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;
}
}
/** Checks whether list of files contains file with the same name as proposed. */
private boolean containsFile(List<ClassLoaderFile> filesList, ClassLoaderFile otherFile) {
for (ClassLoaderFile file : filesList)
if (file.getName().equals(otherFile.getName())) return true;
return false;
}