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.camel.impl;
018
019 import java.io.File;
020 import java.io.FileInputStream;
021 import java.io.IOException;
022 import java.io.InputStream;
023 import java.lang.annotation.Annotation;
024 import java.net.URL;
025 import java.net.URLConnection;
026 import java.net.URLDecoder;
027 import java.util.Arrays;
028 import java.util.Collections;
029 import java.util.Enumeration;
030 import java.util.HashSet;
031 import java.util.LinkedHashSet;
032 import java.util.Set;
033 import java.util.jar.JarEntry;
034 import java.util.jar.JarInputStream;
035
036 import org.apache.camel.impl.scan.AnnotatedWithAnyPackageScanFilter;
037 import org.apache.camel.impl.scan.AnnotatedWithPackageScanFilter;
038 import org.apache.camel.impl.scan.AssignableToPackageScanFilter;
039 import org.apache.camel.impl.scan.CompositePackageScanFilter;
040 import org.apache.camel.spi.PackageScanClassResolver;
041 import org.apache.camel.spi.PackageScanFilter;
042 import org.apache.camel.util.ObjectHelper;
043 import org.apache.commons.logging.Log;
044 import org.apache.commons.logging.LogFactory;
045
046 /**
047 * Default implement of {@link org.apache.camel.spi.PackageScanClassResolver}
048 */
049 public class DefaultPackageScanClassResolver implements PackageScanClassResolver {
050
051 protected final transient Log log = LogFactory.getLog(getClass());
052 private Set<ClassLoader> classLoaders;
053 private Set<PackageScanFilter> scanFilters;
054
055 public void addClassLoader(ClassLoader classLoader) {
056 getClassLoaders().add(classLoader);
057 }
058
059 public void addFilter(PackageScanFilter filter) {
060 if (scanFilters == null) {
061 scanFilters = new LinkedHashSet<PackageScanFilter>();
062 }
063 scanFilters.add(filter);
064 }
065
066 public Set<ClassLoader> getClassLoaders() {
067 if (classLoaders == null) {
068 classLoaders = new HashSet<ClassLoader>();
069 ClassLoader ccl = Thread.currentThread().getContextClassLoader();
070 if (ccl != null) {
071 if (log.isTraceEnabled()) {
072 log.trace("The thread context class loader: " + ccl + " is used to load the class");
073 }
074 classLoaders.add(ccl);
075 }
076 classLoaders.add(DefaultPackageScanClassResolver.class.getClassLoader());
077 }
078 return classLoaders;
079 }
080
081 public void setClassLoaders(Set<ClassLoader> classLoaders) {
082 this.classLoaders = classLoaders;
083 }
084
085 @SuppressWarnings("unchecked")
086 public Set<Class> findAnnotated(Class<? extends Annotation> annotation, String... packageNames) {
087 if (packageNames == null) {
088 return Collections.EMPTY_SET;
089 }
090
091 if (log.isDebugEnabled()) {
092 log.debug("Searching for annotations of " + annotation.getName() + " in packages: " + Arrays.asList(packageNames));
093 }
094
095 PackageScanFilter test = getCompositeFilter(new AnnotatedWithPackageScanFilter(annotation, true));
096 Set<Class> classes = new LinkedHashSet<Class>();
097 for (String pkg : packageNames) {
098 find(test, pkg, classes);
099 }
100
101 if (log.isDebugEnabled()) {
102 log.debug("Found: " + classes);
103 }
104
105 return classes;
106 }
107
108 @SuppressWarnings("unchecked")
109 public Set<Class> findAnnotated(Set<Class<? extends Annotation>> annotations, String... packageNames) {
110 if (packageNames == null) {
111 return Collections.EMPTY_SET;
112 }
113
114 if (log.isDebugEnabled()) {
115 log.debug("Searching for annotations of " + annotations + " in packages: " + Arrays.asList(packageNames));
116 }
117
118 PackageScanFilter test = getCompositeFilter(new AnnotatedWithAnyPackageScanFilter(annotations, true));
119 Set<Class> classes = new LinkedHashSet<Class>();
120 for (String pkg : packageNames) {
121 find(test, pkg, classes);
122 }
123
124 if (log.isDebugEnabled()) {
125 log.debug("Found: " + classes);
126 }
127
128 return classes;
129 }
130
131 @SuppressWarnings("unchecked")
132 public Set<Class> findImplementations(Class parent, String... packageNames) {
133 if (packageNames == null) {
134 return Collections.EMPTY_SET;
135 }
136
137 if (log.isDebugEnabled()) {
138 log.debug("Searching for implementations of " + parent.getName() + " in packages: " + Arrays.asList(packageNames));
139 }
140
141 PackageScanFilter test = getCompositeFilter(new AssignableToPackageScanFilter(parent));
142 Set<Class> classes = new LinkedHashSet<Class>();
143 for (String pkg : packageNames) {
144 find(test, pkg, classes);
145 }
146
147 if (log.isDebugEnabled()) {
148 log.debug("Found: " + classes);
149 }
150
151 return classes;
152 }
153
154 @SuppressWarnings("unchecked")
155 public Set<Class> findByFilter(PackageScanFilter filter, String... packageNames) {
