protected Listener getListener(Container.Entry entry) {
URI key = entry.getUri();
if (cache.containsKey(key)) {
return cache.get(key);
} else {
Listener listener;
try (InputStream inputStream = entry.getInputStream()) {
ANTLRJavaParser.parse(new ANTLRInputStream(inputStream), listener = new Listener(entry));
} catch (IOException ignore) {
listener = null;
}
cache.put(key, listener);
return listener;
}
}
/**
* Gets registered object from CacheMap. The algorithm used to look up is <br>
* 1. First check for exact match with clazz and context.<br>
* 2. If didn't find, look for interfaces that clazz implements using the exact context.<br>
* 3. If still didn't find, look for super class of clazz using the exact context. <br>
* 4. If still didn't find, using the exact clazz with default context.<br>
* 5. If still didn't find, return null.<br>
* If found a match in step 1, 2, 3 or 4, it will return the registered object immediately.
*
* @param clazz the class which is used as the primary key.
* @param context the context which is used as the secondary key. This parameter could be null in
* which case the default context is used.
* @return registered object the object associated with the class and the context.
*/
public T getRegisteredObject(Class<?> clazz, K context) {
if (clazz == null) {
return null;
}
Cache<K, T> cache = getCache(clazz);
if (cache == null || !cache.containsKey(context)) {
List<Class<?>> classesToSearch = new ArrayList<>();
classesToSearch.add(clazz);
if (TypeUtils.isPrimitive(clazz)) {
classesToSearch.add(TypeUtils.convertPrimitiveToWrapperType(clazz));
} else if (TypeUtils.isPrimitiveWrapper(clazz)) {
classesToSearch.add(TypeUtils.convertWrapperToPrimitiveType(clazz));
}
// Direct super interfaces, recursively
addAllInterfaces(classesToSearch, clazz);
Class<?> superClass = clazz;
// Direct super class, recursively
while (!superClass.isInterface()) {
superClass = superClass.getSuperclass();
if (superClass != null) {
classesToSearch.add(superClass);
addAllInterfaces(classesToSearch, superClass);
} else {
break;
}
}
if (!classesToSearch.contains(Object.class)) {
classesToSearch.add(Object.class); // use Object as default fallback.
}
// search to match context first
for (Class<?> c : classesToSearch) {
Cache<K, T> cacheForClass = getCache(c);
if (cacheForClass != null) {
T object = cacheForClass.getObject(context);
if (object != null) {
return object;
}
}
}
// fall back to default context
if (!_defaultContext.equals(context)) {
for (Class<?> c : classesToSearch) {
Cache<K, T> cacheForClass = getCache(c);
if (cacheForClass != null) {
T object = cacheForClass.getObject(_defaultContext);
if (object != null) {
return object;
}
}
}
}
}
if (cache != null) {
T object = cache.getObject(context);
if (object == null && !_defaultContext.equals(context)) {
return getRegisteredObject(clazz, _defaultContext);
}
if (object != null) {
return object;
}
}
return null;
}