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1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Eclipse Public License, Version 1.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.eclipse.org/org/documents/epl-v10.php
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.ide.eclipse.adt.internal.project;
18 
19 import com.android.ide.eclipse.adt.AdtConstants;
20 import com.android.ide.eclipse.adt.AdtPlugin;
21 import com.android.ide.eclipse.adt.internal.sdk.LoadStatus;
22 import com.android.ide.eclipse.adt.internal.sdk.Sdk;
23 import com.android.sdklib.IAndroidTarget;
24 import com.android.sdklib.IAndroidTarget.IOptionalLibrary;
25 
26 import org.eclipse.core.resources.IMarker;
27 import org.eclipse.core.resources.IProject;
28 import org.eclipse.core.resources.IResource;
29 import org.eclipse.core.runtime.CoreException;
30 import org.eclipse.core.runtime.IPath;
31 import org.eclipse.core.runtime.IProgressMonitor;
32 import org.eclipse.core.runtime.IStatus;
33 import org.eclipse.core.runtime.NullProgressMonitor;
34 import org.eclipse.core.runtime.Path;
35 import org.eclipse.core.runtime.Status;
36 import org.eclipse.core.runtime.jobs.Job;
37 import org.eclipse.jdt.core.ClasspathContainerInitializer;
38 import org.eclipse.jdt.core.IAccessRule;
39 import org.eclipse.jdt.core.IClasspathAttribute;
40 import org.eclipse.jdt.core.IClasspathContainer;
41 import org.eclipse.jdt.core.IClasspathEntry;
42 import org.eclipse.jdt.core.IJavaProject;
43 import org.eclipse.jdt.core.JavaCore;
44 import org.eclipse.jdt.core.JavaModelException;
45 
46 import java.io.File;
47 import java.net.URI;
48 import java.net.URISyntaxException;
49 import java.util.ArrayList;
50 import java.util.HashSet;
51 import java.util.regex.Pattern;
52 
53 /**
54  * Classpath container initializer responsible for binding {@link AndroidClasspathContainer} to
55  * {@link IProject}s. This removes the hard-coded path to the android.jar.
56  */
57 public class AndroidClasspathContainerInitializer extends ClasspathContainerInitializer {
58     /** The container id for the android framework jar file */
59     private final static String CONTAINER_ID =
60         "com.android.ide.eclipse.adt.ANDROID_FRAMEWORK"; //$NON-NLS-1$
61 
62     /** path separator to store multiple paths in a single property. This is guaranteed to not
63      * be in a path.
64      */
65     private final static String PATH_SEPARATOR = "\u001C"; //$NON-NLS-1$
66 
67     private final static String PROPERTY_CONTAINER_CACHE = "androidContainerCache"; //$NON-NLS-1$
68     private final static String PROPERTY_TARGET_NAME = "androidTargetCache"; //$NON-NLS-1$
69     private final static String CACHE_VERSION = "01"; //$NON-NLS-1$
70     private final static String CACHE_VERSION_SEP = CACHE_VERSION + PATH_SEPARATOR;
71 
72     private final static int CACHE_INDEX_JAR = 0;
73     private final static int CACHE_INDEX_SRC = 1;
74     private final static int CACHE_INDEX_DOCS_URI = 2;
75     private final static int CACHE_INDEX_OPT_DOCS_URI = 3;
76     private final static int CACHE_INDEX_ADD_ON_START = CACHE_INDEX_OPT_DOCS_URI;
77 
AndroidClasspathContainerInitializer()78     public AndroidClasspathContainerInitializer() {
79         // pass
80     }
81 
82     /**
83      * Binds a classpath container  to a {@link IClasspathContainer} for a given project,
84      * or silently fails if unable to do so.
85      * @param containerPath the container path that is the container id.
86      * @param project the project to bind
87      */
88     @Override
initialize(IPath containerPath, IJavaProject project)89     public void initialize(IPath containerPath, IJavaProject project) throws CoreException {
90         if (CONTAINER_ID.equals(containerPath.toString())) {
91             JavaCore.setClasspathContainer(new Path(CONTAINER_ID),
92                     new IJavaProject[] { project },
93                     new IClasspathContainer[] { allocateAndroidContainer(project) },
94                     new NullProgressMonitor());
95         }
96     }
97 
98     /**
99      * Creates a new {@link IClasspathEntry} of type {@link IClasspathEntry#CPE_CONTAINER}
100      * linking to the Android Framework.
