[593849]: src / edu / teco / deps / agent / processors / TarqlProcessor.java History

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TarqlProcessor.java    50 lines (39 with data), 1.6 kB 

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package edu.teco.deps.agent.processors;



import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.Reader;

import java.io.Writer;



import org.deri.tarql.CSVQueryExecutionFactory;

import org.deri.tarql.CSVToValues;

import org.deri.tarql.TarqlParser;

import org.deri.tarql.TarqlQuery;



import com.hp.hpl.jena.query.Query;

import com.hp.hpl.jena.query.QueryExecution;

import com.hp.hpl.jena.rdf.model.Model;

import com.hp.hpl.jena.rdf.model.ModelFactory;

import com.hp.hpl.jena.sparql.algebra.table.TableData;



public class TarqlProcessor implements Processor {



	TarqlQuery query;

	

	public TarqlProcessor(Reader queryReader) throws FileNotFoundException {

		TarqlParser parser = new TarqlParser(queryReader);

		query = parser.getResult();

	}



	public void process(Reader reader, Writer writer) throws IOException {

		CSVToValues transformer = new CSVToValues(reader, false);

		TableData table = transformer.read();

		

		Model resultModel = ModelFactory.createDefaultModel();

		for (Query q: query.getQueries()) {

			// Clone the damn query first, as CSVQueryExecutionFactory is going to alter it 

			q = q.cloneQuery();

			

			Model previousResults = ModelFactory.createDefaultModel();

			previousResults.add(resultModel);

			CSVQueryExecutionFactory.setPreviousResults(previousResults);

			QueryExecution execution = CSVQueryExecutionFactory.create(table, q);

			resultModel.setNsPrefixes(resultModel);

			execution.execConstruct(resultModel);

			CSVQueryExecutionFactory.resetPreviousResults();

		}



		resultModel.write(writer, "N-TRIPLE", query.getPrologue().getBaseURI());

		writer.flush();

	}

}