Merge conflict

Author: Miel Vander Sande

src/org/linkeddatafragments/config/ConfigReader.java

@@ -17,6 +17,7 @@
 public class ConfigReader {
     private final Map<String, JsonObject> dataSources = new HashMap<>();
     private final Map<String, String> prefixes = new HashMap<>();
+    private final String baseURL;
 
     /**
      * Creates a new configuration reader.
@@ -25,6 +26,8 @@ public class ConfigReader {
      */
     public ConfigReader(Reader configReader) {
         JsonObject root = new JsonParser().parse(configReader).getAsJsonObject();
+        this.baseURL = root.has("baseURL") ? root.getAsJsonPrimitive("baseURL").getAsString() : null;
+        
         for (Entry<String, JsonElement> entry : root.getAsJsonObject("datasources").entrySet()) {
             JsonObject dataSource = entry.getValue().getAsJsonObject();
             this.dataSources.put(entry.getKey(), dataSource);
@@ -51,4 +54,8 @@ public Map<String, JsonObject> getDataSources() {
     public Map<String, String> getPrefixes() {
         return prefixes;
     }
+
+    public String getBaseURL() {
+        return baseURL;
+    }
 }

src/org/linkeddatafragments/datasource/IndexDataSource.java

@@ -0,0 +1,64 @@
+package org.linkeddatafragments.datasource;
+
+import com.hp.hpl.jena.rdf.model.Model;
+import com.hp.hpl.jena.rdf.model.ModelFactory;
+import com.hp.hpl.jena.rdf.model.Property;
+import com.hp.hpl.jena.rdf.model.RDFNode;
+import com.hp.hpl.jena.rdf.model.Resource;
+import com.hp.hpl.jena.rdf.model.StmtIterator;
+import com.hp.hpl.jena.rdf.model.impl.PropertyImpl;
+import com.hp.hpl.jena.rdf.model.impl.ResourceImpl;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * An Index data source provides an overview of all available datasets.
+ *
+ * @author Miel Vander Sande
+ */
+public class IndexDataSource extends DataSource {
+
+    final String RDF = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
+    final String RDFS = "http://www.w3.org/2000/01/rdf-schema#";
+    final String DC = "http://purl.org/dc/terms/";
+    final String VOID = "http://rdfs.org/ns/void#";
+
+    private final Model model;
+
+    public IndexDataSource(String baseUrl, HashMap<String, IDataSource> datasources) {
+        super("Index", "List of all datasources");
+
+        this.model = ModelFactory.createDefaultModel();
+
+        for (Map.Entry<String, IDataSource> entry : datasources.entrySet()) {
+            String datasourceName = entry.getKey();
+            IDataSource datasource = entry.getValue();
+
+            Resource datasourceUrl = new ResourceImpl(baseUrl + "/" + datasourceName);
+
+            model.add(datasourceUrl, new PropertyImpl(RDF + "type"), VOID + "Dataset");
+            model.add(datasourceUrl, new PropertyImpl(RDFS + "label"), datasource.getTitle());
+            model.add(datasourceUrl, new PropertyImpl(DC + "title"), datasource.getTitle());
+            model.add(datasourceUrl, new PropertyImpl(DC + "description"), datasource.getDescription());
+        }
+    }
+
+    @Override
+    public TriplePatternFragment getFragment(Resource subject, Property predicate, RDFNode object, long offset, long limit) {
+        StmtIterator listStatements = this.model.listStatements(subject, predicate, object);
+        Model result = ModelFactory.createDefaultModel();
+        
+        long index = 0;
+        while (listStatements.hasNext() && index < offset) {
+            listStatements.next();
+            index++;
+        }
+
+        while (listStatements.hasNext() && index < (offset + limit)) {
+            result.add(listStatements.next());
+        }
+
+        return new TriplePatternFragmentBase(result, result.size());
+    }
+
+}