prototype: first test using jena

Author: giancarlopro

bin/.keep

@@ -1,5 +1,7 @@
 package app;
 
+import com.semanticcrawler.impl.SemanticCrawlerImpl;
+
 import org.apache.jena.datatypes.xsd.XSDDatatype;
 import org.apache.jena.rdf.model.Model;
 import org.apache.jena.rdf.model.ModelFactory;
@@ -11,10 +13,9 @@ public class App {
     public static void main(String[] args) throws Exception {
         Model model = ModelFactory.createDefaultModel();
 
-        Resource subject = model.createResource(namespace + "message");
-        Property property = model.createProperty(namespace + "says");
-        subject.addProperty(property, "Hello World!", XSDDatatype.XSDstring);
+        SemanticCrawlerImpl crawler = new SemanticCrawlerImpl();
+        crawler.search(model, "http://dbpedia.org/resource/Zico");
 
-        model.write(System.out);
+        // model.write(System.out);
     }
 }

src/app/App.java

@@ -0,0 +1,64 @@
+package com.semanticcrawler.impl;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.semanticcrawler.crawler.SemanticCrawler;
+
+import org.apache.jena.rdf.model.Model;
+import org.apache.jena.rdf.model.ModelFactory;
+import org.apache.jena.rdf.model.Property;
+import org.apache.jena.rdf.model.RDFNode;
+import org.apache.jena.rdf.model.Resource;
+import org.apache.jena.rdf.model.Statement;
+import org.apache.jena.rdf.model.StmtIterator;
+import org.apache.jena.vocabulary.OWL;
+
+/**
+ * SemanticCrawlerImpl
+ */
+public class SemanticCrawlerImpl implements SemanticCrawler {
+    private List<String> visitedURIs;
+
+    public SemanticCrawlerImpl() {
+        this.visitedURIs = new ArrayList<>();
+    }
+
+    private boolean visited(String URI) {
+        return visitedURIs.contains(URI);
+    }
+
+    private boolean isOwlSameAsProperty(Property property) {
+        return property.getURI().equals(OWL.sameAs.getURI());
+    }
+
+    @Override
+    public void search(Model graph, String resourceURI) {
+        Model model = ModelFactory.createDefaultModel();
+        model.read(resourceURI);
+
+        Resource resource = model.getResource(resourceURI);
+
+        StmtIterator statements = model.listStatements(resource, (Property)null, (RDFNode)null);
+        while (statements.hasNext()) {
+            Statement statement = statements.next();
+            Property property = statement.getPredicate();
+            RDFNode value = statement.getObject();
+            
+            if (isOwlSameAsProperty(property)) {
+                String uri = value.asNode().getURI();
+                try {
+                    if (!visited(uri)) {
+                        System.out.println(uri);
+                        this.visitedURIs.add(uri);
+                        search(graph, uri);
+                    }
+                } catch (Exception e) {
+                    e.equals(null);
+                }
+            } else {
+                graph.add(resource, statement.getPredicate(), statement.getObject());
+            }
+        }
+    }
+}