156 if (packageNames == null) {
157 return Collections.EMPTY_SET;
158 }
159
160 Set<Class> classes = new LinkedHashSet<Class>();
161 for (String pkg : packageNames) {
162 find(filter, pkg, classes);
163 }
164
165 if (log.isDebugEnabled()) {
166 log.debug("Found: " + classes);
167 }
168
169 return classes;
170 }
171
172 protected void find(PackageScanFilter test, String packageName, Set<Class> classes) {
173 packageName = packageName.replace('.', '/');
174
175 Set<ClassLoader> set = getClassLoaders();
176
177 for (ClassLoader classLoader : set) {
178 find(test, packageName, classLoader, classes);
179 }
180 }
181
182 protected void find(PackageScanFilter test, String packageName, ClassLoader loader, Set<Class> classes) {
183 if (log.isTraceEnabled()) {
184 log.trace("Searching for: " + test + " in package: " + packageName + " using classloader: "
185 + loader.getClass().getName());
186 }
187
188 Enumeration<URL> urls;
189 try {
190 urls = getResources(loader, packageName);
191 if (!urls.hasMoreElements()) {
192 log.trace("No URLs returned by classloader");
193 }
194 } catch (IOException ioe) {
195 log.warn("Could not read package: " + packageName, ioe);
196 return;
197 }
198
199 while (urls.hasMoreElements()) {
200 URL url = null;
201 try {
202 url = urls.nextElement();
203 if (log.isTraceEnabled()) {
204 log.trace("URL from classloader: " + url);
205 }
206
207 String urlPath = url.getFile();
208 urlPath = URLDecoder.decode(urlPath, "UTF-8");
209 if (log.isTraceEnabled()) {
210 log.trace("Decoded urlPath: " + urlPath);
211 }
212
213 // If it's a file in a directory, trim the stupid file: spec
214 if (urlPath.startsWith("file:")) {
215 urlPath = urlPath.substring(5);
216 }
217
218 // osgi bundles should be skipped
219 if (url.toString().startsWith("bundle:") || urlPath.startsWith("bundle:")) {
220 log.trace("It's a virtual osgi bundle, skipping");
221 continue;
222 }
223
224 // Else it's in a JAR, grab the path to the jar
225 if (urlPath.indexOf('!') > 0) {
226 urlPath = urlPath.substring(0, urlPath.indexOf('!'));
227 }
228
229 if (log.isTraceEnabled()) {
230 log.trace("Scanning for classes in [" + urlPath + "] matching criteria: " + test);
231 }
232
233 File file = new File(urlPath);
234 if (file.isDirectory()) {
235 if (log.isDebugEnabled()) {
236 log.debug("Loading from directory: " + file);
237 }
238 loadImplementationsInDirectory(test, packageName, file, classes);
239 } else {
240 InputStream stream;
241 if (urlPath.startsWith("http:")) {
242 // load resources using http such as java webstart
243 log.debug("The current jar is accessed via http");
244 URL urlStream = new URL(urlPath);
245 URLConnection con = urlStream.openConnection();
246 // disable cache mainly to avoid jar file locking on Windows
247 con.setUseCaches(false);
248 stream = con.getInputStream();
249 } else {
250 stream = new FileInputStream(file);
251 }
252
253 if (log.isDebugEnabled()) {
254 log.debug("Loading from jar: " + file);
255 }
256 loadImplementationsInJar(test, packageName, stream, urlPath, classes);
257 }
258 } catch (IOException ioe) {
259 log.warn("Could not read entries in url: " + url, ioe);
260 }
261 }
262 }
263
264 /**
265 * Strategy to get the resources by the given classloader.
266 * <p/>
267 * Notice that in WebSphere platforms there is a {@link WebSpherePacakageScanClassResolver}
268 * to take care of WebSphere's odditiy of resource loading.
269 *
270 * @param loader the classloader
271 * @param packageName the packagename for the package to load
272 * @return URL's for the given package
273 * @throws IOException is thrown by the classloader
274 */
275 protected Enumeration<URL> getResources(ClassLoader loader, String packageName) throws IOException {
276 if (log.isTraceEnabled()) {
277 log.trace("Getting resource URL for package: " + packageName + " with classloader: " + loader);
278 }
279 return loader.getResources(packageName);
280 }
281
282 private PackageScanFilter getCompositeFilter(PackageScanFilter filter) {
283 if (scanFilters != null) {
284 CompositePackageScanFilter composite = new CompositePackageScanFilter(scanFilters);
285 composite.addFilter(filter);
286 return composite;
287 }
288 return filter;
289 }
290
291 /**
292 * Finds matches in a physical directory on a filesystem. Examines all files
293 * within a directory - if the File object is not a directory, and ends with
294 * <i>.class</i> the file is loaded and tested to see if it is acceptable
295 * according to the Test. Operates recursively to find classes within a
296 * folder structure matching the package structure.
