/**
* Get a Entry from the cache. Get either a valid entry object or create a new one if possible.
*
* @param pathInContext The key into the cache
* @return The entry matching <code>pathInContext</code>, or a new entry if no matching entry was
* found. If the content exists but is not cachable, then a {@link ResourceAsHttpContent}
* instance is return. If the resource does not exist, then null is returned.
* @throws IOException Problem loading the resource
*/
public HttpContent lookup(String pathInContext) throws IOException {
// Is the content in this cache?
Content content = _cache.get(pathInContext);
if (content != null && (content).isValid()) return content;
// try loading the content from our factory.
Resource resource = _factory.getResource(pathInContext);
HttpContent loaded = load(pathInContext, resource);
if (loaded != null) return loaded;
// Is the content in the parent cache?
if (_parent != null) {
HttpContent httpContent = _parent.lookup(pathInContext);
if (httpContent != null) return httpContent;
}
return null;
}