Source code

001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle;
021
022import java.io.IOException;
023import java.util.ArrayDeque;
024import java.util.ArrayList;
025import java.util.Arrays;
026import java.util.Collection;
027import java.util.Deque;
028import java.util.Iterator;
029import java.util.List;
030import java.util.Locale;
031import java.util.Map;
032import java.util.Optional;
033
034import javax.xml.parsers.ParserConfigurationException;
035
036import org.xml.sax.Attributes;
037import org.xml.sax.InputSource;
038import org.xml.sax.SAXException;
039import org.xml.sax.SAXParseException;
040
041import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
042import com.puppycrawl.tools.checkstyle.api.Configuration;
043import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
044import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
045
046/**
047 * Loads a configuration from a standard configuration XML file.
048 *
049 */
050@SuppressWarnings("UnrecognisedJavadocTag")
051public final class ConfigurationLoader {
052
053    /**
054     * Enum to specify behaviour regarding ignored modules.
055     */
056    public enum IgnoredModulesOptions {
057
058        /**
059         * Omit ignored modules.
060         */
061        OMIT,
062
063        /**
064         * Execute ignored modules.
065         */
066        EXECUTE,
067
068    }
069
070    /** The new public ID for version 1_3 of the configuration dtd. */
071    public static final String DTD_PUBLIC_CS_ID_1_3 =
072        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN";
073
074    /** The resource for version 1_3 of the configuration dtd. */
075    public static final String DTD_CONFIGURATION_NAME_1_3 =
076        "com/puppycrawl/tools/checkstyle/configuration_1_3.dtd";
077
078    /** Format of message for sax parse exception. */
079    private static final String SAX_PARSE_EXCEPTION_FORMAT = "%s - %s:%s:%s";
080
081    /** The public ID for version 1_0 of the configuration dtd. */
082    private static final String DTD_PUBLIC_ID_1_0 =
083        "-//Puppy Crawl//DTD Check Configuration 1.0//EN";
084
085    /** The new public ID for version 1_0 of the configuration dtd. */
086    private static final String DTD_PUBLIC_CS_ID_1_0 =
087        "-//Checkstyle//DTD Checkstyle Configuration 1.0//EN";
088
089    /** The resource for version 1_0 of the configuration dtd. */
090    private static final String DTD_CONFIGURATION_NAME_1_0 =
091        "com/puppycrawl/tools/checkstyle/configuration_1_0.dtd";
092
093    /** The public ID for version 1_1 of the configuration dtd. */
094    private static final String DTD_PUBLIC_ID_1_1 =
095        "-//Puppy Crawl//DTD Check Configuration 1.1//EN";
096
097    /** The new public ID for version 1_1 of the configuration dtd. */
098    private static final String DTD_PUBLIC_CS_ID_1_1 =
099        "-//Checkstyle//DTD Checkstyle Configuration 1.1//EN";
100
101    /** The resource for version 1_1 of the configuration dtd. */
102    private static final String DTD_CONFIGURATION_NAME_1_1 =
103        "com/puppycrawl/tools/checkstyle/configuration_1_1.dtd";
104
105    /** The public ID for version 1_2 of the configuration dtd. */
106    private static final String DTD_PUBLIC_ID_1_2 =
107        "-//Puppy Crawl//DTD Check Configuration 1.2//EN";
108
109    /** The new public ID for version 1_2 of the configuration dtd. */
110    private static final String DTD_PUBLIC_CS_ID_1_2 =
111        "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN";
112
113    /** The resource for version 1_2 of the configuration dtd. */
114    private static final String DTD_CONFIGURATION_NAME_1_2 =
115        "com/puppycrawl/tools/checkstyle/configuration_1_2.dtd";
116
117    /** The public ID for version 1_3 of the configuration dtd. */
118    private static final String DTD_PUBLIC_ID_1_3 =
119        "-//Puppy Crawl//DTD Check Configuration 1.3//EN";
120
121    /** Prefix for the exception when unable to parse resource. */
122    private static final String UNABLE_TO_PARSE_EXCEPTION_PREFIX = "unable to parse"
123            + " configuration stream";
124
125    /** Dollar sign literal. */
126    private static final char DOLLAR_SIGN = '$';
127    /** Dollar sign string. */
128    private static final String DOLLAR_SIGN_STRING = String.valueOf(DOLLAR_SIGN);
129
130    /** Static map of DTD IDs to resource names. */
131    private static final Map<String, String> ID_TO_RESOURCE_NAME_MAP = Map.ofEntries(
132        Map.entry(DTD_PUBLIC_ID_1_0, DTD_CONFIGURATION_NAME_1_0),
133        Map.entry(DTD_PUBLIC_ID_1_1, DTD_CONFIGURATION_NAME_1_1),
134        Map.entry(DTD_PUBLIC_ID_1_2, DTD_CONFIGURATION_NAME_1_2),
135        Map.entry(DTD_PUBLIC_ID_1_3, DTD_CONFIGURATION_NAME_1_3),
136        Map.entry(DTD_PUBLIC_CS_ID_1_0, DTD_CONFIGURATION_NAME_1_0),
