#25 Issue: Wikidata URI Grounding

.vscode/settings.json

@@ -1,3 +1,4 @@
 {
-    "java.configuration.updateBuildConfiguration": "interactive"
+    "java.configuration.updateBuildConfiguration": "interactive",
+    "java.compile.nullAnalysis.mode": "automatic"
 }

src/main/java/chatbot/Application.java

@@ -2,6 +2,7 @@
 
 import chatbot.cache.WolframRepository;
 import chatbot.lib.api.SPARQL;
+import chatbot.lib.api.WikidataSPARQL;
 import chatbot.rivescript.RiveScriptBot;
 import codeanticode.eliza.ElizaMain;
 import com.cloudant.client.api.CloudantClient;
@@ -113,6 +114,7 @@ public static class Helper {
         private WolframRepository wolframRepository;
         private String tmdbApiKey;
         private SPARQL sparql;
+        private WikidataSPARQL wikidataSparql;
         private JLanguageTool languageTool;
 
         @Autowired
@@ -154,6 +156,8 @@ public Helper(final CloudantClient cloudantClient,
                     ? new SPARQL(explorerDB)
                     : SPARQL.disabled();
 
+            wikidataSparql = new WikidataSPARQL();
+
             languageTool = new JLanguageTool(new AmericanEnglish());
             for (Rule rule : languageTool.getAllActiveRules()) {
                 if (rule instanceof SpellingCheckRule) {
@@ -199,6 +203,10 @@ public SPARQL getSparql() {
             return sparql;
         }
 
+        public WikidataSPARQL getWikidataSparql() {
+            return wikidataSparql;
+        }
+
         public JLanguageTool getLanguageTool() {
             return languageTool;
         }

src/main/java/chatbot/lib/Utility.java

@@ -104,4 +104,25 @@ public static String convertDBpediaToWikipediaURL(String url) {
         String[] urlsParts = url.split("/");
         return "https://en.wikipedia.org/wiki/" + urlsParts[urlsParts.length - 1];
     }
+
+    public static boolean isWikidataURI(String uri) {
+        return uri != null && uri.startsWith("http://www.wikidata.org/entity/");
+    }
+
+    public static boolean isDBpediaURI(String uri) {
+        return uri != null && uri.startsWith("http://dbpedia.org/resource/");
+    }
+
+    /**
+     * Extracts the Wikidata entity ID (e.g. "Q42") from a Wikidata URI.
+     */
+    public static String extractWikidataEntityId(String uri) {
+        if (uri == null) return null;
+        String[] parts = uri.split("/");
+        String id = parts[parts.length - 1];
+        if (id.matches("^[QPL]\\d+$")) {
+            return id;
+        }
+        return null;
+    }
 }

