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Working Java model using Apache Jena
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‎java/README.md

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# CASE Conversion Examples (Java)
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This is an example script that uses the CASE graph to generate a GeoJSON output of locations. This highlights the value
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of utilizing the CASE Ontology to create a graph that can be used to query and generate data in a variety of formats,
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regardless of the source application's data model. This script is not production ready and does not properly handle
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errors. It is intended to be used as a starting point for a more robust solution.
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This is an example script that uses the CASE graph to generate a GeoJSON output of locations. This highlights the value of utilizing the CASE Ontology to create a graph that can be used to query and generate data in a variety of formats, regardless of the source application's data model. This script is not production ready and does not properly handle errors. It is intended to be used as a starting point for a more robust solution.
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## Usage
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@@ -22,3 +19,4 @@ java -jar ./target/case2geo-0.1.0.jar ../../data/locations.json ../../output/jav
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```
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## Dependencies
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This repository depends on several Java libraries, primarily Apache Jena. These dependencies are managed via Maven and can be viewed in the [`pom.xml`](./case2geo/pom.xml).

‎java/case2geo/pom.xml

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<properties>
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<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
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<maven.compiler.source>1.8</maven.compiler.source>
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<maven.compiler.target>1.8</maven.compiler.target>
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<maven.compiler.source>1.18</maven.compiler.source>
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<maven.compiler.target>1.18</maven.compiler.target>
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<exec.mainClass>org.caseontology.examples.CASE2Geo</exec.mainClass>
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</properties>
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<version>4.11</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.apache.jena</groupId>
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<artifactId>apache-jena-libs</artifactId>
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<version>3.9.0</version>
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<exclusions>
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<exclusion>
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<groupId>org.apache.jena</groupId>
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<artifactId>jena-tdb</artifactId>
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</exclusion>
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</exclusions>
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<type>pom</type>
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</dependency>
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<dependency>
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<groupId>ch.qos.logback</groupId>
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<artifactId>logback-classic</artifactId>
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<version>1.2.3</version>
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</dependency>
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<dependency>
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<groupId>com.github.jsonld-java</groupId>
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<artifactId>jsonld-java</artifactId>
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<version>0.13.4</version>
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</dependency>
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<dependency>
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<groupId>com.google.code.gson</groupId>
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<artifactId>gson</artifactId>
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<version>2.10.1</version>
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</dependency>
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</dependencies>
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<build>

‎java/case2geo/src/main/java/org/caseontology/examples/CASE2Geo.java

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package org.caseontology.examples;
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import java.io.File;
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import java.io.FileWriter;
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import java.io.IOException;
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/**
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* Hello world!
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*
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* The primary entrypoint for the CASE2GeoJSON application. This class is a simple command line application that
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* accepts two positional arguments: the path to an input file and the path to an output file. The input file is
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* expected to be an RDF graph containing location information. The output file will be a GeoJSON representation of
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* the input file.
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*/
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public class CASE2Geo
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{
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public static void main( String[] args )
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{
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// Ensure two arguments were provided and save them as the input and output paths
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public class CASE2Geo {
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public static void main(String[] args) {
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// Ensure two arguments were provided and save them as the input and output
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// paths
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if (args.length != 2) {
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System.out.println("Usage: java -jar CASE2GeoJSON.jar <inputPath> <outputPath>");
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System.exit(1);
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System.exit(1);
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}
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// Build an RDF graph from the input file
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// Build an RDF graph from the input file and convert it to GeoJSON
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GeoReader reader = new GeoReader(inputPath);
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String geoJSON = reader.run();
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// Convert the RDF graph to GeoJSON
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// TODO
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// Write the GeoJSON to the output file
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try {
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FileWriter fileWriter = new FileWriter(outputPath);
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fileWriter.write(geoJSON);
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fileWriter.close();
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} catch (IOException e) {
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System.out.println("Error writing output: " + e.getMessage());
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System.exit(1);
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}
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}
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}

