/**
* @param g Where to assemble the description.
* @param tripleStore The KB instance to be described.
* @param serviceURI The SPARQL service end point.
* @param aDefaultDataset The data set identifier that will be used on the description (the
* bigdata namespace of the dataset is obtained from the <i>tripleStore</i>).
*/
public VoID(
final Graph g,
final AbstractTripleStore tripleStore,
final String[] serviceURI,
final Resource aDataset) {
if (g == null) throw new IllegalArgumentException();
if (tripleStore == null) throw new IllegalArgumentException();
if (serviceURI == null) throw new IllegalArgumentException();
if (serviceURI.length == 0) throw new IllegalArgumentException();
for (String s : serviceURI) if (s == null) throw new IllegalArgumentException();
if (aDataset == null) throw new IllegalArgumentException();
this.g = g;
this.tripleStore = tripleStore;
this.serviceURI = serviceURI;
this.f = g.getValueFactory();
this.aDataset = aDataset;
this.aDefaultGraph = f.createBNode("defaultGraph");
}
/**
* Implementation using the json.org API.
*
* @param json The RDF/JSON string to be parsed and converted into a Sesame Graph.
* @return A Sesame Graph if successful, otherwise null.
*/
public static Graph rdfJsonToGraph(String json) {
Graph result = new GraphImpl();
ValueFactory vf = result.getValueFactory();
try {
JSONObject input = new JSONObject(json);
Iterator<String> subjects = input.keys();
while (subjects.hasNext()) {
String subjStr = subjects.next();
Resource subject = null;
subject =
subjStr.startsWith("_:") ? vf.createBNode(subjStr.substring(2)) : vf.createURI(subjStr);
JSONObject pObj = input.getJSONObject(subjStr);
Iterator<String> predicates = pObj.keys();
while (predicates.hasNext()) {
String predStr = predicates.next();
URI predicate = vf.createURI(predStr);
JSONArray predArr = pObj.getJSONArray(predStr);
for (int i = 0; i < predArr.length(); i++) {
Value object = null;
JSONObject obj = predArr.getJSONObject(i);
if (!obj.has("value")) {
continue;
}
String value = obj.getString("value");
if (!obj.has("type")) {
continue;
}
String type = obj.getString("type");
String lang = null;
if (obj.has("lang")) {
lang = obj.getString("lang");
}
String datatype = null;
if (obj.has("datatype")) {
datatype = obj.getString("datatype");
}
if ("literal".equals(type)) {
if (lang != null) {
object = vf.createLiteral(value, lang);
} else if (datatype != null) {
object = vf.createLiteral(value, vf.createURI(datatype));
} else {
object = vf.createLiteral(value);
}
} else if ("bnode".equals(type)) {
object = vf.createBNode(value.substring(2));
} else if ("uri".equals(type)) {
object = vf.createURI(value);
}
if (obj.has("graphs")) {
JSONArray a = obj.getJSONArray("graphs");
// System.out.println("a.length() = " + a.length());
for (int j = 0; j < a.length(); j++) {
// Note: any nulls here will result in statements in the default context.
String s = a.getString(j);
Resource context = s.equals("null") ? null : vf.createURI(s);
// System.out.println("context = " + context);
result.add(subject, predicate, object, context);
}
} else {
result.add(subject, predicate, object);
}
}
}
}
} catch (JSONException e) {
log.error(e.getMessage(), e);
return null;
}
return result;
}