137        Map.entry(DTD_PUBLIC_CS_ID_1_1, DTD_CONFIGURATION_NAME_1_1),
138        Map.entry(DTD_PUBLIC_CS_ID_1_2, DTD_CONFIGURATION_NAME_1_2),
139        Map.entry(DTD_PUBLIC_CS_ID_1_3, DTD_CONFIGURATION_NAME_1_3)
140    );
141
142    /** The SAX document handler. */
143    private final InternalLoader saxHandler;
144
145    /** Property resolver. */
146    private final PropertyResolver overridePropsResolver;
147
148    /** Flags if modules with the severity 'ignore' should be omitted. */
149    private final boolean omitIgnoredModules;
150
151    /** The thread mode configuration. */
152    private final ThreadModeSettings threadModeSettings;
153
154    /**
155     * Creates a new {@code ConfigurationLoader} instance.
156     *
157     * @param overrideProps resolver for overriding properties
158     * @param omitIgnoredModules {@code true} if ignored modules should be omitted
159     * @param threadModeSettings the thread mode configuration
160     * @throws ParserConfigurationException if an error occurs
161     * @throws SAXException if an error occurs
162     */
163    private ConfigurationLoader(final PropertyResolver overrideProps,
164                                final boolean omitIgnoredModules,
165                                final ThreadModeSettings threadModeSettings)
166            throws ParserConfigurationException, SAXException {
167        saxHandler = new InternalLoader();
168        overridePropsResolver = overrideProps;
169        this.omitIgnoredModules = omitIgnoredModules;
170        this.threadModeSettings = threadModeSettings;
171    }
172
173    /**
174     * Parses the specified input source loading the configuration information.
175     * The stream wrapped inside the source, if any, is NOT
176     * explicitly closed after parsing, it is the responsibility of the caller to close the stream.
177     *
178     * @param source the source that contains the configuration data
179     * @return the check configurations
180     * @throws IOException if an error occurs
181     * @throws SAXException if an error occurs
182     */
183    private Configuration parseInputSource(InputSource source)
184            throws IOException, SAXException {
185        saxHandler.parseInputSource(source);
186        return saxHandler.configuration;
187    }
188
189    /**
190     * Returns the module configurations in a specified file.
191     *
192     * @param config location of config file, can be either a URL or a filename
193     * @param overridePropsResolver overriding properties
194     * @return the check configurations
195     * @throws CheckstyleException if an error occurs
196     */
197    public static Configuration loadConfiguration(String config,
198            PropertyResolver overridePropsResolver)
199                    throws CheckstyleException {
200        return loadConfiguration(config, overridePropsResolver, IgnoredModulesOptions.EXECUTE);
201    }
202
203    /**
204     * Returns the module configurations in a specified file.
205     *
206     * @param config location of config file, can be either a URL or a filename
207     * @param overridePropsResolver overriding properties
208     * @param threadModeSettings the thread mode configuration
209     * @return the check configurations
210     * @throws CheckstyleException if an error occurs
211     */
212    public static Configuration loadConfiguration(String config,
213            PropertyResolver overridePropsResolver, ThreadModeSettings threadModeSettings)
214                    throws CheckstyleException {
215        return loadConfiguration(config, overridePropsResolver,
216                IgnoredModulesOptions.EXECUTE, threadModeSettings);
217    }
218
219    /**
220     * Returns the module configurations in a specified file.
221     *
222     * @param config location of config file, can be either a URL or a filename
223     * @param overridePropsResolver overriding properties
224     * @param ignoredModulesOptions {@code OMIT} if modules with severity
225     *            'ignore' should be omitted, {@code EXECUTE} otherwise
226     * @return the check configurations
227     * @throws CheckstyleException if an error occurs
228     */
229    public static Configuration loadConfiguration(String config,
230                                                  PropertyResolver overridePropsResolver,
231                                                  IgnoredModulesOptions ignoredModulesOptions)
232            throws CheckstyleException {
233        return loadConfiguration(config, overridePropsResolver, ignoredModulesOptions,
234                ThreadModeSettings.SINGLE_THREAD_MODE_INSTANCE);
235    }
236
237    /**
238     * Returns the module configurations from a specified input source.
