001 /*
002 * JBoss DNA (http://www.jboss.org/dna)
003 * See the COPYRIGHT.txt file distributed with this work for information
004 * regarding copyright ownership. Some portions may be licensed
005 * to Red Hat, Inc. under one or more contributor license agreements.
006 * See the AUTHORS.txt file in the distribution for a full listing of
007 * individual contributors.
008 *
009 * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010 * is licensed to you under the terms of the GNU Lesser General Public License as
011 * published by the Free Software Foundation; either version 2.1 of
012 * the License, or (at your option) any later version.
013 *
014 * JBoss DNA is distributed in the hope that it will be useful,
015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017 * Lesser General Public License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this software; if not, write to the Free
021 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023 */
024 package org.jboss.dna.graph.mimetype;
025
026 import java.io.IOException;
027 import java.io.InputStream;
028 import java.util.Collections;
029 import java.util.HashMap;
030 import java.util.HashSet;
031 import java.util.List;
032 import java.util.Map;
033 import java.util.Set;
034 import java.util.regex.Matcher;
035 import java.util.regex.Pattern;
036 import net.jcip.annotations.Immutable;
037 import org.jboss.dna.common.i18n.I18n;
038 import org.jboss.dna.common.util.CheckArg;
039 import org.jboss.dna.common.util.IoUtil;
040 import org.jboss.dna.common.util.Logger;
041 import org.jboss.dna.common.util.StringUtil;
042 import org.jboss.dna.graph.GraphI18n;
043
044 /**
045 * A {@link MimeTypeDetector} that attempts to match the extension of the supplied name against a set of known file extensions.
046 *
047 * @author Randall Hauch
048 */
049 @Immutable
050 public class ExtensionBasedMimeTypeDetector implements MimeTypeDetector {
051
052 /**
053 * The default location of the properties file containing the extension patterns to MIME types. Value is "{@value} ".
054 */
055 public static final String MIME_TYPE_EXTENSIONS_RESOURCE_PATH = "/org/jboss/dna/graph/mime.types";
056 // public static final String MIME_TYPE_EXTENSIONS_RESOURCE_PATH = "/org/jboss/dna/graph/MimeTypes.properties";
057
058 /**
059 * The mapping of extension (which includes the leading '.') to MIME type.
060 */
061 private final Map<String, String> mimeTypesByExtension;
062
063 /**
064 * Create a default instance of the extension-based MIME type detector. The set of extension patterns to MIME-types is loaded
065 * from the "org/jboss/dna/graph/mime.types" classpath resource.
066 */
067 public ExtensionBasedMimeTypeDetector() {
068 this(null, true);
069 }
070
071 /**
072 * Create an instance of the extension-based MIME type detector by using the supplied mappings. The set of extension patterns
073 * to MIME-types is loaded from the "org/jboss/dna/graph/mime.types" classpath resource, but the supplied extension mappings
074 * override any default mappings.
075 *
076 * @param extensionsToMimeTypes the mapping of extension patterns to MIME types, which will override the default mappings; may
077 * be null if the default mappings are to be used
078 */
079 public ExtensionBasedMimeTypeDetector( Map<String, String> extensionsToMimeTypes ) {
080 this(extensionsToMimeTypes, true);
081 }
082
083 /**
084 * Create an instance of the extension-based MIME type detector by using the supplied mappings. If requested, the set of
085 * extension patterns to MIME-types is loaded from the "org/jboss/dna/graph/mime.types" classpath resource and any supplied
086 * extension mappings override any default mappings.
087 *
088 * @param extensionsToMimeTypes the mapping of extension patterns to MIME types, which will override the default mappings; may
089 * be null if the default mappings are to be used
090 * @param initWithDefaults true if the default mappings are to be loaded first
091 */
092 public ExtensionBasedMimeTypeDetector( Map<String, String> extensionsToMimeTypes,
093 boolean initWithDefaults ) {
094 Map<String, String> mappings = getDefaultMappings();
095 if (extensionsToMimeTypes != null) {
096 for (Map.Entry<String, String> entry : extensionsToMimeTypes.entrySet()) {
097 String extensionString = entry.getKey();
098 if (extensionString == null) continue;
099 // Lowercase, trime, and remove all leading '.' characters ...
100 extensionString = extensionString.toLowerCase().trim().replaceAll("^.+", "");
101 if (extensionString.length() == 0) continue;
102 String mimeType = entry.getValue();
103 if (mimeType == null) continue;
104 mimeType = entry.getValue().trim();
105 if (mimeType.length() == 0) continue;
106 assert extensionString.length() != 0;
107 assert mimeType.length() != 0;
108 mappings.put(extensionString, mimeType);
109 }
110 }
111 // Now put the mappings into the different maps ...
