diff --git a/pom.xml b/pom.xml
index 61412fd9f2987954410ca0e90dea3f2be3015a8e..e5075ff54a36a4fa46cbd3c36878cc0d0039c0af 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,58 +18,84 @@
<maven.compiler.target>17</maven.compiler.target>
</properties>
- <dependencies>
- <dependency>
- <groupId>junit</groupId>
- <artifactId>junit</artifactId>
- <version>4.11</version>
- <scope>test</scope>
- </dependency>
- </dependencies>
+ <dependencies>
+ <dependency>
+ <groupId>junit</groupId>
+ <artifactId>junit</artifactId>
+ <version>4.11</version>
+ <scope>test</scope>
+ </dependency>
+ <dependency>
+ <groupId>org.apache.jena</groupId>
+ <artifactId>apache-jena-libs</artifactId>
+ <type>pom</type>
+ <version>4.2.0</version>
+ </dependency>
+ <dependency>
+ <groupId>org.apache.logging.log4j</groupId>
+ <artifactId>log4j-api</artifactId>
+ <version>2.14.1</version>
+ </dependency>
+ <dependency>
+ <groupId>org.apache.logging.log4j</groupId>
+ <artifactId>log4j-core</artifactId>
+ <version>2.14.1</version>
+ </dependency>
+ </dependencies>
- <build>
- <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
- <plugins>
- <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
- <plugin>
- <artifactId>maven-clean-plugin</artifactId>
- <version>3.1.0</version>
- </plugin>
- <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
- <plugin>
- <artifactId>maven-resources-plugin</artifactId>
- <version>3.0.2</version>
- </plugin>
- <plugin>
- <artifactId>maven-compiler-plugin</artifactId>
- <version>3.8.0</version>
- </plugin>
- <plugin>
- <artifactId>maven-surefire-plugin</artifactId>
- <version>2.22.1</version>
- </plugin>
- <plugin>
- <artifactId>maven-jar-plugin</artifactId>
- <version>3.0.2</version>
- </plugin>
- <plugin>
- <artifactId>maven-install-plugin</artifactId>
- <version>2.5.2</version>
- </plugin>
- <plugin>
- <artifactId>maven-deploy-plugin</artifactId>
- <version>2.8.2</version>
- </plugin>
- <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
- <plugin>
- <artifactId>maven-site-plugin</artifactId>
- <version>3.7.1</version>
- </plugin>
- <plugin>
- <artifactId>maven-project-info-reports-plugin</artifactId>
- <version>3.0.0</version>
- </plugin>
- </plugins>
- </pluginManagement>
- </build>
+ <build>
+ <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
+ <plugins>
+ <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
+ <plugin>
+ <artifactId>maven-clean-plugin</artifactId>
+ <version>3.1.0</version>
+ </plugin>
+ <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
+ <plugin>
+ <artifactId>maven-resources-plugin</artifactId>
+ <version>3.0.2</version>
+ </plugin>
+ <plugin>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <version>3.8.0</version>
+ </plugin>
+ <plugin>
+ <artifactId>maven-surefire-plugin</artifactId>
+ <version>2.22.1</version>
+ </plugin>
+ <plugin>
+ <artifactId>maven-jar-plugin</artifactId>
+ <version>3.0.2</version>
+ </plugin>
+ <plugin>
+ <artifactId>maven-install-plugin</artifactId>
+ <version>2.5.2</version>
+ </plugin>
+ <plugin>
+ <artifactId>maven-deploy-plugin</artifactId>
+ <version>2.8.2</version>
+ </plugin>
+ <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
+ <plugin>
+ <artifactId>maven-site-plugin</artifactId>
+ <version>3.7.1</version>
+ </plugin>
+ <plugin>
+ <artifactId>maven-project-info-reports-plugin</artifactId>
+ <version>3.0.0</version>
+ </plugin>
+ </plugins>
+ </pluginManagement>
+ <plugins>
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <configuration>
+ <source>17</source>
+ <target>17</target>
+ </configuration>
+ </plugin>
+ </plugins>
+ </build>
</project>
diff --git a/src/main/java/com/kgshape/app/Query.java b/src/main/java/com/kgshape/app/Query.java
new file mode 100644
index 0000000000000000000000000000000000000000..2d6085526badc2235ce05f9ea48a1b59deed61f4
--- /dev/null
+++ b/src/main/java/com/kgshape/app/Query.java
@@ -0,0 +1,80 @@
+package com.kgshape.app;
+
+import org.apache.jena.query.*;
+import org.apache.jena.rdf.model.Model;
+import org.apache.jena.rdf.model.ModelFactory;
+import org.apache.jena.rdf.model.ModelFactoryBase;
+import org.apache.jena.riot.Lang;
+import org.apache.jena.riot.RDFDataMgr;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.config.Configurator;
+import org.apache.logging.log4j.core.config.DefaultConfiguration;
+
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.file.FileSystemNotFoundException;
+
+/**
+ * Queries a remote endpoint.
+ */
+public class Query {
+ public static void main(String[] args) throws IOException {
+ // https://stackoverflow.com/questions/41442024/basicconfigurator-replacement-in-log4j2
+ Configurator.initialize(new DefaultConfiguration());
+ Configurator.setRootLevel(Level.INFO);
+
+ // Get 20 different languages
+ String select_query = """
+ PREFIX o: <http://dbpedia.org/ontology/>
+ select distinct ?subj where {?subj a o:Language} LIMIT 20
+ """;
+ // Get 100 different actors
+ String construct_query = """
+ PREFIX o: <http://dbpedia.org/ontology/>
+ CONSTRUCT {?person ?pred ?obj}
+ WHERE {
+ ?person ?pred ?obj
+ {
+ SELECT DISTINCT(?person)
+ WHERE {
+ ?person a o:Actor
+ } LIMIT 100
+ }
+ }
+ """;
+ String construct_query2 = """
+ PREFIX o: <http://dbpedia.org/ontology/>
+ PREFIX dbr: <http://dbpedia.org/resource/>
+ CONSTRUCT {dbr:August_Westermark ?pred ?obj}
+ WHERE {
+ dbr:August_Westermark ?pred ?obj
+ }
+ """;
+ // You can also open this endpoint in the browser and test the above query
+ String endpoint = "https://dbpedia.org/sparql";
+
+ Model fetchedModel = fetchConstruct(endpoint, construct_query);
+ writeModel(fetchedModel, "rdf_file.ttl");
+ }
+
+ public static Model fetchConstruct(String endpoint, String query) {
+ // https://jena.apache.org/documentation/query/sparql-remote.html
+ // Also see: https://jena.apache.org/documentation/query/app_api.html
+ QueryExecution qexec = QueryExecutionFactory.sparqlService(endpoint, query);
+ Model resultModel = qexec.execConstruct();
+ qexec.close();
+ return resultModel;
+ }
+
+ public static void writeModel(Model model, String filename) throws FileSystemNotFoundException, IOException {
+// RDFDataMgr.write(System.out, model, Lang.TURTLE); // Write it to stdout
+
+ try (FileOutputStream fos = new FileOutputStream(filename)) {
+ // See: https://jena.apache.org/documentation/io/rdf-output.html#opt-turtle-trig
+ RDFDataMgr.write(fos, model, Lang.TURTLE);
+ } catch (Exception e) {
+ throw e;
+ }
+ }
+}