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.commons.configuration.resolver;
018    
019    import org.xml.sax.EntityResolver;
020    import org.xml.sax.InputSource;
021    import org.xml.sax.SAXException;
022    import org.apache.xml.resolver.CatalogException;
023    import org.apache.xml.resolver.readers.CatalogReader;
024    import org.apache.commons.logging.Log;
025    import org.apache.commons.logging.LogFactory;
026    import org.apache.commons.configuration.FileSystem;
027    import org.apache.commons.configuration.ConfigurationException;
028    import org.apache.commons.configuration.ConfigurationUtils;
029    import org.apache.commons.lang.text.StrSubstitutor;
030    
031    import java.io.InputStream;
032    import java.io.IOException;
033    import java.net.FileNameMap;
034    import java.net.URLConnection;
035    import java.net.URL;
036    import java.util.Vector;
037    
038    /**
039     * Thin wrapper around xml commons CatalogResolver to allow list of catalogs
040     * to be provided.
041     * @author <a
042     * href="http://commons.apache.org/configuration/team-list.html">Commons
043     * Configuration team</a>
044     * @since 1.7
045     * @version $Id: CatalogResolver.java 952631 2010-06-08 12:09:29Z sebb $
046     */
047    public class CatalogResolver implements EntityResolver
048    {
049        /**
050         * Debug everything.
051         */
052        private static final int DEBUG_ALL = 9;
053    
054        /**
055         * Normal debug setting.
056         */
057        private static final int DEBUG_NORMAL = 4;
058    
059        /**
060         * Debug nothing.
061         */
062        private static final int DEBUG_NONE = 0;
063    
064        /**
065         * The CatalogManager
066         */
067        protected CatalogManager manager = new CatalogManager();
068    
069        /**
070         * The FileSystem in use.
071         */
072        protected FileSystem fs = FileSystem.getDefaultFileSystem();
073    
074        /**
075         * The CatalogResolver
076         */
077        private org.apache.xml.resolver.tools.CatalogResolver resolver;
078    
079        /**
080         * Stores the logger.
081         */
082        private Log log;
083    
084        /**
085         * Constructs the CatalogResolver
086         */
087        public CatalogResolver()
088        {
089            manager.setIgnoreMissingProperties(true);
090            manager.setUseStaticCatalog(false);
091            manager.setFileSystem(fs);
092            setLogger(null);
093        }
094    
095        /**
096         * Set the list of catalog file names
097         *
098         * @param catalogs The delimited list of catalog files.
099         */
100        public void setCatalogFiles(String catalogs)
101        {
102            manager.setCatalogFiles(catalogs);
103        }
104    
105        /**
106         * Set the FileSystem.
107         * @param fileSystem The FileSystem.
108         */
109        public void setFileSystem(FileSystem fileSystem)
110        {
111            this.fs = fileSystem;
112            manager.setFileSystem(fileSystem);
113        }
114    
115        /**
116         * Set the base path.
117         * @param baseDir The base path String.
118         */
119        public void setBaseDir(String baseDir)
120        {
121            manager.setBaseDir(baseDir);
122        }
123    
124        /**
125         * Set the StrSubstitutor.
126         * @param substitutor The StrSubstitutor.
127         */
128        public void setSubstitutor(StrSubstitutor substitutor)
129        {
130            manager.setSubstitutor(substitutor);
131        }
132    
133        /**
134         * Enables debug logging of xml-commons Catalog processing.
135         * @param debug True if debugging should be enabled, false otherwise.
136         */
137        public void setDebug(boolean debug)
138        {
139            if (debug)
140            {
141                manager.setVerbosity(DEBUG_ALL);
142            }
143            else
144            {
145                manager.setVerbosity(DEBUG_NONE);
146            }
147        }
148    
149        /**
150         * Implements the <code>resolveEntity</code> method
151         * for the SAX interface.
152         * <p/>
153         * <p>Presented with an optional public identifier and a system
154         * identifier, this function attempts to locate a mapping in the
155         * catalogs.</p>
156         * <p/>
157         * <p>If such a mapping is found, the resolver attempts to open
158         * the mapped value as an InputSource and return it. Exceptions are
159         * ignored and null is returned if the mapped value cannot be opened
160         * as an input source.</p>
161         * <p/>
162         * <p>If no mapping is found (or an error occurs attempting to open
163         * the mapped value as an input source), null is returned and the system
164         * will use the specified system identifier as if no entityResolver
165         * was specified.</p>
166         *
167         * @param publicId The public identifier for the entity in question.
168         *                 This may be null.
169         * @param systemId The system identifier for the entity in question.
170         *                 XML requires a system identifier on all external entities, so this
171         *                 value is always specified.
172         * @return An InputSource for the mapped identifier, or null.
173         * @throws SAXException if an error occurs.