src/main/java/chatbot/lib/api/WikidataSPARQL.java

@@ -0,0 +1,152 @@
+package chatbot.lib.api;
+
+import chatbot.lib.Constants;
+import chatbot.lib.Utility;
+import chatbot.lib.request.TemplateType;
+import chatbot.lib.response.ResponseData;
+import chatbot.lib.response.ResponseType;
+import org.apache.jena.query.*;
+import org.apache.jena.sparql.engine.http.QueryEngineHTTP;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.*;
+
+/**
+ * Service for querying the Wikidata SPARQL endpoint to retrieve entity
+ * information.
+ * Mirrors the interface of the DBpedia SPARQL class but targets Wikidata.
+ */
+public class WikidataSPARQL {
+    private static final Logger logger = LoggerFactory.getLogger(WikidataSPARQL.class);
+
+    private static final String ENDPOINT = "https://query.wikidata.org/sparql";
+    private static final String PREFIXES = "PREFIX wd: <http://www.wikidata.org/entity/>\n" +
+            "PREFIX wdt: <http://www.wikidata.org/prop/direct/>\n" +
+            "PREFIX wikibase: <http://wikiba.se/ontology#>\n" +
+            "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n" +
+            "PREFIX schema: <http://schema.org/>\n";
+
+    public WikidataSPARQL() {
+    }
+
+    public String buildQuery(String query) {
+        return PREFIXES + query;
+    }
+
+    /**
+     * Retrieves entity information from Wikidata for the given URI.
+     * Returns a ResponseData card with label, description, image, Wikipedia link,
+     * and Wikidata link.
+     */
+    public ResponseData getEntityInformation(String uri) {
+        String entityId = Utility.extractWikidataEntityId(uri);
+        if (entityId == null) {
+            return null;
+        }
+
+        String query = buildQuery(
+                "SELECT ?label ?description ?image ?articleEN WHERE {\n" +
+                        "  wd:" + entityId + " rdfs:label ?label . FILTER(lang(?label) = 'en') .\n" +
+                        "  OPTIONAL { wd:" + entityId
+                        + " schema:description ?description . FILTER(lang(?description) = 'en') }\n" +
+                        "  OPTIONAL { wd:" + entityId + " wdt:P18 ?image }\n" +
+                        "  OPTIONAL {\n" +
+                        "    ?articleEN schema:about wd:" + entityId + " ;\n" +
+                        "              schema:isPartOf <https://en.wikipedia.org/> .\n" +
+                        "  }\n" +
+                        "} LIMIT 1");
+
+        QueryExecution queryExecution = null;
+        ResponseData responseData = null;
+
+        try {
+            queryExecution = executeQuery(query);
+            Iterator<QuerySolution> results = queryExecution.execSelect();
+            if (results.hasNext()) {
+                QuerySolution result = results.next();
+                responseData = new ResponseData();
+
+                // Label
+                String label = result.get("label").asLiteral().getString();
+                responseData.setTitle(label);
+
+                // Description
+                if (result.get("description") != null) {
+                    responseData.setText(result.get("description").asLiteral().getString());
+                }
+
+                // Thumbnail / Image
+                if (result.get("image") != null) {
+                    responseData.setImage(result.get("image").toString());
+                }
+
+                // Wikipedia link
+                if (result.get("articleEN") != null) {
+                    responseData.addButton(new ResponseData.Button("View in Wikipedia", ResponseType.BUTTON_LINK,
+                            result.get("articleEN").toString()));
+                }
+
+                // Wikidata link
+                responseData.addButton(new ResponseData.Button("View in Wikidata", ResponseType.BUTTON_LINK, uri));
+
+                // Learn More button (reuses the existing template mechanism)
+                responseData.addButton(new ResponseData.Button("Learn More", ResponseType.BUTTON_PARAM,
+                        TemplateType.LEARN_MORE + Utility.STRING_SEPARATOR + uri + Utility.STRING_SEPARATOR + label));
+            }
+        } catch (Exception e) {
+            logger.error("Error querying Wikidata for entity: " + uri, e);
+        } finally {
+            if (queryExecution != null) {
+                queryExecution.close();
+            }
+        }
+        return responseData;
+    }
+
+    /**
+     * Retrieves the English label for a Wikidata entity.
+     */
+    public String getLabel(String uri) {
+        String entityId = Utility.extractWikidataEntityId(uri);
+        if (entityId == null)
+            return null;
+
+        String query = buildQuery(
+                "SELECT ?label WHERE {\n" +
+                        "  wd:" + entityId + " rdfs:label ?label . FILTER(lang(?label) = 'en') .\n" +
+                        "} LIMIT 1");
+
+        QueryExecution queryExecution = executeQuery(query);
+        String label = null;
+
+        try {
+            Iterator<QuerySolution> results = queryExecution.execSelect();
+            if (results.hasNext()) {
+                label = results.next().get("label").asLiteral().getString();
+            }
+        }
+        catch (Exception e) {
+            logger.error("Error querying Wikidata for label: " + uri, e);
+        }
+        finally {
+            if (queryExecution != null) {
+                queryExecution.close();
+            }
+        }
+        return label;
+    }
+
+    /**
+     * Executes a SPARQL query against the Wikidata endpoint.
+     */
+    public QueryExecution executeQuery(String queryString) {
+        logger.info("Wikidata SPARQL Query is:\n" + queryString);
+        Query query = QueryFactory.create(queryString);
+        QueryEngineHTTP queryEngine = (QueryEngineHTTP) QueryExecutionFactory.sparqlService(ENDPOINT, query);
+        queryEngine.addParam("timeout", String.valueOf(Constants.API_TIMEOUT));
+        // Wikidata requires a User-Agent header
+        queryEngine.addParam("format", "json");
+        return queryEngine;
+    }
+}