101      */
getContainerEntry()102     public static IClasspathEntry getContainerEntry() {
103         return JavaCore.newContainerEntry(new Path(CONTAINER_ID));
104     }
105 
106     /**
107      * Checks the {@link IPath} objects against the android framework container id and
108      * returns <code>true</code> if they are identical.
109      * @param path the <code>IPath</code> to check.
110      */
checkPath(IPath path)111     public static boolean checkPath(IPath path) {
112         return CONTAINER_ID.equals(path.toString());
113     }
114 
115     /**
116      * Updates the {@link IJavaProject} objects with new android framework container. This forces
117      * JDT to recompile them.
118      * @param androidProjects the projects to update.
119      * @return <code>true</code> if success, <code>false</code> otherwise.
120      */
updateProjects(IJavaProject[] androidProjects)121     public static boolean updateProjects(IJavaProject[] androidProjects) {
122         try {
123             // Allocate a new AndroidClasspathContainer, and associate it to the android framework
124             // container id for each projects.
125             // By providing a new association between a container id and a IClasspathContainer,
126             // this forces the JDT to query the IClasspathContainer for new IClasspathEntry (with
127             // IClasspathContainer#getClasspathEntries()), and therefore force recompilation of
128             // the projects.
129             int projectCount = androidProjects.length;
130 
131             IClasspathContainer[] containers = new IClasspathContainer[projectCount];
132             for (int i = 0 ; i < projectCount; i++) {
133                 containers[i] = allocateAndroidContainer(androidProjects[i]);
134             }
135 
136             // give each project their new container in one call.
137             JavaCore.setClasspathContainer(
138                     new Path(CONTAINER_ID),
139                     androidProjects, containers, new NullProgressMonitor());
140 
141             return true;
142         } catch (JavaModelException e) {
143             return false;
144         }
145     }
146 
147     /**
148      * Allocates and returns an {@link AndroidClasspathContainer} object with the proper
149      * path to the framework jar file.
150      * @param javaProject The java project that will receive the container.
151      */
allocateAndroidContainer(IJavaProject javaProject)152     private static IClasspathContainer allocateAndroidContainer(IJavaProject javaProject) {
153         final IProject iProject = javaProject.getProject();
154 
155         String markerMessage = null;
156         boolean outputToConsole = true;
157 
158         try {
159             AdtPlugin plugin = AdtPlugin.getDefault();
160 
161             // get the lock object for project manipulation during SDK load.
162             Object lock = plugin.getSdkLockObject();
163             synchronized (lock) {
164                 boolean sdkIsLoaded = plugin.getSdkLoadStatus() == LoadStatus.LOADED;
165 
166                 // check if the project has a valid target.
167                 IAndroidTarget target = null;
168                 if (sdkIsLoaded) {
169                     target = Sdk.getCurrent().getTarget(iProject);
170                 }
171 
172                 // if we are loaded and the target is non null, we create a valid ClassPathContainer
173                 if (sdkIsLoaded && target != null) {
174 
175                     String targetName = target.getClasspathName();
176 
177                     return new AndroidClasspathContainer(
178                             createClasspathEntries(iProject, target, targetName),
179                             new Path(CONTAINER_ID), targetName);
180                 }
181 
182                 // In case of error, we'll try different thing to provide the best error message
183                 // possible.
184                 // Get the project's target's hash string (if it exists)
185                 String hashString = Sdk.getProjectTargetHashString(iProject);
186 
187                 if (hashString == null || hashString.length() == 0) {
188                     // if there is no hash string we only show this if the SDK is loaded.
189                     // For a project opened at start-up with no target, this would be displayed
190                     // twice, once when the project is opened, and once after the SDK has
191                     // finished loading.
192                     // By testing the sdk is loaded, we only show this once in the console.
193                     if (sdkIsLoaded) {
194                         markerMessage = String.format(
195                                 "Project has no target set. Edit the project properties to set one.");
196                     }
197                 } else if (sdkIsLoaded) {
198                     markerMessage = String.format(
199                             "Unable to resolve target '%s'", hashString);
200                 } else {
201                     // this is the case where there is a hashString but the SDK is not yet
202                     // loaded and therefore we can't get the target yet.
