/**
* Returns an input stream for reading the specified remote resource.<br>
*
* @param name the resource name
* @return an input stream for reading the resource, or {@code null} if the resource could not be
* found
*/
protected InputStream getRemoteResourceAsStream(String name) {
try {
log.fine("Trying to load resource " + name + " from the class provider.");
ClassLoaderRequest request = new ClassLoaderRequest(name);
ClassLoaderResponse response = (ClassLoaderResponse) mq.requestResponse(request, id);
ClassLoaderOffer offer = response.getAcceptedOffer();
log.fine("As a response to loading " + name + " received offer " + offer);
// If a remote resource was found, store it in the cache and return it
if (offer != null && offer.hasFiles()) {
cache.registerOffer(offer);
useOffer(null, offer);
String fileLocation = cache.getFileLocation(name, offer.getName());
// we could have got null because of wrong platform-dependent
// separator used by user. Let's try again with fixed one.
// (linux can use windows-style separators for escaping,
// therefore it's not a good idea to always replace them)
if (fileLocation == null)
fileLocation =
cache.getFileLocation(
name.replace('/', File.separatorChar).replace('\\', File.separatorChar),
offer.getName());
if (fileLocation != null) {
return new FileInputStream(fileLocation);
} else
log.warning(
"The received offer does not contain the file requested or the file could not be stored: cache returned NULL");
}
} catch (JMSException | TimeoutException e) {
throw new JCloudScaleException(e);
} catch (FileNotFoundException e) {
// Ignore
}
return null;
}
private Class<?> useOffer(String className, ClassLoaderOffer offer) {
try {
if (offer == null) {
log.severe(
"Failed to use code to resolve class " + className + " as there's no offer provided.");
return null;
}
Class<?> requestedClass = null;
// we go through all files in this offer and register them within this classloader
for (ClassLoaderFile file : offer.getFiles()) {
switch (file.getType()) {
case CLASS:
if (super.findLoadedClass(file.getName()) != null) {
log.info("Attempting to load already loaded class: " + file.getName());
continue;
}
byte[] bytecode = file.getContent();
if (bytecode
== null) // if there's no content in transmitted file, we have to get it from the
// cache.
bytecode = cache.getClassBytecode(file.getName(), offer.getName());
if (bytecode == null) {
log.severe(
"Failed to define class " + file.getName() + " from offer " + offer.getName());
continue;
}
Class<?> clazz = defineClass(file.getName(), bytecode, 0, bytecode.length);
if (clazz.getName().equals(className)) requestedClass = clazz;
break;
case JAR:
String path = cache.getFileLocation(file.getName(), offer.getName());
if (path == null) {
log.severe(
"Failed to find file " + file.getName() + " from package " + offer.getName());
continue;
}
try {
addURL(new File(path).toURI().toURL());
} catch (MalformedURLException e) {
log.severe("Exception while registering file " + path + ":" + e.toString());
continue;
}
break;
case ROFILE:
// case RWFILE:
if (!cache.deployFile(file.getName(), offer.getName()))
log.severe(
"Failed to deploy required file "
+ file.getName()
+ ". Failed to write file to disk.");
break;
default:
log.severe(
"Unexpected type of file ("
+ file.getType()
+ ") provided in the offer. skipping.");
}
}
if (className != null
&& requestedClass
== null) { // this can happen as it is possible that the required class is in the jar
byte[] bytecode = cache.getClassBytecode(className, offer.getName());
if (bytecode != null) requestedClass = defineClass(className, bytecode, 0, bytecode.length);
}
usedOffers.add(offer.getName()); // if everything is fine, we add this offer as used.
return requestedClass;
} catch (Throwable ex) {
log.severe(
"Failed to use offer "
+ (offer != null ? offer.getName() : "NULL offer ")
+ " from the cache. Removing the offer and failing...");
if (offer != null) cache.removeOfferByName(offer.getName());
throw ex;
}
}
