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1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.sling.launchpad.base.shared;
20
21 import java.beans.Introspector;
22 import java.io.File;
23 import java.io.FileFilter;
24 import java.io.FileOutputStream;
25 import java.io.IOException;
26 import java.io.InputStream;
27 import java.io.OutputStream;
28 import java.net.JarURLConnection;
29 import java.net.MalformedURLException;
30 import java.net.URI;
31 import java.net.URL;
32 import java.net.URLConnection;
33 import java.util.ArrayList;
34 import java.util.Collections;
35 import java.util.Date;
36 import java.util.List;
37 import java.util.jar.JarFile;
38
39 import org.apache.sling.commons.osgi.bundleversion.BundleVersionInfo;
40 import org.apache.sling.commons.osgi.bundleversion.FileBundleVersionInfo;
41
42 /**
43 * The <code>Loader</code> class provides utility methods for the actual
44 * launchers to help launching the framework.
45 */
46 public class Loader {
47
48 /**
49 * The Sling home folder set by the constructor
50 */
51 private final File slingHome;
52
53 /**
54 * Creates a loader instance to load from the given Sling home folder.
55 * Besides ensuring the existence of the Sling home folder, the constructor
56 * also removes all but the most recent launcher JAR files from the Sling
57 * home folder (thus cleaning up from previous upgrades).
58 *
59 * @param slingHome The Sling home folder. If this is <code>null</code> the
60 * default value {@link SharedConstants#SLING_HOME_DEFAULT} is
61 * assumed.
62 * @throws IllegalArgumentException If the Sling home folder exists but is
63 * not a directory or if the Sling home folder cannot be
64 * created.
65 */
66 public Loader(final String slingHome) throws IllegalArgumentException {
67 this.slingHome = getSlingHomeFile(slingHome);
68 removeOldLauncherJars();
69 }
70
71 /**
72 * Creates an URLClassLoader from a _launcher JAR_ file in the given
73 * slingHome directory and loads and returns the launcher class identified
74 * by the launcherClassName.
75 *
76 * @param launcherClassName The fully qualified name of a class implementing
77 * the Launcher interface. This class must have a public
78 * constructor taking no arguments.
79 * @return the Launcher instance loaded from the newly created classloader
80 * @throws NullPointerException if launcherClassName is null
81 * @throws IllegalArgumentException if the launcherClassName cannot be
82 * instantiated. The cause of the failure is contained as the
83 * cause of the exception.
84 */
85 public Object loadLauncher(String launcherClassName) {
86
87 final File launcherJarFile = getLauncherJarFile();
88 info("Loading launcher class " + launcherClassName + " from " + launcherJarFile.getName());
89 if (!launcherJarFile.canRead()) {
90 throw new IllegalArgumentException("Sling Launcher JAR "
91 + launcherJarFile + " is not accessible");
92 }
93
94 final ClassLoader loader;
95 try {
96 loader = new LauncherClassLoader(launcherJarFile);
97 } catch (MalformedURLException e) {
98 throw new IllegalArgumentException(
99 "Cannot create an URL from the Sling Launcher JAR path name", e);
100 }
101
102 try {
103 final Class<?> launcherClass = loader.loadClass(launcherClassName);
104 return launcherClass.newInstance();
105 } catch (ClassNotFoundException cnfe) {
106 throw new IllegalArgumentException("Cannot find class "
107 + launcherClassName + " in " + launcherJarFile, cnfe);
108 } catch (InstantiationException e) {
109 throw new IllegalArgumentException(
110 "Cannot instantiate launcher class " + launcherClassName, e);
111 } catch (IllegalAccessException e) {
112 throw new IllegalArgumentException(
113 "Cannot access constructor of class " + launcherClassName, e);
114 }
115 }
116
117 /**
118 * Tries to remove as many traces of class loaded by the framework from the
119 * Java VM as possible. Most notably the following traces are removed:
120 * <ul>
121 * <li>JavaBeans property caches
122 * <li>Close the Launcher Jar File (if opened by the platform)
123 * </ul>
124 * <p>
125 * This method must be called when the notifier is called.
126 *
127 */
128 public void cleanupVM() {
129
130 // ensure the JavaBeans introspector lets go of any classes it
131 // may haved cached after introspection
132 Introspector.flushCaches();
133
134 // if sling home is set, check whether we have to close the
135 // launcher JAR JarFile, which might be cached in the platform
136 closeLauncherJarFile(getLauncherJarFile());
137 }
138
139 /**
140 * Copies the contents of the launcher JAR as indicated by the URL to the
141 * sling home directory. If the existing file is is a more recent bundle version
142 * than the supplied launcher JAR file, it is is not replaced.
143 *
144 * @return <code>true</code> if the launcher JAR file has been installed or
145 * updated, <code>false</code> otherwise.
