name state.
062         */
063        CONVERTER_STATE,
064
065        /**
066         * Dot state.
067         */
068        DOT_STATE,
069
070        /**
071         * Min state.
072         */
073        MIN_STATE,
074
075        /**
076         * Max state.
077         */
078        MAX_STATE;
079    }
080
081    private static final Logger LOGGER = StatusLogger.getLogger();
082
083    private static final int BUF_SIZE = 32;
084
085    private static final int DECIMAL = 10;
086
087    private final Configuration config;
088
089    private final Map<String, Class<PatternConverter>> converterRules;
090
091    /**
092     * Constructor.
093     *
094     * @param converterKey
095     *            The type of converters that will be used.
096     */
097    public PatternParser(final String converterKey) {
098        this(null, converterKey, null, null);
099    }
100
101    /**
102     * Constructor.
103     *
104     * @param config
105     *            The current Configuration.
106     * @param converterKey
107     *            The key to lookup the converters.
108     * @param expected
109     *            The expected base Class of each Converter.
110     */
111    public PatternParser(final Configuration config, final String converterKey, final Class<?> expected) {
112        this(config, converterKey, expected, null);
113    }
114
115    /**
116     * Constructor.
117     *
118     * @param config
119     *            The current Configuration.
120     * @param converterKey
121     *            The key to lookup the converters.
122     * @param expectedClass
123     *            The expected base Class of each Converter.
124     * @param filterClass
125     *            Filter the returned plugins after calling the plugin manager.
126     */
127    public PatternParser(final Configuration config, final String converterKey, final Class<?> expectedClass,
128            final Class<?> filterClass) {
129        this.config = config;
130        final PluginManager manager = new PluginManager(converterKey);
131        manager.collectPlugins(config == null ? null : config.getPluginPackages());
132        final Map<String, PluginType<?>> plugins = manager.getPlugins();
133        final Map<String, Class<PatternConverter>> converters = new LinkedHashMap<>();
134
135        for (final PluginType<?> type : plugins.values()) {
136            try {
137                @SuppressWarnings("unchecked")
138                final Class<PatternConverter> clazz = (Class<PatternConverter>) type.getPluginClass();
139                if (filterClass != null && !filterClass.isAssignableFrom(clazz)) {
140                    continue;
141                }
142                final ConverterKeys keys = clazz.getAnnotation(ConverterKeys.class);
143                if (keys != null) {
144                    for (final String key : keys.value()) {
145                        if (converters.containsKey(key)) {
146                            LOGGER.warn("Converter key '{}' is already mapped to '{}'. " +
147                                    "Sorry, Dave, I can't let you do that! Ignoring plugin [{}].",
148                                key, converters.get(key), clazz);
149                        } else {
150                            converters.put(key, clazz);
151                        }
152                    }
153                }
154            } catch (final Exception ex) {
155                LOGGER.error("Error processing plugin " + type.getElementName(), ex);
156            }
157        }
158        converterRules = converters;
159    }
160
161    public List<PatternFormatter> parse(final String pattern) {
162        return parse(pattern, false, false);
163    }
164
165    public List<PatternFormatter> parse(final String pattern, final boolean alwaysWriteExceptions,
166            final boolean noConsoleNoAnsi) {
167        final List<PatternFormatter> list = new ArrayList<>();
168        final List<PatternConverter> converters = new ArrayList<>();
169        final List<FormattingInfo> fields = new ArrayList<>();
170
171        parse(pattern, converters, fields, noConsoleNoAnsi, true);
172
173        final Iterator<FormattingInfo> fieldIter = fields.iterator();
174        boolean handlesThrowable = false;
175
176        for (final PatternConverter converter : converters) {
177            if (converter instanceof NanoTimePatternConverter) {
178                // LOG4J2-1074 Switch to actual clock if nanosecond timestamps are required in config.
179                // LOG4J2-1248 set config nanoclock
180                if (config != null) {
181                    config.setNanoClock(new SystemNanoClock());
182                }
183            }
184            LogEventPatternConverter pc;
185            if (converter instanceof LogEventPatternConverter) {
186                pc = (LogEventPatternConverter) converter;
187                handlesThrowable |= pc.handlesThrowable();
188            } else {
189                pc = new LiteralPatternConverter(config, Strings.EMPTY, true);
190            }
191
192            FormattingInfo field;
193            if (fieldIter.hasNext()) {
194                field = fieldIter.next();
195            } else {
196                field = FormattingInfo.getDefault();
197            }
198            list.add(new PatternFormatter(pc, field));
199        }
200        if (alwaysWriteExceptions && !handlesThrowable) {
201            final LogEventPatternConverter pc = ExtendedThrowablePatternConverter.newInstance(null);
202            list.add(new PatternFormatter(pc, FormattingInfo.getDefault()));
203        }
204        return list;
205    }
206
207    /**
208     * Extracts the converter identifier found at the given start position.