174         */
175        public InputSource resolveEntity(String publicId, String systemId)
176                throws SAXException
177        {
178            String resolved = getResolver().getResolvedEntity(publicId, systemId);
179    
180            if (resolved != null)
181            {
182                String badFilePrefix = "file://";
183                String correctFilePrefix = "file:///";
184    
185                // Java 5 has a bug when constructing file URLS
186                if (resolved.startsWith(badFilePrefix) && !resolved.startsWith(correctFilePrefix))
187                {
188                    resolved = correctFilePrefix + resolved.substring(badFilePrefix.length());
189                }
190    
191                try
192                {
193                    InputStream is = fs.getInputStream(null, resolved);
194                    InputSource iSource = new InputSource(resolved);
195                    iSource.setPublicId(publicId);
196                    iSource.setByteStream(is);
197                    return iSource;
198                }
199                catch (Exception e)
200                {
201                    log.warn("Failed to create InputSource for " + resolved + " ("
202                                    + e.toString() + ")");
203                    return null;
204                }
205            }
206    
207            return null;
208        }
209    
210        /**
211         * Returns the logger used by this configuration object.
212         *
213         * @return the logger
214         */
215        public Log getLogger()
216        {
217            return log;
218        }
219    
220        /**
221         * Allows to set the logger to be used by this configuration object. This
222         * method makes it possible for clients to exactly control logging behavior.
223         * Per default a logger is set that will ignore all log messages. Derived
224         * classes that want to enable logging should call this method during their
225         * initialization with the logger to be used.
226         *
227         * @param log the new logger
228         */
229        public void setLogger(Log log)
230        {
231            this.log = (log != null) ? log : LogFactory.getLog(CatalogResolver.class);
232        }
233    
234        private synchronized org.apache.xml.resolver.tools.CatalogResolver getResolver()
235        {
236            if (resolver == null)
237            {
238                resolver = new org.apache.xml.resolver.tools.CatalogResolver(manager);
239            }
240            return resolver;
241        }
242    
243        /**
244         * Extend the CatalogManager to make the FileSystem and base directory accessible.
245         */
246        public static class CatalogManager extends org.apache.xml.resolver.CatalogManager
247        {
248            /** The static catalog used by this manager. */
249            private static org.apache.xml.resolver.Catalog staticCatalog;
250    
251            /** The FileSystem */
252            private FileSystem fs;
253    
254            /** The base directory */
255            private String baseDir = System.getProperty("user.dir");
256    
257            /** The String Substitutor */
258            private StrSubstitutor substitutor;
259    
260            /**
261             * Set the FileSystem
262             * @param fileSystem The FileSystem in use.
263             */
264            public void setFileSystem(FileSystem fileSystem)
265            {
266                this.fs = fileSystem;
267            }
268    
269            /**
270             * Retrieve the FileSystem.
271             * @return The FileSystem.
272             */
273            public FileSystem getFileSystem()
274            {
275                return this.fs;
276            }
277    
278            /**
279             * Set the base directory.
280             * @param baseDir The base directory.
281             */
282            public void setBaseDir(String baseDir)
283            {
284                if (baseDir != null)
285                {
286                    this.baseDir = baseDir;
287                }
288            }
289    
290            /**
291             * Return the base directory.
292             * @return The base directory.
293             */
294            public String getBaseDir()
295            {
296                return this.baseDir;
297            }
298    
299            public void setSubstitutor(StrSubstitutor substitutor)
300            {
301                this.substitutor = substitutor;
302            }
303    
304            public StrSubstitutor getStrSubstitutor()
305            {
306                return this.substitutor;
307            }
308    
309    
310            /**
311             * Get a new catalog instance. This method is only overridden because xml-resolver
312             * might be in a parent ClassLoader and will be incapable of loading our Catalog
313             * implementation.
314             *
315             * This method always returns a new instance of the underlying catalog class.
316             * @return the Catalog.
317             */
318            public org.apache.xml.resolver.Catalog getPrivateCatalog()
319            {
320                org.apache.xml.resolver.Catalog catalog = staticCatalog;
321    
322                if (catalog == null || !getUseStaticCatalog())
323                {
324                    try
325                    {
326                        catalog = new Catalog();
327                        catalog.setCatalogManager(this);
328                        catalog.setupReaders();
329                        catalog.loadSystemCatalogs();
330                    }
331                    catch (Exception ex)
332                    {
333                        ex.printStackTrace();
334                    }
335    
336                    if (getUseStaticCatalog())
337                    {
338                        staticCatalog = catalog;
339                    }
340                }
341    
342                return catalog;
343            }
344    
345            /**
346             * Get a catalog instance.
347             *
348             * If this manager uses static catalogs, the same static catalog will
349             * always be returned. Otherwise a new catalog will be returned.
