/**
* Resolves a reference to a local or remote file or element. If the link refers to an element in
* the current document, this method returns that element. If the link refers to a remote
* document, this method will initiate asynchronous retrieval of the document, and return a URL of
* the downloaded document in the file cache, if it is available locally. If the link identifies a
* COLLADA document, the document will be returned as a parsed ColladaRoot.
*
* @param link the address of the document or element to resolve. This may be a full URL, a URL
* fragment that identifies an element in the current document ("#myElement"), or a URL and a
* fragment identifier ("http://server.com/model.dae#myElement").
* @return the requested element, or null if the element is not found.
* @throws IllegalArgumentException if the address is null.
*/
public Object resolveReference(String link) {
if (link == null) {
String message = Logging.getMessage("nullValue.DocumentSourceIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
try {
String[] linkParts = link.split("#");
String linkBase = linkParts[0];
String linkRef = linkParts.length > 1 ? linkParts[1] : null;
// See if it's a reference to an internal element.
if (WWUtil.isEmpty(linkBase) && !WWUtil.isEmpty(linkRef)) return this.getItemByID(linkRef);
// Interpret the path relative to the current document.
String path = this.getSupportFilePath(linkBase);
if (path == null) path = linkBase;
// See if it's an already found and parsed COLLADA file.
Object o = WorldWind.getSessionCache().get(path);
if (o != null && o instanceof ColladaRoot)
return linkRef != null ? ((ColladaRoot) o).getItemByID(linkRef) : o;
URL url = WWIO.makeURL(path);
if (url == null) {
// See if the reference can be resolved to a local file.
o = this.resolveLocalReference(path, linkRef);
}
// If we didn't find a local file, treat it as a remote reference.
if (o == null) o = this.resolveRemoteReference(path, linkRef);
if (o != null) return o;
// If the reference was not resolved as a remote reference, look for a local element
// identified by the
// reference string. This handles the case of malformed internal references that omit the #
// sign at the
// beginning of the reference.
return this.getItemByID(link);
} catch (Exception e) {
String message = Logging.getMessage("generic.UnableToResolveReference", link);
Logging.logger().warning(message);
}
return null;
}
/**
* Creates a Collada root for an untyped source. The source must be either a {@link File} or a
* {@link String} identifying either a file path or a {@link URL}. Null is returned if the source
* type is not recognized.
*
* @param docSource either a {@link File} or a {@link String} identifying a file path or {@link
* URL}.
* @return a new {@link ColladaRoot} for the specified source, or null if the source type is not
* supported.
* @throws IllegalArgumentException if the source is null.
* @throws IOException if an error occurs while reading the source.
*/
public static ColladaRoot create(Object docSource) throws IOException {
if (docSource == null) {
String message = Logging.getMessage("nullValue.DocumentSourceIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
if (docSource instanceof File) {
return new ColladaRoot((File) docSource);
} else if (docSource instanceof URL) {
return new ColladaRoot((URL) docSource);
} else if (docSource instanceof String) {
File file = new File((String) docSource);
if (file.exists()) return new ColladaRoot(file);
URL url = WWIO.makeURL(docSource);
if (url != null) return new ColladaRoot(url);
} else if (docSource instanceof InputStream) {
return new ColladaRoot((InputStream) docSource);
}
return null;
}