src/main/java/chatbot/lib/api/qa/QANARY.java

@@ -22,9 +22,6 @@
 import java.util.List;
 import java.util.Map;
 
-/**
- * Created by ramgathreya on 7/1/17.
- */
 public class QANARY {
     private static final Logger logger = LoggerFactory.getLogger(QANARY.class);
     private static final String URL = "http://qanswer-core1.univ-st-etienne.fr/api/gerbil";
@@ -36,50 +33,55 @@ public QANARY() {
         this.client = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
     }
 
-    private String makeRequest(String question) {
+    private String makeRequest(String question, String knowledgeBase) {
         try {
             HttpPost httpPost = new HttpPost(URL);
             List<NameValuePair> params = new ArrayList<>();
             params.add(new BasicNameValuePair("query", question));
-//            params.add(new BasicNameValuePair("lang", "it"));
-            params.add(new BasicNameValuePair("kb", "dbpedia"));
+            params.add(new BasicNameValuePair("kb", knowledgeBase));
 
             UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params, Consts.UTF_8);
             httpPost.setEntity(entity);
 
             HttpResponse response = client.execute(httpPost);
 
             // Error Scenario
-            if(response.getStatusLine().getStatusCode() >= 400) {
-                logger.error("QANARY Server could not answer due to: " + response.getStatusLine());
+            if (response.getStatusLine().getStatusCode() >= 400) {
+                logger.error("QANARY Server could not answer for kb=" + knowledgeBase + " due to: "
+                        + response.getStatusLine());
                 return null;
             }
 
             return EntityUtils.toString(response.getEntity());
-        }
-        catch(Exception e) {
-            logger.error(e.getMessage());
+        } catch (Exception e) {
+            logger.error("QANARY request failed for kb=" + knowledgeBase + ": " + e.getMessage());
         }
         return null;
     }
 
-    // Calls QANARY Service then returns resulting data as a list of Data Objects
-    public QAService.Data search(String question) throws Exception {
+    private QAService.Data parseResponse(String response) throws Exception {
         QAService.Data data = new QAService.Data();
-        String response = makeRequest(question);
-        if(response != null) {
+        if (response != null) {
             ObjectMapper mapper = new ObjectMapper();
             JsonNode rootNode = mapper.readTree(response);
-            JsonNode answers = mapper.readTree(rootNode.findValue("questions").get(0).get("question").get("answers").getTextValue());
+            JsonNode questions = rootNode.findValue("questions");
+            if (questions == null || !questions.isArray() || questions.size() == 0) {
+                return data;
+            }
+            JsonNode questionNode = questions.get(0).get("question");
+            if (questionNode == null || questionNode.get("answers") == null) {
+                return data;
+            }
+            JsonNode answers = mapper.readTree(questionNode.get("answers").getTextValue());
 
             if (answers != null) {
                 JsonNode bindings = answers.get("results").get("bindings");
-                for(JsonNode binding : bindings) {
+                for (JsonNode binding : bindings) {
                     Iterator<Map.Entry<String, JsonNode>> nodes = binding.getFields();
                     while (nodes.hasNext()) {
                         Map.Entry<String, JsonNode> entry = nodes.next();
                         JsonNode value = entry.getValue();
-                        switch(value.get("type").getTextValue()) {
+                        switch (value.get("type").getTextValue()) {
                             case "uri":
                                 data.addURI(value.get("value").getTextValue());
                                 break;
@@ -94,4 +96,27 @@ public QAService.Data search(String question) throws Exception {
         return data;
     }
 