‎java/case2geo/src/main/java/org/caseontology/examples/GeoReader.java

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package org.caseontology.examples;
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import org.apache.jena.query.QueryExecution;
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import org.apache.jena.query.QueryExecutionFactory;
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import org.apache.jena.query.QueryFactory;
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import org.apache.jena.query.QuerySolution;
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import org.apache.jena.rdf.model.Model;
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import java.io.FileInputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.lang.reflect.Field;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Iterator;
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import java.util.List;
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import org.apache.jena.graph.Node;
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import org.apache.jena.query.Query;
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import org.apache.jena.query.ResultSet;
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import org.apache.jena.rdf.model.ModelFactory;
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import org.apache.jena.riot.Lang;
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import org.apache.jena.riot.RDFDataMgr;
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import org.caseontology.examples.geojson.Feature;
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import org.caseontology.examples.geojson.GeoRecord;
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import org.caseontology.examples.geojson.Geometry;
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import org.caseontology.examples.geojson.Properties;
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import org.caseontology.examples.geojson.Root;
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import com.google.gson.Gson;
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import com.google.gson.GsonBuilder;
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public class GeoReader {
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private String InputPath;
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public GeoReader(String inputPath) {
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this.InputPath = inputPath;
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}
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/**
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* The primary entrypoint for the GeoReader class. This method will read the RDF graph from the input
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* file and convert it to GeoJSON string.
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*
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* @return the GeoJSON string generated from the input file
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*/
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public String run() {
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// Define the SPARQL query to execute to retrieve the location information from
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// the input file
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String queryString = """
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PREFIX uco-core: <https://ontology.unifiedcyberontology.org/uco/core/>
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PREFIX uco-location: <https://ontology.unifiedcyberontology.org/uco/location/>
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SELECT ?lLatitude ?lLongitude ?lAddressType ?lCountry ?lLocality ?lPostalCode ?lRegion ?lStreet
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WHERE
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{
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?nLocation a uco-location:Location .
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OPTIONAL
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{
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?nLocation uco-core:hasFacet ?nLatLongFacet .
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?nLatLongFacet a uco-location:LatLongCoordinatesFacet .
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OPTIONAL { ?nLatLongFacet uco-location:latitude ?lLatitude . }
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OPTIONAL { ?nLatLongFacet uco-location:longitude ?lLongitude . }
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}
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66+
OPTIONAL {
67+
?nLocation uco-core:hasFacet ?nSimpleAddressFacet .
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?nSimpleAddressFacet a uco-location:SimpleAddressFacet .
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OPTIONAL { ?nSimpleAddressFacet uco-location:addressType ?lAddressType . }
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OPTIONAL { ?nSimpleAddressFacet uco-location:country ?lCountry . }
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OPTIONAL { ?nSimpleAddressFacet uco-location:locality ?lLocality . }
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OPTIONAL { ?nSimpleAddressFacet uco-location:postalCode ?lPostalCode . }
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OPTIONAL { ?nSimpleAddressFacet uco-location:region ?lRegion . }
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OPTIONAL { ?nSimpleAddressFacet uco-location:street ?lStreet . }
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}
76+
}
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""";
78+
79+
try {
80+
// Load the input file into an RDF model
81+
Model model = getModel(this.InputPath);
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// Execute the SPARQL query on the RDF model
84+
ResultSet result = executeSparqlQuery(model, queryString);
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86+
// Convert the SPARQL query result to a list of GeoRecord objects
87+
List<GeoRecord> records = resultToObjects(result);
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89+
// Convert the list of GeoRecord objects to a GeoJSON string and return the string
90+
Gson gson = new GsonBuilder().setPrettyPrinting().create();
91+
Root geoJSON = recordsToGeoJSON(records);
92+
return gson.toJson(geoJSON);
93+
} catch (IOException e) {
94+
System.out.println("Error processing input: " + e.getMessage());
95+
e.printStackTrace();
96+
System.exit(1);
97+
}
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// This line will never be reached but the compiler complains if it is not explicitly returning a String value
100+
return "";
101+
}
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/**
104+
* Creates an RDF model from the provided input file.
105+
*
106+
* @param inputPath the path to the input file
107+
* @return Model the RDF graph built from the input file
108+
* @throws IOException if the input file does not exist or cannot be read
109+
*/
110+
private static Model getModel(String inputPath) throws IOException {
111+
Model model = ModelFactory.createDefaultModel();
112+
113+
InputStream inputStream = new FileInputStream(inputPath);
114+
RDFDataMgr.read(model, inputStream, Lang.JSONLD);
115+
116+
return model;
117+
}
118+
119+
/**
120+
* Executes a SPARQL query on the provided RDF model.
121+
*
122+
* @param model the RDF model to query
123+
* @param sparqlQuery the SPARQL query to execute
124+
*/
125+
private static ResultSet executeSparqlQuery(Model model, String sparqlQuery) {
126+
Query query = QueryFactory.create(sparqlQuery);
127+
QueryExecution queryExecution = QueryExecutionFactory.create(query, model);
128+
return queryExecution.execSelect();
129+
}
130+
131+
/**
132+
* Converts the result of a SPARQL query to a list of GeoRecord objects.
133+
*
134+
* @param resultSet the result of a SPARQL query to be converted
135+
* @return List<GeoRecord> a list of GeoRecord objects
136+
*/
137+
private static List<GeoRecord> resultToObjects(ResultSet resultSet) {
138+
// Initialize the list of geo Record objects
139+
List<GeoRecord> records = new ArrayList<GeoRecord>();
140+
141+
while (resultSet.hasNext()) {
142+
QuerySolution soln = resultSet.nextSolution();
143+
144+
// Initialize a new Record object
145+
GeoRecord record = new GeoRecord();
146+
// Get an iterator over the property names in the result set
147+
Iterator<String> names = soln.varNames();
148+
// For each property in the result set, strip the "l" prefix from the property
149+
// name and set the value of the corresponding property on the Record object
150+
while (names.hasNext()) {
151+
String property = names.next();
152+
String propertyName = property.substring(1);
153+
Node node = soln.get(property).asNode();
154+
if (node != null) {
155+
String value = node.getLiteralLexicalForm();
156+
try {
157+
Field field = record.getClass().getDeclaredField(propertyName);
158+
field.set(record, value);
159+
} catch (NoSuchFieldException | IllegalAccessException e) {
160+
System.out.println(
161+
"Error setting property " + propertyName + " on Record object: " + e.getMessage());
162+
}
163+
}
164+
}
165+
166+
// Add the record to the list of records to be returned
167+
records.add(record);
168+
}
169+
170+
return records;
171+
}
172+
173+
/**
174+
* Converts a list of GeoRecord objects to a GeoJSON object.
175+
*
176+
* @param records the list of GeoRecord objects to be converted
177+
* @return Root the GeoJSON object
178+
*/
179+
private static Root recordsToGeoJSON(List<GeoRecord> records) {
180+
Root root = new Root();
181+
root.type = "FeatureCollection";
182+
183+
for (GeoRecord record : records) {
184+
Feature feature = new Feature();
185+
feature.type = "Feature";
186+
feature.properties = new Properties();
187+
feature.properties.addressType = record.AddressType;
188+
feature.properties.country = record.Country;
189+
feature.properties.locality = record.Locality;
190+
feature.properties.postalCode = record.PostalCode;
191+
feature.properties.region = record.Region;
192+
feature.properties.street = record.Street;
193+
// The GeoJSON format expects coordinates in the format [longitude, latitude]
194+
// Only add the coordinates if the latitude and longitude are not null
195+
if (record.Latitude != null && record.Longitude != null) {
196+
feature.geometry = new Geometry();
197+
feature.geometry.coordinates = Arrays.asList(Double.parseDouble(record.Longitude),
198+
Double.parseDouble(record.Latitude));
199+
}
200+
201+
// Add the feature to the list of features in the GeoJSON object
202+
root.features.add(feature);
203+
}
204+
205+
return root;
206+
}
10207
}

