/**
* Resolves a reference to a local element identified by address and identifier, where {@code
* linkBase} identifies a document, including the current document, and {@code linkRef} is the id
* of the desired element.
*
* <p>If {@code linkBase} refers to a local COLLADA file and {@code linkRef} is non-null, the
* return value is the element identified by {@code linkRef}. If {@code linkRef} is null, the
* return value is a parsed {@link ColladaRoot} for the COLLADA file identified by {@code
* linkBase}. Otherwise, {@code linkBase} is returned.
*
* @param linkBase the address of the document containing the requested element.
* @param linkRef the element's identifier.
* @return the requested element, or null if the element is not found.
* @throws IllegalArgumentException if the address is null.
*/
protected Object resolveLocalReference(String linkBase, String linkRef) {
if (linkBase == null) {
String message = Logging.getMessage("nullValue.DocumentSourceIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
try {
File file = new File(linkBase);
if (!file.exists()) return null;
// Determine whether the file is a COLLADA document. If not, just return the file path.
if (!WWIO.isContentType(file, ColladaConstants.COLLADA_MIME_TYPE))
return file.toURI().toString();
// Attempt to open and parse the COLLADA file.
ColladaRoot refRoot = ColladaRoot.createAndParse(file);
// An exception is thrown if parsing fails, so no need to check for null.
// Add the parsed file to the session cache so it doesn't have to be parsed again.
WorldWind.getSessionCache().put(linkBase, refRoot);
// Now check the newly opened COLLADA file for the referenced item, if a reference was
// specified.
if (linkRef != null) return refRoot.getItemByID(linkRef);
else return refRoot;
} catch (Exception e) {
String message =
Logging.getMessage("generic.UnableToResolveReference", linkBase + "/" + linkRef);
Logging.logger().warning(message);
return null;
}
}
/**
* Creates and parses 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 createAndParse(Object docSource)
throws IOException, XMLStreamException {
ColladaRoot colladaRoot = ColladaRoot.create(docSource);
if (colladaRoot == null) {
String message =
Logging.getMessage(
"generic.UnrecognizedSourceTypeOrUnavailableSource", docSource.toString());
throw new IllegalArgumentException(message);
}
colladaRoot.parse();
return colladaRoot;
}
/**
* Open and parse the specified file expressed as a file: URL..
*
* @param url the URL of the file to open, expressed as a URL with a scheme of "file".
* @param linkBase the original address of the document if the file is a retrieved and cached
* file.
* @return A {@code ColladaRoot} representing the file's COLLADA contents.
* @throws IOException if an I/O error occurs during opening and parsing.
* @throws XMLStreamException if a server parsing error is encountered.
*/
protected ColladaRoot parseCachedColladaFile(URL url, String linkBase)
throws IOException, XMLStreamException {
ColladaDoc colladaDoc;
InputStream refStream = url.openStream();
colladaDoc = new ColladaInputStream(refStream, WWIO.makeURI(linkBase));
try {
ColladaRoot refRoot = new ColladaRoot(colladaDoc);
refRoot.parse(); // also closes the URL's stream
return refRoot;
} catch (XMLStreamException e) {
refStream.close(); // parsing failed, so explicitly close the stream
throw e;
}
}
/**
* Resolves a reference to a remote element identified by address and identifier, where {@code
* linkBase} identifies a remote document, and {@code linkRef} is the id of the desired element.
* This method retrieves resources asynchronously using the {@link
* gov.nasa.worldwind.cache.FileStore}.
*
* <p>The return value is null if the file is not yet available in the FileStore. If {@code
* linkBase} refers to a COLLADA file and {@code linkRef} is non-null, the return value is the
* element identified by {@code linkRef}. If {@code linkBase} refers to a COLLADA file and {@code
* linkRef} is null, the return value is a parsed {@link ColladaRoot} for the COLLADA file
* identified by {@code linkBase}. Otherwise the return value is a {@link URL} to the file in the
* file cache.
*
* @param linkBase the address of the document containing the requested element.
* @param linkRef the element's identifier.
* @return URL to the requested file, parsed ColladaRoot, or COLLADA element. Returns null if the
* document is not yet available in the FileStore.
* @throws IllegalArgumentException if the {@code linkBase} is null.
*/
public Object resolveRemoteReference(String linkBase, String linkRef) {
if (linkBase == null) {
String message = Logging.getMessage("nullValue.DocumentSourceIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
try {
// See if it's in the cache. If not, requestFile will start another thread to retrieve it and
// return null.
URL url = WorldWind.getDataFileStore().requestFile(linkBase);
if (url == null) return null;
// It's in the cache. If it's a COLLADA file try to parse it so we can search for the
// specified reference.
// If it's not COLLADA, just return the url for the cached file.
String contentType = WorldWind.getDataFileStore().getContentType(linkBase);
if (contentType == null) {
String suffix = WWIO.getSuffix(linkBase.split(";")[0]); // strip of trailing garbage
if (!WWUtil.isEmpty(suffix)) contentType = WWIO.makeMimeTypeForSuffix(suffix);
}
if (!this.canParseContentType(contentType)) return url;
// If the file is a COLLADA document, attempt to open it. We can't open it as a File with
// createAndParse
// because the ColladaRoot that will be created needs to have the remote address in order to
// resolve any
// relative references within it.
ColladaRoot refRoot = this.parseCachedColladaFile(url, linkBase);
// Add the parsed file to the session cache so it doesn't have to be parsed again.
WorldWind.getSessionCache().put(linkBase, refRoot);
// Now check the newly opened COLLADA file for the referenced item, if a reference was
// specified.
if (linkRef != null) return refRoot.getItemByID(linkRef);
else return refRoot;
} catch (Exception e) {
String message =
Logging.getMessage("generic.UnableToResolveReference", linkBase + "/" + linkRef);
Logging.logger().warning(message);
return null;
}
}