+    public QAService.Data search(String question) throws Exception {
+
+        QAService.Data data = new QAService.Data();
+
+        // Query DBpedia KB
+        try {
+            QAService.Data dbpediaData = parseResponse(makeRequest(question, "dbpedia"));
+            data.addData(dbpediaData, false);
+        } catch (Exception e) {
+            logger.error("DBpedia QANARY query failed: " + e.getMessage());
+        }
+
+        // Query Wikidata KB
+        try {
+            QAService.Data wikidataData = parseResponse(makeRequest(question, "wikidata"));
+            data.addData(wikidataData, false);
+        } catch (Exception e) {
+            logger.error("Wikidata QANARY query failed, continuing with DBpedia results only: " + e.getMessage());
+        }
+
+        return data;
+    }
+
 }

src/main/java/chatbot/lib/handlers/NLHandler.java

@@ -2,6 +2,7 @@
 
 import chatbot.Application;
 import chatbot.lib.Utility;
+import chatbot.lib.api.WikidataSPARQL;
 import chatbot.lib.api.StatusCheckService;
 import chatbot.lib.api.qa.QAService;
 import chatbot.lib.api.SPARQL;
@@ -111,21 +112,33 @@ else if(uris.size() > 0) {
                         break;
                     }
 
-                    count = helper.getSparql().isDisambiguationPage(uri);
-                    processedResponse.setResponseType(SPARQL.ProcessedResponse.RESPONSE_CAROUSEL);
-
-                    // Not a disambiguation page
-                    if(count == 0) {
-                        ResponseData responseData = helper.getSparql().getEntityInformation(uri);
+                    // Route Wikidata URIs to WikidataSPARQL
+                    if(Utility.isWikidataURI(uri)) {
+                        processedResponse.setResponseType(SPARQL.ProcessedResponse.RESPONSE_CAROUSEL);
+                        WikidataSPARQL wikidataSparql = helper.getWikidataSparql();
+                        ResponseData responseData = wikidataSparql.getEntityInformation(uri);
                         if (responseData != null) {
                             processedResponse.addResponseData(responseData);
                         }
                     }
-                    // Disambiguation page
+                    // Route DBpedia URIs to DBpedia SPARQL (existing behavior)
                     else {
-                        processedResponse.getResponseInfo().setUri(uri).setCount(count).setQueryResultType(SPARQL.ResponseInfo.DISAMBIGUATION_PAGE).setOffset(0).setLimit(ResponseData.MAX_DATA_SIZE);
-                        processedResponse.setResponseData(helper.getSparql().getDisambiguatedEntities(uri, 0, ResponseData.MAX_DATA_SIZE));
-                        return processedResponse;
+                        count = helper.getSparql().isDisambiguationPage(uri);
+                        processedResponse.setResponseType(SPARQL.ProcessedResponse.RESPONSE_CAROUSEL);
+
+                        // Not a disambiguation page
+                        if(count == 0) {
+                            ResponseData responseData = helper.getSparql().getEntityInformation(uri);
+                            if (responseData != null) {
+                                processedResponse.addResponseData(responseData);
+                            }
+                        }
+                        // Disambiguation page
+                        else {
+                            processedResponse.getResponseInfo().setUri(uri).setCount(count).setQueryResultType(SPARQL.ResponseInfo.DISAMBIGUATION_PAGE).setOffset(0).setLimit(ResponseData.MAX_DATA_SIZE);
+                            processedResponse.setResponseData(helper.getSparql().getDisambiguatedEntities(uri, 0, ResponseData.MAX_DATA_SIZE));
+                            return processedResponse;
+                        }
                     }
                 }
             }