239     * Note that if the source does wrap an open byte or character
240     * stream, clients are required to close that stream by themselves
241     *
242     * @param configSource the input stream to the Checkstyle configuration
243     * @param overridePropsResolver overriding properties
244     * @param ignoredModulesOptions {@code OMIT} if modules with severity
245     *            'ignore' should be omitted, {@code EXECUTE} otherwise
246     * @return the check configurations
247     * @throws CheckstyleException if an error occurs
248     */
249    public static Configuration loadConfiguration(InputSource configSource,
250                                                  PropertyResolver overridePropsResolver,
251                                                  IgnoredModulesOptions ignoredModulesOptions)
252            throws CheckstyleException {
253        return loadConfiguration(configSource, overridePropsResolver,
254                ignoredModulesOptions, ThreadModeSettings.SINGLE_THREAD_MODE_INSTANCE);
255    }
256
257    /**
258     * Returns the module configurations in a specified file.
259     *
260     * @param config location of config file, can be either a URL or a filename
261     * @param overridePropsResolver overriding properties
262     * @param ignoredModulesOptions {@code OMIT} if modules with severity
263     *            'ignore' should be omitted, {@code EXECUTE} otherwise
264     * @param threadModeSettings the thread mode configuration
265     * @return the check configurations
266     * @throws CheckstyleException if an error occurs
267     */
268    public static Configuration loadConfiguration(String config,
269                                                  PropertyResolver overridePropsResolver,
270                                                  IgnoredModulesOptions ignoredModulesOptions,
271                                                  ThreadModeSettings threadModeSettings)
272            throws CheckstyleException {
273        return loadConfiguration(CommonUtil.sourceFromFilename(config), overridePropsResolver,
274                ignoredModulesOptions, threadModeSettings);
275    }
276
277    /**
278     * Returns the module configurations from a specified input source.
279     * Note that if the source does wrap an open byte or character
280     * stream, clients are required to close that stream by themselves
281     *
282     * @param configSource the input stream to the Checkstyle configuration
283     * @param overridePropsResolver overriding properties
284     * @param ignoredModulesOptions {@code OMIT} if modules with severity
285     *            'ignore' should be omitted, {@code EXECUTE} otherwise
286     * @param threadModeSettings the thread mode configuration
287     * @return the check configurations
288     * @throws CheckstyleException if an error occurs
289     * @noinspection WeakerAccess
290     * @noinspectionreason WeakerAccess - we avoid 'protected' when possible
291     */
292    public static Configuration loadConfiguration(InputSource configSource,
293                                                  PropertyResolver overridePropsResolver,
294                                                  IgnoredModulesOptions ignoredModulesOptions,
295                                                  ThreadModeSettings threadModeSettings)
296            throws CheckstyleException {
297        try {
298            final boolean omitIgnoreModules = ignoredModulesOptions == IgnoredModulesOptions.OMIT;
299            final ConfigurationLoader loader =
300                    new ConfigurationLoader(overridePropsResolver,
301                            omitIgnoreModules, threadModeSettings);
302            return loader.parseInputSource(configSource);
303        }
304        catch (final SAXParseException exc) {
305            final String message = String.format(Locale.ROOT, SAX_PARSE_EXCEPTION_FORMAT,
306                    UNABLE_TO_PARSE_EXCEPTION_PREFIX,
307                    exc.getMessage(), exc.getLineNumber(), exc.getColumnNumber());
308            throw new CheckstyleException(message, exc);
309        }
310        catch (final ParserConfigurationException | IOException | SAXException exc) {
311            throw new CheckstyleException(UNABLE_TO_PARSE_EXCEPTION_PREFIX, exc);
312        }
313    }
314
315    /**
316     * Implements the SAX document handler interfaces, so they do not
317     * appear in the public API of the ConfigurationLoader.
