package com.bigdata.gom;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.eclipse.jetty.client.HttpClient;
import org.openrdf.model.Resource;
import org.openrdf.model.Statement;
import com.bigdata.BigdataStatics;
import com.bigdata.gom.gpo.IGPO;
import com.bigdata.gom.om.IObjectManager;
import com.bigdata.gom.om.NanoSparqlObjectManager;
import com.bigdata.rdf.sail.webapp.client.HttpClientConfigurator;
import com.bigdata.rdf.sail.webapp.client.RemoteRepositoryManager;
import com.bigdata.util.httpd.Config;
import cutthecrap.utils.striterators.ICloseableIterator;
/**
* Simple graph program constructs a local graph using a SPARQL query that
* extracts edges of interest from the SPARQL server.
* <p>
* To get started, start the NanoSparqlServer. Then LOAD the data set into the
* server using SPARQL UPDATE (you will have to use the path the file on your
* local machine).
*
* <pre>
* LOAD <file:///Users/bryan/Documents/workspace/BIGDATA_RELEASE_1_2_0/bigdata-gom/src/samples/com/bigdata/gom/samples/example2.trig>
* </pre>
*
* You can then run this example, and it will construct the graph. You can load
* a different data set if you want to test this out on your own data.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class Example1 implements Callable<Void> {
private final IObjectManager om;
public Example1(final IObjectManager om) {
this.om = om;
}
@Override
public Void call() throws Exception {
final ICloseableIterator<Statement> itr = om
.evaluateGraph(
"PREFIX foaf: <http://xmlns.com/foaf/0.1/> \n" + //
"CONSTRUCT { \n"+//
" ?u a foaf:Person . \n" + //
" ?u foaf:knows ?v . \n"+
" ?u rdfs:label ?name . \n"+
"} \n"+//
"WHERE {\n"+//
" ?u a foaf:Person . \n" + //
" ?u foaf:knows ?v . \n"+
" OPTIONAL { ?u rdfs:label ?name } . \n"+
"} LIMIT 100"//
);
final Map<Resource, IGPO> vertices = om.initGPOs(itr);
System.out.println("Found " + vertices.size() + " instances.");
for(IGPO gpo : vertices.values()) {
System.out.println(gpo.pp());
}
return null;
}
static public void main(final String[] args) throws Exception {
/**
* The top-level SPARQL end point for a NanoSparqlServer instance.
*/
final String serviceURL = "http://localhost:" + Config.BLAZEGRAPH_HTTP_PORT + "/"
+ BigdataStatics.getContextPath();
/**
* The namespace of the KB instance that you want to connect to on that
* server. The default namespace is "kb".
*/
final String namespace = "kb";
ExecutorService executor = null;
RemoteRepositoryManager repo = null;
HttpClient client = null;
try {
executor = Executors.newCachedThreadPool();
client = HttpClientConfigurator.getInstance().newInstance();
repo = new RemoteRepositoryManager(
serviceURL, client, executor);
final IObjectManager om = new NanoSparqlObjectManager(repo.getRepositoryForDefaultNamespace(),
namespace);
new Example1(om).call();
} finally {
if (repo != null) {
repo.close();
}
if (client != null) {
client.stop();
}
if (executor != null) {
executor.shutdownNow();
}
}
}
}