203                     // We check if there is a cache of the needed information.
204                     AndroidClasspathContainer container = getContainerFromCache(iProject);
205 
206                     if (container == null) {
207                         // either the cache was wrong (ie folder does not exists anymore), or
208                         // there was no cache. In this case we need to make sure the project
209                         // is resolved again after the SDK is loaded.
210                         plugin.setProjectToResolve(javaProject);
211 
212                         markerMessage = String.format(
213                                 "Unable to resolve target '%s' until the SDK is loaded.",
214                                 hashString);
215 
216                         // let's not log this one to the console as it will happen at every boot,
217                         // and it's expected. (we do keep the error marker though).
218                         outputToConsole = false;
219 
220                     } else {
221                         // we created a container from the cache, so we register the project
222                         // to be checked for cache validity once the SDK is loaded
223                         plugin.setProjectToCheck(javaProject);
224 
225                         // and return the container
226                         return container;
227                     }
228 
229                 }
230 
231                 // return a dummy container to replace the one we may have had before.
232                 // It'll be replaced by the real when if/when the target is resolved if/when the
233                 // SDK finishes loading.
234                 return new IClasspathContainer() {
235                     public IClasspathEntry[] getClasspathEntries() {
236                         return new IClasspathEntry[0];
237                     }
238 
239                     public String getDescription() {
240                         return "Unable to get system library for the project";
241                     }
242 
243                     public int getKind() {
244                         return IClasspathContainer.K_DEFAULT_SYSTEM;
245                     }
246 
247                     public IPath getPath() {
248                         return null;
249                     }
250                 };
251             }
252         } finally {
253             if (markerMessage != null) {
254                 // log the error and put the marker on the project if we can.
255                 if (outputToConsole) {
256                     AdtPlugin.printErrorToConsole(iProject, markerMessage);
257                 }
258 
259                 try {
260                     BaseProjectHelper.addMarker(iProject, AdtConstants.MARKER_TARGET, markerMessage,
261                             -1, IMarker.SEVERITY_ERROR, IMarker.PRIORITY_HIGH);
262                 } catch (CoreException e) {
263                     // In some cases, the workspace may be locked for modification when we
264                     // pass here.
265                     // We schedule a new job to put the marker after.
266                     final String fmessage = markerMessage;
267                     Job markerJob = new Job("Android SDK: Resolving error markers") {
268                         @Override
269                         protected IStatus run(IProgressMonitor monitor) {
270                             try {
271                                 BaseProjectHelper.addMarker(iProject, AdtConstants.MARKER_TARGET,
272                                         fmessage, -1, IMarker.SEVERITY_ERROR,
273                                         IMarker.PRIORITY_HIGH);
274                             } catch (CoreException e2) {
275                                 return e2.getStatus();
276                             }
277 
278                             return Status.OK_STATUS;
279                         }
280                     };
281 
282                     // build jobs are run after other interactive jobs
283                     markerJob.setPriority(Job.BUILD);
284                     markerJob.schedule();
285                 }
286             } else {
287                 // no error, remove potential MARKER_TARGETs.
288                 try {
289                     if (iProject.exists()) {
290                         iProject.deleteMarkers(AdtConstants.MARKER_TARGET, true,
291                                 IResource.DEPTH_INFINITE);
292                     }
293                 } catch (CoreException ce) {
294                     // In some cases, the workspace may be locked for modification when we pass
295                     // here, so we schedule a new job to put the marker after.
296                     Job markerJob = new Job("Android SDK: Resolving error markers") {
297                         @Override
298                         protected IStatus run(IProgressMonitor monitor) {
299                             try {
300                                 iProject.deleteMarkers(AdtConstants.MARKER_TARGET, true,
301                                         IResource.DEPTH_INFINITE);
302                             } catch (CoreException e2) {
303                                 return e2.getStatus();
304                             }
305 
306                             return Status.OK_STATUS;
307                         }
308                     };
309 
310                     // build jobs are run after other interactive jobs
311                     markerJob.setPriority(Job.BUILD);
312                     markerJob.schedule();
313                 }
314             }
315         }
316     }
317 
318     /**
319      * Creates and returns an array of {@link IClasspathEntry} objects for the android
320      * framework and optional libraries.