‎java/case2geo/src/main/java/org/caseontology/examples/geojson/Feature.java

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package org.caseontology.examples.geojson;
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public class Feature {
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public String type;
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public Geometry geometry;
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public Properties properties;
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}

‎java/case2geo/src/main/java/org/caseontology/examples/geojson/GeoRecord.java

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package org.caseontology.examples.geojson;
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public class GeoRecord {
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public String Latitude;
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public String Longitude;
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public String AddressType;
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public String Country;
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public String Locality;
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public String PostalCode;
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public String Region;
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public String Street;
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}

‎java/case2geo/src/main/java/org/caseontology/examples/geojson/Geometry.java

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package org.caseontology.examples.geojson;
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import java.util.ArrayList;
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import java.util.List;
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public class Geometry {
7+
public String type;
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public List<Double> coordinates = new ArrayList<Double>();
9+
}

‎java/case2geo/src/main/java/org/caseontology/examples/geojson/Properties.java

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package org.caseontology.examples.geojson;
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public class Properties {
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public String addressType;
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public String street;
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public String locality;
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public String region;
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public String postalCode;
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public String country;
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}

‎java/case2geo/src/main/java/org/caseontology/examples/geojson/Root.java

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package org.caseontology.examples.geojson;
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import java.util.ArrayList;
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import java.util.List;
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public class Root {
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public String type;
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public List<Feature> features = new ArrayList<Feature>();
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}

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