209     * <p>
210     * After this function returns, the variable i will point to the first char after the end of the converter
211     * identifier.
212     * </p>
213     * <p>
214     * If i points to a char which is not a character acceptable at the start of a unicode identifier, the value null is
215     * returned.
216     * </p>
217     *
218     * @param lastChar
219     *        last processed character.
220     * @param pattern
221     *        format string.
222     * @param start
223     *        current index into pattern format.
224     * @param convBuf
225     *        buffer to receive conversion specifier.
226     * @param currentLiteral
227     *        literal to be output in case format specifier in unrecognized.
228     * @return position in pattern after converter.
229     */
230    private static int extractConverter(final char lastChar, final String pattern, final int start,
231            final StringBuilder convBuf, final StringBuilder currentLiteral) {
232        int i = start;
233        convBuf.setLength(0);
234
235        // When this method is called, lastChar points to the first character of the
236        // conversion word. For example:
237        // For "%hello" lastChar = 'h'
238        // For "%-5hello" lastChar = 'h'
239        // System.out.println("lastchar is "+lastChar);
240        if (!Character.isUnicodeIdentifierStart(lastChar)) {
241            return i;
242        }
243
244        convBuf.append(lastChar);
245
246        while (i < pattern.length() && Character.isUnicodeIdentifierPart(pattern.charAt(i))) {
247            convBuf.append(pattern.charAt(i));
248            currentLiteral.append(pattern.charAt(i));
249            i++;
250        }
251
252        return i;
253    }
254
255    /**
256     * Extract options.
257     *
258     * @param pattern
259     *            conversion pattern.
260     * @param start
261     *            start of options.
262     * @param options
263     *            array to receive extracted options
264     * @return position in pattern after options.
265     */
266    private static int extractOptions(final String pattern, final int start, final List<String> options) {
267        int i = start;
268        while (i < pattern.length() && pattern.charAt(i) == '{') {
269            final int begin = i++;
270            int end;
271            int depth = 0;
272            do {
273                end = pattern.indexOf('}', i);
274                if (end == -1) {
275                    break;
276                }
277                final int next = pattern.indexOf("{", i);
278                if (next != -1 && next < end) {
279                    i = end + 1;
280                    ++depth;
281                } else if (depth > 0) {
282                    --depth;
283                }
284            } while (depth > 0);
285
286            if (end == -1) {
287                break;
288            }
289
290            final String r = pattern.substring(begin + 1, end);
291            options.add(r);
292            i = end + 1;
293        }
294
295        return i;
296    }
297
298    /**
299     * Parse a format specifier.
300     *
301     * @param pattern
302     *            pattern to parse.
303     * @param patternConverters
304     *            list to receive pattern converters.
305     * @param formattingInfos
306     *            list to receive field specifiers corresponding to pattern converters.
307     * @param noConsoleNoAnsi
308     *            TODO
309     * @param convertBackslashes if {@code true}, backslash characters are treated as escape characters and character
310     *            sequences like "\" followed by "t" (backslash+t) are converted to special characters like '\t' (tab).
311     */
312    public void parse(final String pattern, final List<PatternConverter> patternConverters,
313            final List<FormattingInfo> formattingInfos, final boolean noConsoleNoAnsi,
314            final boolean convertBackslashes) {
315        Objects.requireNonNull(pattern, "pattern");
316
317        final StringBuilder currentLiteral = new StringBuilder(BUF_SIZE);
318
319        final int patternLength = pattern.length();
320        ParserState state = ParserState.LITERAL_STATE;
321        char c;
322        int i = 0;
323        FormattingInfo formattingInfo = FormattingInfo.getDefault();
324
325        while (i < patternLength) {
326            c = pattern.charAt(i++);
327
328            switch (state) {
329            case LITERAL_STATE:
330
331                // In literal state, the last char is always a literal.
332                if (i == patternLength) {
333                    currentLiteral.append(c);
334
335                    continue;
336                }
337
338                if (c == ESCAPE_CHAR) {
339                    // peek at the next char.