321      * <p/>This references the OS path to the android.jar and the
322      * java doc directory. This is dynamically created when a project is opened,
323      * and never saved in the project itself, so there's no risk of storing an
324      * obsolete path.
325      * The method also stores the paths used to create the entries in the project persistent
326      * properties. A new {@link AndroidClasspathContainer} can be created from the stored path
327      * using the {@link #getContainerFromCache(IProject)} method.
328      * @param project
329      * @param target The target that contains the libraries.
330      * @param targetName
331      */
332     private static IClasspathEntry[] createClasspathEntries(IProject project,
333             IAndroidTarget target, String targetName) {
334 
335         // get the path from the target
336         String[] paths = getTargetPaths(target);
337 
338         // create the classpath entry from the paths
339         IClasspathEntry[] entries = createClasspathEntriesFromPaths(paths);
340 
341         // paths now contains all the path required to recreate the IClasspathEntry with no
342         // target info. We encode them in a single string, with each path separated by
343         // OS path separator.
344         StringBuilder sb = new StringBuilder(CACHE_VERSION);
345         for (String p : paths) {
346             sb.append(PATH_SEPARATOR);
347             sb.append(p);
348         }
349 
350         // store this in a project persistent property
351         ProjectHelper.saveStringProperty(project, PROPERTY_CONTAINER_CACHE, sb.toString());
352         ProjectHelper.saveStringProperty(project, PROPERTY_TARGET_NAME, targetName);
353 
354         return entries;
355     }
356 
357     /**
358      * Generates an {@link AndroidClasspathContainer} from the project cache, if possible.
359      */
360     private static AndroidClasspathContainer getContainerFromCache(IProject project) {
361         // get the cached info from the project persistent properties.
362         String cache = ProjectHelper.loadStringProperty(project, PROPERTY_CONTAINER_CACHE);
363         String targetNameCache = ProjectHelper.loadStringProperty(project, PROPERTY_TARGET_NAME);
364         if (cache == null || targetNameCache == null) {
365             return null;
366         }
367 
368         // the first 2 chars must match CACHE_VERSION. The 3rd char is the normal separator.
369         if (cache.startsWith(CACHE_VERSION_SEP) == false) {
370             return null;
371         }
372 
373         cache = cache.substring(CACHE_VERSION_SEP.length());
374 
375         // the cache contains multiple paths, separated by a character guaranteed to not be in
376         // the path (\u001C).
377         // The first 3 are for android.jar (jar, source, doc), the rest are for the optional
378         // libraries and should contain at least one doc and a jar (if there are any libraries).
379         // Therefore, the path count should be 3 or 5+
380         String[] paths = cache.split(Pattern.quote(PATH_SEPARATOR));
381         if (paths.length < 3 || paths.length == 4) {
382             return null;
383         }
384 
385         // now we check the paths actually exist.
386         // There's an exception: If the source folder for android.jar does not exist, this is
387         // not a problem, so we skip it.
388         // Also paths[CACHE_INDEX_DOCS_URI] is a URI to the javadoc, so we test it a
389         // bit differently.
390         try {
391             if (new File(paths[CACHE_INDEX_JAR]).exists() == false ||
392                     new File(new URI(paths[CACHE_INDEX_DOCS_URI])).exists() == false) {
393                 return null;
394             }
395 
396             // check the path for the add-ons, if they exist.
397             if (paths.length > CACHE_INDEX_ADD_ON_START) {
398 
399                 // check the docs path separately from the rest of the paths as it's a URI.
400                 if (new File(new URI(paths[CACHE_INDEX_OPT_DOCS_URI])).exists() == false) {
401                     return null;
402                 }
403 
404                 // now just check the remaining paths.
405                 for (int i = CACHE_INDEX_ADD_ON_START + 1; i < paths.length; i++) {
406                     String path = paths[i];
407                     if (path.length() > 0) {
408                         File f = new File(path);
409                         if (f.exists() == false) {
410                             return null;
411                         }
412                     }
413                 }
414             }
415         } catch (URISyntaxException e) {
416             return null;
417         }
418 
419         IClasspathEntry[] entries = createClasspathEntriesFromPaths(paths);
420 
421         return new AndroidClasspathContainer(entries,
422                 new Path(CONTAINER_ID), targetNameCache);
423     }
424 
425     /**
426      * Generates an array of {@link IClasspathEntry} from a set of paths.