112 Map<String, String> mappingsByAnyCharExtension = new HashMap<String, String>();
113 for (Map.Entry<String, String> entry : mappings.entrySet()) {
114 String extensionString = entry.getKey();
115 String mimeType = entry.getValue();
116 assert extensionString != null;
117 assert extensionString.length() != 0;
118 assert mimeType != null;
119 assert mimeType.length() != 0;
120 mappingsByAnyCharExtension.put("." + extensionString, mimeType);
121 }
122 mimeTypesByExtension = Collections.unmodifiableMap(mappingsByAnyCharExtension);
123 }
124
125 /**
126 * Load the default extensions from {@link #MIME_TYPE_EXTENSIONS_RESOURCE_PATH}, which can either be a property file or a
127 * tab-delimited *nix-style MIME types file (common in web servers and libraries). If an extension applies to more than one
128 * MIME type, the first one in the file wins.
129 *
130 * @return the default mappings; never null
131 */
132 protected static Map<String, String> getDefaultMappings() {
133 Map<String, Set<String>> duplicates = new HashMap<String, Set<String>>();
134 return load(ExtensionBasedMimeTypeDetector.class.getResourceAsStream(MIME_TYPE_EXTENSIONS_RESOURCE_PATH), duplicates);
135 }
136
137 /**
138 * Load the default extensions from the supplied stream, which may provide the contents in the format of property file or a
139 * tab-delimited *nix-style MIME types file (common in web servers and libraries). If an extension applies to more than one
140 * MIME type, the first one in the file wins.
141 *
142 * @param stream the stream containing the content; may not be null
143 * @param duplicateMimeTypesByExtension a map into which any extension should be placed if there are multiple MIME types that
144 * apply; may be null if this information is not required
145 * @return the default mappings; never null
146 */
147 protected static Map<String, String> load( InputStream stream,
148 Map<String, Set<String>> duplicateMimeTypesByExtension ) {
149 CheckArg.isNotNull(stream, "stream");
150 // Create a Regex pattern that can be used for each line. This pattern looks for a mime type
151 // (which may contain no whitespace or '=') followed by an optional whitespace, an optional equals sign,
152 // optionally more whitespace, and finally by a string of one or more extensions.
153 Pattern linePattern = Pattern.compile("\\s*([^\\s=]+)\\s*=?\\s*(.*)");
154 List<String> lines = null;
155 try {
156 String content = IoUtil.read(stream);
157 lines = StringUtil.splitLines(content);
158 } catch (IOException e) {
159 I18n msg = GraphI18n.unableToAccessResourceFileFromClassLoader;
160 Logger.getLogger(ExtensionBasedMimeTypeDetector.class).warn(e, msg, MIME_TYPE_EXTENSIONS_RESOURCE_PATH);
161 }
162 Map<String, String> mimeTypesByExtension = new HashMap<String, String>();
163 if (lines != null) {
164 for (String line : lines) {
165 line = line.trim();
166 if (line.length() == 0 || line.startsWith("#")) continue;
167 // Apply the pattern to each line ...
168 Matcher matcher = linePattern.matcher(line);
169 if (matcher.matches()) {
170 String mimeType = matcher.group(1).trim().toLowerCase();
171 String extensions = matcher.group(2).trim().toLowerCase();
172 if (extensions.length() != 0) {
173 // A valid mime type with at least one extension was found, so for each extension ...
174 for (String extensionString : extensions.split("\\s+")) {
175 extensionString = extensionString.trim();
176 if (extensionString.length() != 0) {
177 // Register the extension with the MIME type ...
178 String existingMimeType = mimeTypesByExtension.put(extensionString, mimeType);
179 if (existingMimeType != null) {
180 // A MIME type already had this extension, so use the first one ...
181 mimeTypesByExtension.put(extensionString, existingMimeType);
182 if (duplicateMimeTypesByExtension != null) {
183 // And record the duplicate ...
184 Set<String> dups = duplicateMimeTypesByExtension.get(extensionString);
185 if (dups == null) {
186 dups = new HashSet<String>();
187 duplicateMimeTypesByExtension.put(extensionString, dups);
188 }
189 dups.add(existingMimeType);
190 dups.add(mimeType);
191 }
192 }
193 }
194 }
195 }
196 }
197 }
198 }
199 return mimeTypesByExtension;
200 }
201
202 /**
203 * {@inheritDoc}
204 *
205 * @see org.jboss.dna.graph.mimetype.MimeTypeDetector#mimeTypeOf(java.lang.String, java.io.InputStream)
206 */
207 public String mimeTypeOf( String name,
208 InputStream content ) {
209 if (name == null || name.length() == 0) return null;
210 String trimmedName = name.trim();
211 if (trimmedName.length() == 0) return null;
212
213 // Find the extension ...
214 int indexOfDelimiter = trimmedName.lastIndexOf('.');
215 if (indexOfDelimiter < 1) return null;
216 String extension = trimmedName.substring(indexOfDelimiter).toLowerCase();
217
218 // Look for a match ...
219 return mimeTypesByExtension.get(extension);
220 }
221 }