ThingsManager.java

package eu.betaas.taas.contextmanager.linkeddata.semantics;

import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

import org.apache.log4j.Logger;

import com.google.gson.Gson;
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.Resource;
import com.hp.hpl.jena.rdf.model.ResourceFactory;
import com.hp.hpl.jena.sparql.vocabulary.FOAF;
import com.hp.hpl.jena.vocabulary.DCTerms;

import eu.betaas.taas.contextmanager.linkeddata.clients.TaaSCMClient;
import eu.betaas.taas.contextmanager.linkeddata.clients.Thing;

public class ThingsManager 
{
	private Logger logger= Logger.getLogger("betaas.taas");
	private TaaSCMClient cmClient;
	
	public ThingsManager ()
	{
		cmClient = TaaSCMClient.instance();
	}
	
	public String retrieveThingListAsDCAT()
	{
		Thing result;
		ByteArrayOutputStream stream = new ByteArrayOutputStream();
		String DCAT_NS = "http://www.w3.org/ns/dcat#";		
		Model instanceModel = ModelFactory.createDefaultModel();
		instanceModel.setNsPrefix("dc", DCTerms.NS);
		instanceModel.setNsPrefix("dcat", DCAT_NS);
		instanceModel.setNsPrefix("foaf", FOAF.NS);
				
		// Create the Catalog object
		Resource catalog = ResourceFactory.createResource(DCAT_NS + "Catalog");
		Resource betaas = instanceModel.createResource(FOAF.Project);
		betaas.addProperty(FOAF.homepage, instanceModel.createResource("http://www.betaas.eu/"));
		betaas.addProperty(FOAF.name, "BETaaS");
		Resource myCatalog = instanceModel.createResource("http://www.betaas.eu/instanceName", catalog);
		myCatalog.addProperty(DCTerms.title, "BETaaS Catalog");
		myCatalog.addProperty(DCTerms.description, "Catalog automatically created by a BETaaS instance about its Thing Services.");
		myCatalog.addProperty(DCTerms.issued, Calendar.getInstance().getTime().toString());
		myCatalog.addProperty(DCTerms.modified, Calendar.getInstance().getTime().toString());
		myCatalog.addProperty(DCTerms.language, instanceModel.createResource("http://id.loc.gov/vocabulary/iso639-1/en"));
		myCatalog.addProperty(DCTerms.license, instanceModel.createResource("http://creativecommons.org/licenses/by/3.0/"));
		myCatalog.addProperty(DCTerms.publisher, betaas);
		myCatalog.addProperty(FOAF.homepage, instanceModel.createResource("http://localhost:8080/InstanceManager"));
		
		for (String thingService : cmClient.getThingServices()) {
			result = cmClient.getFullMeasurement(thingService);
			
			// Create Dataset
			Resource dataset = ResourceFactory.createResource(DCAT_NS + "Dataset");
			Property dcatDataset = ResourceFactory.createProperty(DCAT_NS, "dataset");
			Resource myDataset = instanceModel.createResource("http://www.betaas.eu/instanceName/" + thingService, dataset);
			myDataset.addProperty(DCTerms.title, thingService);
			myDataset.addProperty(DCTerms.description, result.getMeasurement() + " sensor attached to the BETaaS instance");
			myDataset.addProperty(DCTerms.issued, Calendar.getInstance().getTime().toString());
			myDataset.addProperty(DCTerms.modified, Calendar.getInstance().getTime().toString());
			myDataset.addProperty(DCTerms.language, instanceModel.createResource("http://id.loc.gov/vocabulary/iso639-1/en"));
			myDataset.addProperty(DCTerms.accrualPeriodicity, instanceModel.createResource("http://purl.org/linked-data/sdmx/2009/code#freq-D"));
			myDataset.addProperty(DCTerms.publisher, betaas);
			myCatalog.addProperty(dcatDataset, myDataset);
			
			// Create CSV Distribution for Dataset
			Property dcatDistribution = ResourceFactory.createProperty(DCAT_NS, "distribution");
			Property dcatMediaType = ResourceFactory.createProperty(DCAT_NS, "mediaType");
			Property dcatDownload = ResourceFactory.createProperty(DCAT_NS, "downloadURL");
			Property dcatSize = ResourceFactory.createProperty(DCAT_NS, "byteSize");
			Resource distributionDs = ResourceFactory.createResource(DCAT_NS + "Distribution");
			Resource myDatasetDistribution = instanceModel.createResource("http://www.betaas.eu/instanceName/" + thingService + "/Distribution1", distributionDs);
			myDatasetDistribution.addProperty(DCTerms.title, "ThingServiceName Dataset in CSV");
			myDatasetDistribution.addProperty(DCTerms.description, "Data generated by the Thing Service " + thingService + " during the last 50 records, provided in CSV format.");
			myDatasetDistribution.addProperty(DCTerms.issued, Calendar.getInstance().getTime().toString());
			myDatasetDistribution.addProperty(DCTerms.modified, Calendar.getInstance().getTime().toString());
			myDatasetDistribution.addProperty(DCTerms.license, instanceModel.createResource("http://creativecommons.org/licenses/by/3.0/"));
			myDatasetDistribution.addProperty(dcatMediaType, "text/csv");
			myDatasetDistribution.addProperty(dcatDownload, instanceModel.createResource("http://localhost:8080/dataset/" + thingService));
			myDatasetDistribution.addProperty(dcatSize, "1024");
			myDataset.addProperty(dcatDistribution, myDatasetDistribution);
		}
		
		// Write the results
		instanceModel.write(stream, "RDF/XML-ABBREV");
		return stream.toString();
	}
	
	public String retrieveThingListAsJSON() {
		List<Thing> things = new ArrayList<Thing>();
		TaaSCMClient cmClient = TaaSCMClient.instance();
		
		for (String thingService : cmClient.getThingServices()) {
			things.add(cmClient.getFullMeasurement(thingService));
		}
		
		return new Gson().toJson(things);
	}
	
	public void updateNewDcatModel(String idThingService)
	{
		// TODO at the moment we can create a new one
	}
	
	public void updateRemoveDcatModel(String idThingService)
	{
		// TODO at the moment we can create a new one
	}
}