427      * @see #getTargetPaths(IAndroidTarget)
428      */
429     private static IClasspathEntry[] createClasspathEntriesFromPaths(String[] paths) {
430         ArrayList<IClasspathEntry> list = new ArrayList<IClasspathEntry>();
431 
432         // First, we create the IClasspathEntry for the framework.
433         // now add the android framework to the class path.
434         // create the path object.
435         IPath android_lib = new Path(paths[CACHE_INDEX_JAR]);
436         IPath android_src = new Path(paths[CACHE_INDEX_SRC]);
437 
438         // create the java doc link.
439         IClasspathAttribute cpAttribute = JavaCore.newClasspathAttribute(
440                 IClasspathAttribute.JAVADOC_LOCATION_ATTRIBUTE_NAME,
441                 paths[CACHE_INDEX_DOCS_URI]);
442 
443         // create the access rule to restrict access to classes in com.android.internal
444         IAccessRule accessRule = JavaCore.newAccessRule(
445                 new Path("com/android/internal/**"), //$NON-NLS-1$
446                 IAccessRule.K_NON_ACCESSIBLE);
447 
448         IClasspathEntry frameworkClasspathEntry = JavaCore.newLibraryEntry(android_lib,
449                 android_src, // source attachment path
450                 null,        // default source attachment root path.
451                 new IAccessRule[] { accessRule },
452                 new IClasspathAttribute[] { cpAttribute },
453                 false // not exported.
454                 );
455 
456         list.add(frameworkClasspathEntry);
457 
458         // now deal with optional libraries
459         if (paths.length >= 5) {
460             String docPath = paths[CACHE_INDEX_OPT_DOCS_URI];
461             int i = 4;
462             while (i < paths.length) {
463                 Path jarPath = new Path(paths[i++]);
464 
465                 IClasspathAttribute[] attributes = null;
466                 if (docPath.length() > 0) {
467                     attributes = new IClasspathAttribute[] {
468                             JavaCore.newClasspathAttribute(
469                                     IClasspathAttribute.JAVADOC_LOCATION_ATTRIBUTE_NAME,
470                                     docPath)
471                     };
472                 }
473 
474                 IClasspathEntry entry = JavaCore.newLibraryEntry(
475                         jarPath,
476                         null, // source attachment path
477                         null, // default source attachment root path.
478                         null,
479                         attributes,
480                         false // not exported.
481                         );
482                 list.add(entry);
483             }
484         }
485 
486         return list.toArray(new IClasspathEntry[list.size()]);
487     }
488 
489     /**
490      * Checks the projects' caches. If the cache was valid, the project is removed from the list.
491      * @param projects the list of projects to check.
492      */
493     public static void checkProjectsCache(ArrayList<IJavaProject> projects) {
494         int i = 0;
495         projectLoop: while (i < projects.size()) {
496             IJavaProject javaProject = projects.get(i);
497             IProject iProject = javaProject.getProject();
498 
499             // check if the project is opened
500             if (iProject.isOpen() == false) {
501                 // remove from the list
502                 // we do not increment i in this case.
503                 projects.remove(i);
504 
505                 continue;
506             }
507 
508             // get the target from the project and its paths
509             IAndroidTarget target = Sdk.getCurrent().getTarget(javaProject.getProject());
510             if (target == null) {
511                 // this is really not supposed to happen. This would mean there are cached paths,
512                 // but default.properties was deleted. Keep the project in the list to force
513                 // a resolve which will display the error.
514                 i++;
515                 continue;
516             }
517 
518             String[] targetPaths = getTargetPaths(target);
519 
520             // now get the cached paths
521             String cache = ProjectHelper.loadStringProperty(iProject, PROPERTY_CONTAINER_CACHE);
522             if (cache == null) {
523                 // this should not happen. We'll force resolve again anyway.
524                 i++;
525                 continue;
526             }
527 
528             String[] cachedPaths = cache.split(Pattern.quote(PATH_SEPARATOR));
529             if (cachedPaths.length < 3 || cachedPaths.length == 4) {
530                 // paths length is wrong. simply resolve the project again
531                 i++;
532                 continue;
533             }
534 
535             // Now we compare the paths. The first 4 can be compared directly.
536             // because of case sensitiveness we need to use File objects
537 
538             if (targetPaths.length != cachedPaths.length) {
539                 // different paths, force resolve again.