350             * @return The Catalog.
351             */
352            public org.apache.xml.resolver.Catalog getCatalog()
353            {
354                return getPrivateCatalog();
355            }
356        }
357    
358        /**
359         * Overrides the Catalog implementation to use the underlying FileSystem.
360         */
361        public static class Catalog extends org.apache.xml.resolver.Catalog
362        {
363            /** The FileSystem */
364            private FileSystem fs;
365    
366            /** FileNameMap to determine the mime type */
367            private FileNameMap fileNameMap = URLConnection.getFileNameMap();
368    
369            /**
370             * Load the catalogs.
371             * @throws IOException if an error occurs.
372             */
373            public void loadSystemCatalogs() throws IOException
374            {
375                fs = ((CatalogManager) catalogManager).getFileSystem();
376                String base = ((CatalogManager) catalogManager).getBaseDir();
377    
378                Vector catalogs = catalogManager.getCatalogFiles();
379                if (catalogs != null)
380                {
381                    for (int count = 0; count < catalogs.size(); count++)
382                    {
383                        String fileName = (String) catalogs.elementAt(count);
384    
385                        URL url = null;
386                        InputStream is = null;
387    
388                        try
389                        {
390                            url = ConfigurationUtils.locate(fs, base, fileName);
391                            if (url != null)
392                            {
393                                is = fs.getInputStream(url);
394                            }
395                        }
396                        catch (ConfigurationException ce)
397                        {
398                            String name = (url == null) ? fileName : url.toString();
399                            // Ignore the exception.
400                            catalogManager.debug.message(DEBUG_ALL,
401                                "Unable to get input stream for " + name + ". " + ce.getMessage());
402                        }
403                        if (is != null)
404                        {
405                            String mimeType = fileNameMap.getContentTypeFor(fileName);
406                            try
407                            {
408                                if (mimeType != null)
409                                {
410                                    parseCatalog(mimeType, is);
411                                    continue;
412                                }
413                            }
414                            catch (Exception ex)
415                            {
416                                // Ignore the exception.
417                                catalogManager.debug.message(DEBUG_ALL,
418                                    "Exception caught parsing input stream for " + fileName + ". "
419                                    + ex.getMessage());
420                            }
421                            finally
422                            {
423                                is.close();
424                            }
425                        }
426                        parseCatalog(base, fileName);
427                    }
428                }
429    
430            }
431    
432            /**
433             * Parse the specified catalog file.
434             * @param baseDir The base directory, if not included in the file name.
435             * @param fileName The catalog file. May be a full URI String.
436             * @throws IOException If an error occurs.
437             */
438            public void parseCatalog(String baseDir, String fileName) throws IOException
439            {
440                base = ConfigurationUtils.locate(fs, baseDir, fileName);
441                catalogCwd = base;
442                default_override = catalogManager.getPreferPublic();
443                catalogManager.debug.message(DEBUG_NORMAL, "Parse catalog: " + fileName);
444    
445                boolean parsed = false;
446    
447                for (int count = 0; !parsed && count < readerArr.size(); count++)
448                {
449                    CatalogReader reader = (CatalogReader) readerArr.get(count);
450                    InputStream inStream;
451    
452                    try
453                    {
454                        inStream = fs.getInputStream(base);
455                    }
456                    catch (Exception ex)
457                    {
458                        catalogManager.debug.message(DEBUG_NORMAL, "Unable to access " + base
459                            + ex.getMessage());
460                        break;
461                    }
462    
463                    try
464                    {
465                        reader.readCatalog(this, inStream);
466                        parsed = true;
467                    }
468                    catch (CatalogException ce)
469                    {
470                        catalogManager.debug.message(DEBUG_NORMAL, "Parse failed for " + fileName
471                                + ce.getMessage());
472                        if (ce.getExceptionType() == CatalogException.PARSE_FAILED)
473                        {
474                            break;
475                        }
476                        else
477                        {
478                            // try again!
479                            continue;
480                        }
481                    }
482                    finally
483                    {
484                        try
485                        {
486                            inStream.close();
487                        }
488                        catch (IOException ioe)
489                        {
490                            // Ignore the exception.
491                            inStream = null;
492                        }
493                    }
494                }
495    
496                if (parsed)
497                {
498                    parsePendingCatalogs();
499                }
500            }
501    
502            /**
503             * Perform character normalization on a URI reference.
504             *
505             * @param uriref The URI reference
506             * @return The normalized URI reference.
507             */
508            protected String normalizeURI(String uriref)
509            {
510                StrSubstitutor substitutor = ((CatalogManager) catalogManager).getStrSubstitutor();
511                String resolved = substitutor != null ? substitutor.replace(uriref) : uriref;
512                return super.normalizeURI(resolved);
513            }
514        }
515    }