318     */
319    private final class InternalLoader extends XmlLoader {
320
321        /** Module elements. */
322        private static final String MODULE = "module";
323        /** Name attribute. */
324        private static final String NAME = "name";
325        /** Property element. */
326        private static final String PROPERTY = "property";
327        /** Value attribute. */
328        private static final String VALUE = "value";
329        /** Default attribute. */
330        private static final String DEFAULT = "default";
331        /** Name of the severity property. */
332        private static final String SEVERITY = "severity";
333        /** Name of the message element. */
334        private static final String MESSAGE = "message";
335        /** Name of the message element. */
336        private static final String METADATA = "metadata";
337        /** Name of the key attribute. */
338        private static final String KEY = "key";
339
340        /** The loaded configurations. */
341        private final Deque<DefaultConfiguration> configStack = new ArrayDeque<>();
342
343        /** The Configuration that is being built. */
344        private Configuration configuration;
345
346        /**
347         * Creates a new InternalLoader.
348         *
349         * @throws ParserConfigurationException if an error occurs
350         * @throws SAXException if an error occurs
351         */
352        private InternalLoader()
353                throws SAXException, ParserConfigurationException {
354            super(ID_TO_RESOURCE_NAME_MAP);
355        }
356
357        /**
358         * Replaces {@code ${xxx}} style constructions in the given value
359         * with the string value of the corresponding data types.
360         *
361         * <p>Code copied from
362         * <a href="https://github.com/apache/ant/blob/master/src/main/org/apache/tools/ant/ProjectHelper.java">
363         * ant
364         * </a>
365         *
366         * @param value The string to be scanned for property references. Must not be {@code null}.
367         * @param defaultValue default to use if one of the properties in value
368         *              cannot be resolved from props.
369         *
370         * @return the original string with the properties replaced.
371         * @throws CheckstyleException if the string contains an opening
372         *                           {@code ${} without a closing
373         *                           {@code }}
374         */
375        private String replaceProperties(
376                String value, String defaultValue)
377                        throws CheckstyleException {
378
379            final List<String> fragments = new ArrayList<>();
380            final List<String> propertyRefs = new ArrayList<>();
381            parsePropertyString(value, fragments, propertyRefs);
382
383            final StringBuilder sb = new StringBuilder(256);
384            final Iterator<String> fragmentsIterator = fragments.iterator();
385            final Iterator<String> propertyRefsIterator = propertyRefs.iterator();
386            while (fragmentsIterator.hasNext()) {
387                String fragment = fragmentsIterator.next();
388                if (fragment == null) {
389                    final String propertyName = propertyRefsIterator.next();
390                    fragment = overridePropsResolver.resolve(propertyName);
391                    if (fragment == null) {
392                        if (defaultValue != null) {
393                            sb.replace(0, sb.length(), defaultValue);
394                            break;
395                        }
396                        throw new CheckstyleException(
397                            "Property ${" + propertyName + "} has not been set");
398                    }
399                }
400                sb.append(fragment);
401            }
402
403            return sb.toString();
404        }
405
406        /**
407         * Parses a string containing {@code ${xxx}} style property
408         * references into two collections. The first one is a collection
409         * of text fragments, while the other is a set of string property names.
410         * {@code null} entries in the first collection indicate a property
411         * reference from the second collection.
412         *
413         * <p>Code copied from
414         * <a href="https://github.com/apache/ant/blob/master/src/main/org/apache/tools/ant/ProjectHelper.java">
415         * ant
416         * </a>
417         *
418         * @param value     Text to parse. Must not be {@code null}.
419         * @param fragments Collection to add text fragments to.
420         *                  Must not be {@code null}.
421         * @param propertyRefs Collection to add property names to.
422         *                     Must not be {@code null}.