297 *
298 * @param test a Test used to filter the classes that are discovered
299 * @param parent the package name up to this directory in the package
300 * hierarchy. E.g. if /classes is in the classpath and we wish to
301 * examine files in /classes/org/apache then the values of
302 * <i>parent</i> would be <i>org/apache</i>
303 * @param location a File object representing a directory
304 */
305 private void loadImplementationsInDirectory(PackageScanFilter test, String parent, File location, Set<Class> classes) {
306 File[] files = location.listFiles();
307 StringBuilder builder = null;
308
309 for (File file : files) {
310 builder = new StringBuilder(100);
311 String name = file.getName();
312 if (name != null) {
313 name = name.trim();
314 builder.append(parent).append("/").append(name);
315 String packageOrClass = parent == null ? name : builder.toString();
316
317 if (file.isDirectory()) {
318 loadImplementationsInDirectory(test, packageOrClass, file, classes);
319 } else if (name.endsWith(".class")) {
320 addIfMatching(test, packageOrClass, classes);
321 }
322 }
323 }
324 }
325
326 /**
327 * Finds matching classes within a jar files that contains a folder
328 * structure matching the package structure. If the File is not a JarFile or
329 * does not exist a warning will be logged, but no error will be raised.
330 *
331 * @param test a Test used to filter the classes that are discovered
332 * @param parent the parent package under which classes must be in order to
333 * be considered
334 * @param stream the inputstream of the jar file to be examined for classes
335 * @param urlPath the url of the jar file to be examined for classes
336 */
337 private void loadImplementationsInJar(PackageScanFilter test, String parent, InputStream stream, String urlPath, Set<Class> classes) {
338 JarInputStream jarStream = null;
339 try {
340 jarStream = new JarInputStream(stream);
341
342 JarEntry entry;
343 while ((entry = jarStream.getNextJarEntry()) != null) {
344 String name = entry.getName();
345 if (name != null) {
346 name = name.trim();
347 if (!entry.isDirectory() && name.startsWith(parent) && name.endsWith(".class")) {
348 addIfMatching(test, name, classes);
349 }
350 }
351 }
352 } catch (IOException ioe) {
353 log.error("Could not search jar file '" + urlPath + "' for classes matching criteria: " + test
354 + " due to an IOException: " + ioe.getMessage(), ioe);
355 } finally {
356 ObjectHelper.close(jarStream, urlPath, log);
357 }
358 }
359
360 /**
361 * Add the class designated by the fully qualified class name provided to
362 * the set of resolved classes if and only if it is approved by the Test
363 * supplied.
364 *
365 * @param test the test used to determine if the class matches
366 * @param fqn the fully qualified name of a class
367 */
368 @SuppressWarnings("unchecked")
369 protected void addIfMatching(PackageScanFilter test, String fqn, Set<Class> classes) {
370 try {
371 String externalName = fqn.substring(0, fqn.indexOf('.')).replace('/', '.');
372 Set<ClassLoader> set = getClassLoaders();
373 boolean found = false;
374 for (ClassLoader classLoader : set) {
375 if (log.isTraceEnabled()) {
376 log.trace("Testing for class " + externalName + " matches criteria [" + test + "] using ClassLoader:" + classLoader);
377 }
378 try {
379 Class type = classLoader.loadClass(externalName);
380 if (log.isTraceEnabled()) {
381 log.trace("Loaded the class: " + type + " in classloader: " + classLoader);
382 }
383 if (test.matches(type)) {
384 if (log.isTraceEnabled()) {
385 log.trace("Found class: " + type + " which matches the filter in classloader: " + classLoader);
386 }
387 classes.add(type);
388 }
389 found = true;
390 break;
391 } catch (ClassNotFoundException e) {
392 log.debug("Could not find class '" + fqn + "' in classloader: " + classLoader
393 + ". Reason: " + e, e);
394 } catch (NoClassDefFoundError e) {
395 log.debug("Could not find the class defintion '" + fqn + "' in classloader: " + classLoader
396 + ". Reason: " + e, e);
397 }
398 }
399 if (!found) {
400 log.warn("Could not find class '" + fqn + "' in any classloaders: " + set);
401 }
402 } catch (Exception e) {
403 log.warn("Could not examine class '" + fqn + "' due to a " + e.getClass().getName()
404 + " with message: " + e.getMessage(), e);
405 }
406 }
407
408 }