146 * @throws IOException If an error occurrs transferring the contents
147 */
148 public boolean installLauncherJar(URL launcherJar) throws IOException {
149 final File currentLauncherJarFile = getLauncherJarFile();
150
151 // Copy the new launcher jar to a temporary file, and
152 // extract bundle version info
153 final URLConnection launcherJarConn = launcherJar.openConnection();
154 launcherJarConn.setUseCaches(false);
155 final File tmp = new File(slingHome, "Loader_tmp_" + System.currentTimeMillis() + SharedConstants.LAUNCHER_JAR_REL_PATH);
156 spool(launcherJarConn.getInputStream(), tmp);
157 final FileBundleVersionInfo newVi = new FileBundleVersionInfo(tmp);
158 boolean installNewLauncher = true;
159
160 try {
161 if(!newVi.isBundle()) {
162 throw new IllegalArgumentException("New launcher jar is not a bundle, cannot get version info:" + launcherJar);
163 }
164
165 // Compare versions to decide whether to use the existing or new launcher jar
166 if (currentLauncherJarFile.exists()) {
167 final FileBundleVersionInfo currentVi = new FileBundleVersionInfo(currentLauncherJarFile);
168 if(!currentVi.isBundle()) {
169 throw new IllegalArgumentException("Existing launcher jar is not a bundle, cannot get version info:"
170 + currentLauncherJarFile.getAbsolutePath());
171 }
172
173 String info = null;
174 if(currentVi.compareTo(newVi) == 0) {
175 info = "up to date";
176 installNewLauncher = false;
177 } else if(currentVi.compareTo(newVi) > 0) {
178 info = "more recent than ours";
179 installNewLauncher = false;
180 }
181
182 if(info != null) {
183 info("Existing launcher is " + info + ", using it: "
184 + getBundleInfo(currentVi) + " (" + currentLauncherJarFile.getName() + ")");
185 }
186 }
187
188 if(installNewLauncher) {
189 final File f = new File(tmp.getParentFile(), SharedConstants.LAUNCHER_JAR_REL_PATH + "." + System.currentTimeMillis());
190 if(!tmp.renameTo(f)) {
191 throw new IllegalStateException("Failed to rename " + tmp.getName() + " to " + f.getName());
192 }
193 info("Installing new launcher: " + launcherJar + ", " + getBundleInfo(newVi) + " (" + f.getName() + ")");
194 }
195 } finally {
196 if(tmp.exists()) {
197 tmp.delete();
198 }
199 }
200
201 return installNewLauncher;
202 }
203
204 /** Return relevant bundle version info for logging */
205 static String getBundleInfo(BundleVersionInfo<?> v) {
206 final StringBuilder sb = new StringBuilder();
207 sb.append(v.getVersion());
208 if(v.isSnapshot()) {
209 sb.append(", Last-Modified:");
210 sb.append(new Date(v.getBundleLastModified()));
211 }
212 return sb.toString();
213 }
214
215 /**
216 * Removes old candidate launcher JAR files leaving the most recent one as
217 * the launcher JAR file to use on next Sling startup.
218 *
219 * @param slingHome The Sling home directory location containing the
220 * candidate launcher JAR files.
221 */
222 private void removeOldLauncherJars() {
223 final File[] launcherJars = getLauncherJarFiles();
224 if (launcherJars != null && launcherJars.length > 0) {
225
226 // Remove all files except current one
227 final File current = getLauncherJarFile();
228 for(File f : launcherJars) {
229 if(f.getAbsolutePath().equals(current.getAbsolutePath())) {
230 continue;
231 }
232 String versionInfo = null;
233 try {
234 FileBundleVersionInfo vi = new FileBundleVersionInfo(f);
235 versionInfo = getBundleInfo(vi);
236 } catch(IOException ignored) {
237 }
238 info("Deleting obsolete launcher jar: " + f.getName() + ", " + versionInfo);
239 f.delete();
240 }
241
242 // And ensure the current file has the standard launcher name
243 if (!SharedConstants.LAUNCHER_JAR_REL_PATH.equals(current.getName())) {
244 info("Renaming current launcher jar " + current.getName()
245 + " to " + SharedConstants.LAUNCHER_JAR_REL_PATH);
246 File launcherFileName = new File(
247 current.getParentFile(),
248 SharedConstants.LAUNCHER_JAR_REL_PATH);
249 current.renameTo(launcherFileName);
250 }
251 }
252 }
253
254 /**
255 * Spools the contents of the input stream to the given file replacing the
256 * contents of the file with the contents of the input stream. When this
257 * method returns, the input stream is guaranteed to be closed.
258 *
259 * @throws IOException If an error occurrs reading or writing the input
260 * stream contents.