540                 i++;
541                 continue;
542             }
543 
544             // compare the main paths (android.jar, main sources, main javadoc)
545             if (new File(targetPaths[CACHE_INDEX_JAR]).equals(
546                             new File(cachedPaths[CACHE_INDEX_JAR])) == false ||
547                     new File(targetPaths[CACHE_INDEX_SRC]).equals(
548                             new File(cachedPaths[CACHE_INDEX_SRC])) == false ||
549                     new File(targetPaths[CACHE_INDEX_DOCS_URI]).equals(
550                             new File(cachedPaths[CACHE_INDEX_DOCS_URI])) == false) {
551                 // different paths, force resolve again.
552                 i++;
553                 continue;
554             }
555 
556             if (cachedPaths.length > CACHE_INDEX_OPT_DOCS_URI) {
557                 // compare optional libraries javadoc
558                 if (new File(targetPaths[CACHE_INDEX_OPT_DOCS_URI]).equals(
559                         new File(cachedPaths[CACHE_INDEX_OPT_DOCS_URI])) == false) {
560                     // different paths, force resolve again.
561                     i++;
562                     continue;
563                 }
564 
565                 // testing the optional jar files is a little bit trickier.
566                 // The order is not guaranteed to be identical.
567                 // From a previous test, we do know however that there is the same number.
568                 // The number of libraries should be low enough that we can simply go through the
569                 // lists manually.
570                 targetLoop: for (int tpi = 4 ; tpi < targetPaths.length; tpi++) {
571                     String targetPath = targetPaths[tpi];
572 
573                     // look for a match in the other array
574                     for (int cpi = 4 ; cpi < cachedPaths.length; cpi++) {
575                         if (new File(targetPath).equals(new File(cachedPaths[cpi]))) {
576                             // found a match. Try the next targetPath
577                             continue targetLoop;
578                         }
579                     }
580 
581                     // if we stop here, we haven't found a match, which means there's a
582                     // discrepancy in the libraries. We force a resolve.
583                     i++;
584                     continue projectLoop;
585                 }
586             }
587 
588             // at the point the check passes, and we can remove the project from the list.
589             // we do not increment i in this case.
590             projects.remove(i);
591         }
592     }
593 
594     /**
595      * Returns the paths necessary to create the {@link IClasspathEntry} for this targets.
596      * <p/>The paths are always in the same order.
597      * <ul>
598      * <li>Path to android.jar</li>
599      * <li>Path to the source code for android.jar</li>
600      * <li>Path to the javadoc for the android platform</li>
601      * </ul>
602      * Additionally, if there are optional libraries, the array will contain:
603      * <ul>
604      * <li>Path to the librairies javadoc</li>
605      * <li>Path to the first .jar file</li>
606      * <li>(more .jar as needed)</li>
607      * </ul>
608      */
609     private static String[] getTargetPaths(IAndroidTarget target) {
610         ArrayList<String> paths = new ArrayList<String>();
611 
612         // first, we get the path for android.jar
613         // The order is: android.jar, source folder, docs folder
614         paths.add(target.getPath(IAndroidTarget.ANDROID_JAR));
615         paths.add(target.getPath(IAndroidTarget.SOURCES));
616         paths.add(AdtPlugin.getUrlDoc());
617 
618         // now deal with optional libraries.
619         IOptionalLibrary[] libraries = target.getOptionalLibraries();
620         if (libraries != null) {
621             // all the optional libraries use the same javadoc, so we start with this
622             String targetDocPath = target.getPath(IAndroidTarget.DOCS);
623             if (targetDocPath != null) {
624                 paths.add(ProjectHelper.getJavaDocPath(targetDocPath));
625             } else {
626                 // we add an empty string, to always have the same count.
627                 paths.add("");
628             }
629 
630             // because different libraries could use the same jar file, we make sure we add
631             // each jar file only once.
632             HashSet<String> visitedJars = new HashSet<String>();
633             for (IOptionalLibrary library : libraries) {
634                 String jarPath = library.getJarPath();
635                 if (visitedJars.contains(jarPath) == false) {
636                     visitedJars.add(jarPath);
637                     paths.add(jarPath);
638                 }
639             }
640         }
641 
642         return paths.toArray(new String[paths.size()]);
643     }
644 }
645