340                    switch (pattern.charAt(i)) {
341                    case ESCAPE_CHAR:
342                        currentLiteral.append(c);
343                        i++; // move pointer
344
345                        break;
346
347                    default:
348
349                        if (currentLiteral.length() != 0) {
350                            patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString(),
351                                    convertBackslashes));
352                            formattingInfos.add(FormattingInfo.getDefault());
353                        }
354
355                        currentLiteral.setLength(0);
356                        currentLiteral.append(c); // append %
357                        state = ParserState.CONVERTER_STATE;
358                        formattingInfo = FormattingInfo.getDefault();
359                    }
360                } else {
361                    currentLiteral.append(c);
362                }
363
364                break;
365
366            case CONVERTER_STATE:
367                currentLiteral.append(c);
368
369                switch (c) {
370                case '-':
371                    formattingInfo = new FormattingInfo(true, formattingInfo.getMinLength(),
372                            formattingInfo.getMaxLength(), formattingInfo.isLeftTruncate());
373                    break;
374
375                case '.':
376                    state = ParserState.DOT_STATE;
377                    break;
378
379                default:
380
381                    if (c >= '0' && c <= '9') {
382                        formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), c - '0',
383                                formattingInfo.getMaxLength(), formattingInfo.isLeftTruncate());
384                        state = ParserState.MIN_STATE;
385                    } else {
386                        i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRules,
387                                patternConverters, formattingInfos, noConsoleNoAnsi, convertBackslashes);
388
389                        // Next pattern is assumed to be a literal.
390                        state = ParserState.LITERAL_STATE;
391                        formattingInfo = FormattingInfo.getDefault();
392                        currentLiteral.setLength(0);
393                    }
394                } // switch
395
396                break;
397
398            case MIN_STATE:
399                currentLiteral.append(c);
400
401                if (c >= '0' && c <= '9') {
402                    // Multiply the existing value and add the value of the number just encountered.
403                    formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength()
404                            * DECIMAL + c - '0', formattingInfo.getMaxLength(), formattingInfo.isLeftTruncate());
405                } else if (c == '.') {
406                    state = ParserState.DOT_STATE;
407                } else {
408                    i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRules,
409                            patternConverters, formattingInfos, noConsoleNoAnsi, convertBackslashes);
410                    state = ParserState.LITERAL_STATE;
411                    formattingInfo = FormattingInfo.getDefault();
412                    currentLiteral.setLength(0);
413                }
414
415                break;
416
417            case DOT_STATE:
418                currentLiteral.append(c);
419                switch (c) {
420                case '-':
421                    formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
422                            formattingInfo.getMaxLength(),false);
423                    break;
424
425                default:
426
427                        if (c >= '0' && c <= '9') {
428                            formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
429                                    c - '0', formattingInfo.isLeftTruncate());
430                            state = ParserState.MAX_STATE;
431                        } else {
432                            LOGGER.error("Error occurred in position " + i + ".\n Was expecting digit, instead got char \"" + c
433                                    + "\".");
434
435                            state = ParserState.LITERAL_STATE;
436                        }
437                }
438
439                break;
440
441            case MAX_STATE:
442                currentLiteral.append(c);
443
444                if (c >= '0' && c <= '9') {
445                    // Multiply the existing value and add the value of the number just encountered.
446                    formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
447                            formattingInfo.getMaxLength() * DECIMAL + c - '0', formattingInfo.isLeftTruncate());
448                } else {
449                    i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRules,
450                            patternConverters, formattingInfos, noConsoleNoAnsi, convertBackslashes);
451                    state = ParserState.LITERAL_STATE;
452                    formattingInfo = FormattingInfo.getDefault();
453                    currentLiteral.setLength(0);
454                }
455
456                break;
457            } // switch
458        }
459
460        // while
461        if (currentLiteral.length() != 0) {
462            patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString(), convertBackslashes));
463            formattingInfos.add(FormattingInfo.getDefault());
464        }
465    }
466
467    /**
468     * Creates a new PatternConverter.
469     *
470     * @param converterId
471     *            converterId.
472     * @param currentLiteral
473     *            literal to be used if converter is unrecognized or following converter if converterId contains extra
474     *            characters.
475     * @param rules
476     *            map of stock pattern converters keyed by format specifier.
477     * @param options
478     *            converter options.
479     * @param noConsoleNoAnsi TODO
480     * @return converter or null.