261 */
262 public static void spool(InputStream ins, File destFile) throws IOException {
263 OutputStream out = null;
264 try {
265 out = new FileOutputStream(destFile);
266 byte[] buf = new byte[8192];
267 int rd;
268 while ((rd = ins.read(buf)) >= 0) {
269 out.write(buf, 0, rd);
270 }
271 } finally {
272 if (ins != null) {
273 try {
274 ins.close();
275 } catch (IOException ignore) {
276 }
277 }
278 if (out != null) {
279 try {
280 out.close();
281 } catch (IOException ignore) {
282 }
283 }
284 }
285 }
286
287 // ---------- internal helper
288
289 /**
290 * Returns a <code>File</code> object representing the Launcher JAR file
291 * found in the sling home folder.
292 */
293 private File getLauncherJarFile() {
294 File result = null;
295 final File[] launcherJars = getLauncherJarFiles();
296 if (launcherJars == null || launcherJars.length == 0) {
297
298 // return a non-existing file naming the desired primary name
299 result = new File(slingHome,
300 SharedConstants.LAUNCHER_JAR_REL_PATH);
301
302 } else {
303 // last file is the most recent one, use it
304 result = launcherJars[launcherJars.length - 1];
305 }
306
307 return result;
308 }
309
310 /**
311 * Returns all files in the <code>slingHome</code> directory which may be
312 * considered as launcher JAR files, sorted based on their bundle version
313 * information, most recent last. These files all start with the
314 * {@link SharedConstants#LAUNCHER_JAR_REL_PATH}. This list may be empty if
315 * the launcher JAR file has not been installed yet.
316 *
317 * @param slingHome The sling home directory where the launcher JAR files
318 * are stored
319 * @return The list of candidate launcher JAR files, which may be empty.
320 * <code>null</code> is returned if an IO error occurs trying to
321 * list the files.
322 */
323 private File[] getLauncherJarFiles() {
324 // Get list of files with names starting with our prefix
325 final File[] rawList = slingHome.listFiles(new FileFilter() {
326 public boolean accept(File pathname) {
327 return pathname.isFile()
328 && pathname.getName().startsWith(
329 SharedConstants.LAUNCHER_JAR_REL_PATH);
330 }
331 });
332
333 // Keep only those which have valid Bundle headers, and
334 // sort them according to the bundle version numbers
335 final List<FileBundleVersionInfo> list = new ArrayList<FileBundleVersionInfo>();
336 for(File f : rawList) {
337 FileBundleVersionInfo fvi = null;
338 try {
339 fvi = new FileBundleVersionInfo(f);
340 } catch(IOException ioe) {
341 // Cannot read bundle info from jar file - should never happen??
342 throw new IllegalStateException("Cannot read bundle information from loader file " + f.getAbsolutePath());
343 }
344 if(fvi.isBundle()) {
345 list.add(fvi);
346 }
347 }
348 Collections.sort(list);
349 final File [] result = new File[list.size()];
350 int i = 0;
351 for(FileBundleVersionInfo fvi : list) {
352 result[i++] = fvi.getSource();
353 }
354 return result;
355 }
356
357 /**
358 * Returns the <code>slingHome</code> path as a directory. If the directory
359 * does not exist it is created. If creation fails or if
360 * <code>slingHome</code> exists but is not a directory a
361 * <code>IllegalArgumentException</code> is thrown.
362 *
363 * @param slingHome The sling home directory where the launcher JAR files
364 * are stored
365 * @return The Sling home directory
366 * @throws IllegalArgumentException if <code>slingHome</code> exists and is
367 * not a directory or cannot be created as a directory.
368 */
369 private static File getSlingHomeFile(String slingHome) {
370 if (slingHome == null) {
371 slingHome = SharedConstants.SLING_HOME_DEFAULT;
372 }
373
374 File slingDir = new File(slingHome).getAbsoluteFile();
375 if (slingDir.exists()) {
376 if (!slingDir.isDirectory()) {
377 throw new IllegalArgumentException("Sling Home " + slingDir
378 + " exists but is not a directory");
379 }
380 } else if (!slingDir.mkdirs()) {
381 throw new IllegalArgumentException("Sling Home " + slingDir
382 + " cannot be created as a directory");
383 }
384
385 return slingDir;
386 }
387
388 private static void closeLauncherJarFile(final File launcherJar) {
389 try {
390 final URI launcherJarUri = launcherJar.toURI();
391 final URL launcherJarRoot = new URL("jar:" + launcherJarUri + "!/");
392 final URLConnection conn = launcherJarRoot.openConnection();
393 if (conn instanceof JarURLConnection) {
394 final JarFile jarFile = ((JarURLConnection) conn).getJarFile();
395 jarFile.close();
396 }
397 } catch (Exception e) {
398 // better logging here
399 }
400 }
401
402 /** Meant to be overridden to display or log info */
403 protected void info(String msg) {
404 }
405 }