423         *
424         * @throws CheckstyleException if the string contains an opening
425         *                           {@code ${} without a closing
426         *                           {@code }}
427         */
428        private static void parsePropertyString(String value,
429                                               Collection<String> fragments,
430                                               Collection<String> propertyRefs)
431                throws CheckstyleException {
432            int prev = 0;
433            // search for the next instance of $ from the 'prev' position
434            int pos = value.indexOf(DOLLAR_SIGN, prev);
435            while (pos >= 0) {
436                // if there was any text before this, add it as a fragment
437                if (pos > 0) {
438                    fragments.add(value.substring(prev, pos));
439                }
440                // if we are at the end of the string, we tack on a $
441                // then move past it
442                if (pos == value.length() - 1) {
443                    fragments.add(DOLLAR_SIGN_STRING);
444                    prev = pos + 1;
445                }
446                else if (value.charAt(pos + 1) == '{') {
447                    // property found, extract its name or bail on a typo
448                    final int endName = value.indexOf('}', pos);
449                    if (endName == -1) {
450                        throw new CheckstyleException("Syntax error in property: "
451                                                        + value);
452                    }
453                    final String propertyName = value.substring(pos + 2, endName);
454                    fragments.add(null);
455                    propertyRefs.add(propertyName);
456                    prev = endName + 1;
457                }
458                else {
459                    if (value.charAt(pos + 1) == DOLLAR_SIGN) {
460                        // backwards compatibility two $ map to one mode
461                        fragments.add(DOLLAR_SIGN_STRING);
462                    }
463                    else {
464                        // new behaviour: $X maps to $X for all values of X!='$'
465                        fragments.add(value.substring(pos, pos + 2));
466                    }
467                    prev = pos + 2;
468                }
469
470                // search for the next instance of $ from the 'prev' position
471                pos = value.indexOf(DOLLAR_SIGN, prev);
472            }
473            // no more $ signs found
474            // if there is any tail to the file, append it
475            if (prev < value.length()) {
476                fragments.add(value.substring(prev));
477            }
478        }
479
480        @Override
481        public void startElement(String uri,
482                                 String localName,
483                                 String qName,
484                                 Attributes attributes)
485                throws SAXException {
486            if (MODULE.equals(qName)) {
487                // create configuration
488                final String originalName = attributes.getValue(NAME);
489                final String name = threadModeSettings.resolveName(originalName);
490                final DefaultConfiguration conf =
491                    new DefaultConfiguration(name, threadModeSettings);
492
493                if (configStack.isEmpty()) {
494                    // save top config
495                    configuration = conf;
496                }
497                else {
498                    // add configuration to it's parent
499                    final DefaultConfiguration top =
500                        configStack.peek();
501                    top.addChild(conf);
502                }
503
504                configStack.push(conf);
505            }
506            else if (PROPERTY.equals(qName)) {
507                // extract value and name
508                final String attributesValue = attributes.getValue(VALUE);
509
510                final String value;
511                try {
512                    value = replaceProperties(attributesValue, attributes.getValue(DEFAULT));
513                }
514                catch (final CheckstyleException exc) {
515                    // -@cs[IllegalInstantiation] SAXException is in the overridden
516                    // method signature
517                    throw new SAXException(attributesValue, exc);
518                }
519
520                final String name = attributes.getValue(NAME);
521
522                // add to attributes of configuration
523                final DefaultConfiguration top =
524                    configStack.peek();
525                top.addProperty(name, value);
526            }
527            else if (MESSAGE.equals(qName)) {
528                // extract key and value
529                final String key = attributes.getValue(KEY);
530                final String value = attributes.getValue(VALUE);
531
532                // add to messages of configuration
533                final DefaultConfiguration top = configStack.peek();
534                top.addMessage(key, value);
535            }
536            else {
537                if (!METADATA.equals(qName)) {
538                    throw new IllegalStateException("Unknown name:" + qName + ".");
539                }
540            }
541        }
542
543        @Override
544        public void endElement(String uri,
545                               String localName,
546                               String qName)
547                throws SAXException {
548            if (MODULE.equals(qName)) {
549                final Configuration recentModule =
550                    configStack.pop();
551
552                // get severity attribute if it exists
553                Optional<SeverityLevel> level = Optional.empty();
554                if (containsAttribute(recentModule, SEVERITY)) {
555                    try {
556                        final String severity = recentModule.getProperty(SEVERITY);
557                        level = Optional.of(SeverityLevel.getInstance(severity));
558                    }
559                    catch (final CheckstyleException exc) {
560                        // -@cs[IllegalInstantiation] SAXException is in the overridden
561                        // method signature
562                        throw new SAXException(
563                                "Problem during accessing '" + SEVERITY + "' attribute for "
564                                        + recentModule.getName(), exc);
565                    }
566                }
567
568                // omit this module if these should be omitted and the module
569                // has the severity 'ignore'
570                final boolean omitModule = omitIgnoredModules
571                    && level.isPresent() && level.get() == SeverityLevel.IGNORE;
572
573                if (omitModule && !configStack.isEmpty()) {
574                    final DefaultConfiguration parentModule = configStack.peek();
575                    parentModule.removeChild(recentModule);
576                }
577            }
578        }
579
580        /**
581         * Util method to recheck attribute in module.
582         *
583         * @param module module to check
584         * @param attributeName name of attribute in module to find
585         * @return true if attribute is present in module
586         */
587        private static boolean containsAttribute(Configuration module, String attributeName) {
588            final String[] names = module.getPropertyNames();
589            final Optional<String> result = Arrays.stream(names)
590                    .filter(name -> name.equals(attributeName)).findFirst();
591            return result.isPresent();
592        }
593
594    }
595
596}