/**
* Loads the details for the specified NAR. The details will be extracted from the manifest file.
*
* @param narDirectory the nar directory
* @return details about the NAR
* @throws IOException ioe
*/
private static NarDetails getNarDetails(final File narDirectory) throws IOException {
final NarDetails narDetails = new NarDetails();
narDetails.setNarWorkingDirectory(narDirectory);
final File manifestFile = new File(narDirectory, "META-INF/MANIFEST.MF");
try (final FileInputStream fis = new FileInputStream(manifestFile)) {
final Manifest manifest = new Manifest(fis);
final Attributes attributes = manifest.getMainAttributes();
// get the nar details
narDetails.setNarId(attributes.getValue("Nar-Id"));
narDetails.setNarDependencyId(attributes.getValue("Nar-Dependency-Id"));
}
return narDetails;
}
/** Should be called at most once. */
private InitContext load(final File frameworkWorkingDir, final File extensionsWorkingDir)
throws IOException, ClassNotFoundException {
// get the system classloader
final ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();
// find all nar files and create class loaders for them.
final Map<String, ClassLoader> extensionDirectoryClassLoaderLookup = new LinkedHashMap<>();
final Map<String, ClassLoader> narIdClassLoaderLookup = new HashMap<>();
// make sure the nar directory is there and accessible
FileUtils.ensureDirectoryExistAndCanAccess(frameworkWorkingDir);
FileUtils.ensureDirectoryExistAndCanAccess(extensionsWorkingDir);
final List<File> narWorkingDirContents = new ArrayList<>();
final File[] frameworkWorkingDirContents = frameworkWorkingDir.listFiles();
if (frameworkWorkingDirContents != null) {
narWorkingDirContents.addAll(Arrays.asList(frameworkWorkingDirContents));
}
final File[] extensionsWorkingDirContents = extensionsWorkingDir.listFiles();
if (extensionsWorkingDirContents != null) {
narWorkingDirContents.addAll(Arrays.asList(extensionsWorkingDirContents));
}
if (!narWorkingDirContents.isEmpty()) {
final List<NarDetails> narDetails = new ArrayList<>();
// load the nar details which includes and nar dependencies
for (final File unpackedNar : narWorkingDirContents) {
final NarDetails narDetail = getNarDetails(unpackedNar);
// ensure the nar contained an identifier
if (narDetail.getNarId() == null) {
logger.warn("No NAR Id found. Skipping: " + unpackedNar.getAbsolutePath());
continue;
}
// store the nar details
narDetails.add(narDetail);
}
// attempt to locate the jetty nar
ClassLoader jettyClassLoader = null;
for (final Iterator<NarDetails> narDetailsIter = narDetails.iterator();
narDetailsIter.hasNext(); ) {
final NarDetails narDetail = narDetailsIter.next();
// look for the jetty nar
if (JETTY_NAR_ID.equals(narDetail.getNarId())) {
// create the jetty classloader
jettyClassLoader =
createNarClassLoader(narDetail.getNarWorkingDirectory(), systemClassLoader);
// remove the jetty nar since its already loaded
narIdClassLoaderLookup.put(narDetail.getNarId(), jettyClassLoader);
narDetailsIter.remove();
break;
}
}
// ensure the jetty nar was found
if (jettyClassLoader == null) {
throw new IllegalStateException("Unable to locate Jetty bundle.");
}
int narCount;
do {
// record the number of nars to be loaded
narCount = narDetails.size();
// attempt to create each nar class loader
for (final Iterator<NarDetails> narDetailsIter = narDetails.iterator();
narDetailsIter.hasNext(); ) {
final NarDetails narDetail = narDetailsIter.next();
final String narDependencies = narDetail.getNarDependencyId();
// see if this class loader is eligible for loading
ClassLoader narClassLoader = null;
if (narDependencies == null) {
narClassLoader =
createNarClassLoader(narDetail.getNarWorkingDirectory(), jettyClassLoader);
} else if (narIdClassLoaderLookup.containsKey(narDetail.getNarDependencyId())) {
narClassLoader =
createNarClassLoader(
narDetail.getNarWorkingDirectory(),
narIdClassLoaderLookup.get(narDetail.getNarDependencyId()));
}
// if we were able to create the nar class loader, store it and remove the details
if (narClassLoader != null) {
extensionDirectoryClassLoaderLookup.put(
narDetail.getNarWorkingDirectory().getCanonicalPath(), narClassLoader);
narIdClassLoaderLookup.put(narDetail.getNarId(), narClassLoader);
narDetailsIter.remove();
}
}
// attempt to load more if some were successfully loaded this iteration
} while (narCount != narDetails.size());
// see if any nars couldn't be loaded
for (final NarDetails narDetail : narDetails) {
logger.warn(
String.format(
"Unable to resolve required dependency '%s'. Skipping NAR %s",
narDetail.getNarDependencyId(),
narDetail.getNarWorkingDirectory().getAbsolutePath()));
}
}
return new InitContext(
frameworkWorkingDir,
extensionsWorkingDir,
narIdClassLoaderLookup.get(FRAMEWORK_NAR_ID),
new LinkedHashMap<>(extensionDirectoryClassLoaderLookup));
}
