/**
* Convert a Mulgara Value to a Jena graph node.
*
* @param obj The Mulgara value to convert.
* @return A new Jena graph node.
*/
static Node o2n(org.jrdf.graph.Node obj) {
if (obj == null) return Node.ANY;
// testing for org.jrdf.graph.URIReference
if (obj.isURIReference()) {
URIReference uRef = (URIReference) obj;
if (skolemizedBlankNodes) {
String x = uRef.getURI().toString();
if (x.startsWith(bNodeScheme)) {
x = x.substring(bNodeScheme.length());
Node n = Node.createAnon(new AnonId(x));
return n;
}
}
return Node.createURI(uRef.getURI().toString());
}
// testing for org.jrdf.graph.Literal
if (obj.isLiteral()) {
Literal literal = (Literal) obj;
if (literal.getDatatypeURI() != null) {
RDFDatatype type =
TypeMapper.getInstance().getSafeTypeByName(literal.getDatatypeURI().toString());
return Node.createLiteral(literal.getLexicalForm(), null, type);
}
return Node.createLiteral(literal.getLexicalForm(), literal.getLanguage(), null);
}
if (obj.isBlankNode()) {
BlankNodeImpl b = (BlankNodeImpl) obj;
// check if this was a Jena-allocated node
Node jenaNode = valuesToNodes.get(b);
// if not known, then create a Jena node from the Mulgara ID
return jenaNode != null ? jenaNode : Node.createAnon(new AnonId(b.getID()));
}
throw new RuntimeException("Can't convert to Jena Node : " + obj);
}
/** Insert or delete RDF statements in a model at a URL. */
public void modifyModel(long model, Statements statements, boolean occurs)
throws ResolverException {
if (logger.isDebugEnabled()) {
logger.debug("Modify URL model " + model);
}
try {
FullTextStringIndex stringIndex = getFullTextStringIndex(model);
statements.beforeFirst();
while (statements.next()) {
Node subjectNode = resolverSession.globalize(statements.getSubject());
// Do not insert the triple if it contains a blank node in subject.
if (subjectNode instanceof BlankNode) {
if (logger.isInfoEnabled()) {
logger.info(statements.getSubject() + " is blank node; ignoring Lucene insert.");
}
continue;
}
Node predicateNode = resolverSession.globalize(statements.getPredicate());
Node objectNode = resolverSession.globalize(statements.getObject());
// Get the subject's string value.
String subject = ((URIReference) subjectNode).getURI().toString();
// Predicates can only ever be URIReferences.
String predicate = ((URIReference) predicateNode).getURI().toString();
if (objectNode instanceof URIReference) {
URIReference objectURI = (URIReference) objectNode;
String resource = objectURI.getURI().toString();
try {
// Assert or deny the statement in the Lucene model
if (occurs) {
InputStream input = null;
Reader reader = null;
try {
// Connect to the resource's content
URLConnection connection = objectURI.getURI().toURL().openConnection();
String contentType = connection.getContentType();
if (logger.isDebugEnabled()) {
logger.debug("Content type of resource is " + contentType);
}
MimeType contentMimeType;
try {
contentMimeType = new MimeType(contentType);
} catch (MimeTypeParseException e) {
logger.warn("\"" + contentType + "\" didn't parse as MIME type", e);
try {
contentMimeType = new MimeType("content", "unknown");
} catch (MimeTypeParseException em) {
throw new ResolverException("Failed to create mime-type", em);
}
}
assert contentMimeType != null;
// If no character encoding is specified, guess at Latin-1
String charSet = contentMimeType.getParameter("charset");
if (charSet == null) {
charSet = "ISO8859-1";
}
assert charSet != null;
// Get the content, performing appropriate character encoding
input = connection.getInputStream();
reader = new InputStreamReader(input, charSet);
// Add a filter if the content type is text/html, to strip out
// HTML keywords that will clutter the index
try {
if (contentMimeType.match(new MimeType("text", "html"))) {
reader = HtmlToTextConverter.convert(reader);
}
} catch (MimeTypeParseException em) {
throw new ResolverException("Failed to create mime-type", em);
}
if (logger.isDebugEnabled()) {
logger.debug("Inserting " + subject + " " + predicate + " " + resource);
}
if (!stringIndex.add(subject, predicate, resource, reader)) {
logger.warn(
"Unable to add {"
+ subject
+ ", "
+ predicate
+ ", "
+ resource
+ "} to full text string index");
}
} catch (MalformedURLException e) {
logger.info(resource + " is not a URL; ignoring Lucene insert");
} catch (IOException e) {
throw new ResolverException("Can't obtain content of " + resource, e);
} catch (org.mulgara.util.conversion.html.ParseException e) {
throw new ResolverException("Couldn't parse content of " + resource, e);
} finally {
try {
if (reader != null) reader.close();
else if (input != null) input.close();
} catch (IOException e) {
logger.warn("Ignoring error closing resource content", e);
}
}
} else { // (!occurs)
if (logger.isDebugEnabled()) {
logger.debug("Deleting " + subject + " " + predicate + " " + resource);
}
if (!stringIndex.remove(subject, predicate, resource)) {
logger.warn(
"Unable to remove {"
+ subject
+ ", "
+ predicate
+ ", "
+ resource
+ "} from full text string index");
}
}
} catch (FullTextStringIndexException e) {
throw new ResolverException("Unable to modify full text index\n" + new StackTrace(e));
}
} else if (objectNode instanceof Literal) {
Literal objectLiteral = (Literal) objectNode;
String literal = objectLiteral.getLexicalForm();
// Insert the statement into the text index
try {
if (occurs) {
if (logger.isDebugEnabled()) {
logger.debug("Inserting " + subject + " " + predicate + " " + literal);
}
if (!stringIndex.add(subject, predicate, literal)) {
logger.warn(
"Unable to add {"
+ subject
+ ", "
+ predicate
+ ", "
+ literal
+ "} to full text string index");
}
} else {
if (logger.isDebugEnabled()) {
logger.debug("Deleting " + subject + " " + predicate + " " + literal);
}
if (!stringIndex.remove(subject, predicate, literal)) {
logger.warn(
"Unable to remove {"
+ subject
+ ", "
+ predicate
+ ", "
+ literal
+ "} from full text string index");
}
}
} catch (FullTextStringIndexException e) {
throw new ResolverException(
"Unable to "
+ (occurs ? "add" : "delete")
+ "'"
+ literal
+ "' to full text string index\n"
+ new StackTrace(e));
}
} else {
if (logger.isInfoEnabled()) {
logger.info(objectNode + " is blank node; ignoring Lucene insert.");
}
}
}
} catch (TuplesException et) {
throw new ResolverException("Error fetching statements", et);
} catch (GlobalizeException eg) {
throw new ResolverException("Error localizing statements", eg);
} catch (IOException ioe) {
throw new ResolverException("Failed to open string index", ioe);
} catch (FullTextStringIndexException ef) {
throw new ResolverException("Error in string index\n" + new StackTrace(ef));
}
}
/** {@inheritDoc} */
protected void addURI(URIReference uri) throws IOException {
s.append(i(4)).append("<uri>").append(uri.getURI().toString()).append("</uri>");
}