481     */
482    private PatternConverter createConverter(final String converterId, final StringBuilder currentLiteral,
483            final Map<String, Class<PatternConverter>> rules, final List<String> options, final boolean noConsoleNoAnsi) {
484        String converterName = converterId;
485        Class<PatternConverter> converterClass = null;
486
487        if (rules == null) {
488            LOGGER.error("Null rules for [" + converterId + ']');
489            return null;
490        }
491        for (int i = converterId.length(); i > 0 && converterClass == null; i--) {
492            converterName = converterName.substring(0, i);
493            converterClass = rules.get(converterName);
494        }
495
496        if (converterClass == null) {
497            LOGGER.error("Unrecognized format specifier [" + converterId + ']');
498            return null;
499        }
500
501        if (AnsiConverter.class.isAssignableFrom(converterClass)) {
502            options.add(NO_CONSOLE_NO_ANSI + '=' + noConsoleNoAnsi);
503        }
504        // Work around the regression bug in Class.getDeclaredMethods() in Oracle Java in version > 1.6.0_17:
505        // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6815786
506        final Method[] methods = converterClass.getDeclaredMethods();
507        Method newInstanceMethod = null;
508        for (final Method method : methods) {
509            if (Modifier.isStatic(method.getModifiers()) && method.getDeclaringClass().equals(converterClass)
510                    && method.getName().equals("newInstance")) {
511                if (newInstanceMethod == null) {
512                    newInstanceMethod = method;
513                } else if (method.getReturnType().equals(newInstanceMethod.getReturnType())) {
514                    LOGGER.error("Class " + converterClass + " cannot contain multiple static newInstance methods");
515                    return null;
516                }
517            }
518        }
519        if (newInstanceMethod == null) {
520            LOGGER.error("Class " + converterClass + " does not contain a static newInstance method");
521            return null;
522        }
523
524        final Class<?>[] parmTypes = newInstanceMethod.getParameterTypes();
525        final Object[] parms = parmTypes.length > 0 ? new Object[parmTypes.length] : null;
526
527        if (parms != null) {
528            int i = 0;
529            boolean errors = false;
530            for (final Class<?> clazz : parmTypes) {
531                if (clazz.isArray() && clazz.getName().equals("[Ljava.lang.String;")) {
532                    final String[] optionsArray = options.toArray(new String[options.size()]);
533                    parms[i] = optionsArray;
534                } else if (clazz.isAssignableFrom(Configuration.class)) {
535                    parms[i] = config;
536                } else {
537                    LOGGER.error("Unknown parameter type " + clazz.getName() + " for static newInstance method of "
538                            + converterClass.getName());
539                    errors = true;
540                }
541                ++i;
542            }
543            if (errors) {
544                return null;
545            }
546        }
547
548        try {
549            final Object newObj = newInstanceMethod.invoke(null, parms);
550
551            if (newObj instanceof PatternConverter) {
552                currentLiteral.delete(0, currentLiteral.length() - (converterId.length() - converterName.length()));
553
554                return (PatternConverter) newObj;
555            }
556            LOGGER.warn("Class {} does not extend PatternConverter.", converterClass.getName());
557        } catch (final Exception ex) {
558            LOGGER.error("Error creating converter for " + converterId, ex);
559        }
560
561        return null;
562    }
563
564    /**
565     * Processes a format specifier sequence.
566     *
567     * @param c
568     *            initial character of format specifier.
569     * @param pattern
570     *            conversion pattern
571     * @param start
572     *            current position in conversion pattern.
573     * @param currentLiteral
574     *            current literal.
575     * @param formattingInfo
576     *            current field specifier.
577     * @param rules
578     *            map of stock pattern converters keyed by format specifier.
579     * @param patternConverters
580     *            list to receive parsed pattern converter.
581     * @param formattingInfos
582     *            list to receive corresponding field specifier.
583     * @param noConsoleNoAnsi
584     *            TODO
585     * @param convertBackslashes if {@code true}, backslash characters are treated as escape characters and character
586     *            sequences like "\" followed by "t" (backslash+t) are converted to special characters like '\t' (tab).
587     * @return position after format specifier sequence.
588     */
589    private int finalizeConverter(final char c, final String pattern, final int start,
590            final StringBuilder currentLiteral, final FormattingInfo formattingInfo,
591            final Map<String, Class<PatternConverter>> rules, final List<PatternConverter> patternConverters,
592            final List<FormattingInfo> formattingInfos, final boolean noConsoleNoAnsi, final boolean convertBackslashes) {
593        int i = start;
594        final StringBuilder convBuf = new StringBuilder();
595        i = extractConverter(c, pattern, i, convBuf, currentLiteral);
596
597        final String converterId = convBuf.toString();
598
599        final List<String> options = new ArrayList<>();
600        i = extractOptions(pattern, i, options);
601
602        final PatternConverter pc = createConverter(converterId, currentLiteral, rules, options, noConsoleNoAnsi);
603
604        if (pc == null) {
605            StringBuilder msg;
606
607            if (Strings.isEmpty(converterId)) {
608                msg = new StringBuilder("Empty conversion specifier starting at position ");
609            } else {
610                msg = new StringBuilder("Unrecognized conversion specifier [");
611                msg.append(converterId);
612                msg.append("] starting at position ");
613            }
614
615            msg.append(Integer.toString(i));
616            msg.append(" in conversion pattern.");
617
618            LOGGER.error(msg.toString());
619
620            patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString(), convertBackslashes));
621            formattingInfos.add(FormattingInfo.getDefault());
622        } else {
623            patternConverters.add(pc);
624            formattingInfos.add(formattingInfo);
625
626            if (currentLiteral.length() > 0) {
627                patternConverters
628                        .add(new LiteralPatternConverter(config, currentLiteral.toString(), convertBackslashes));
629                formattingInfos.add(FormattingInfo.getDefault());
630            }
631        }
632
633        currentLiteral.setLength(0);
634
635        return i;
636    }
637}