STRUUID.java

/*******************************************************************************
 * Copyright (c) 2015 Eclipse RDF4J contributors, Aduna, and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Distribution License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *******************************************************************************/
package org.eclipse.rdf4j.query.algebra.evaluation.function.rdfterm;

import org.eclipse.rdf4j.model.Literal;
import org.eclipse.rdf4j.model.Value;
import org.eclipse.rdf4j.model.ValueFactory;
import org.eclipse.rdf4j.query.algebra.evaluation.ValueExprEvaluationException;
import org.eclipse.rdf4j.query.algebra.evaluation.function.Function;

/**
 * The SPARQL built-in {@link Function} UUID, as defined in
 * <a href="http://www.w3.org/TR/sparql11-query/#func-uuid">SPARQL Query Language for RDF</a>
 *
 * @author Jeen Broekstra
 */
public class STRUUID implements Function {

	@Override
	public String getURI() {
		return "STRUUID";
	}

	@Override
	public Literal evaluate(ValueFactory valueFactory, Value... args) throws ValueExprEvaluationException {
		if (args.length > 0) {
			throw new ValueExprEvaluationException("STRUUID requires 0 arguments, got " + args.length);
		}

		Literal literal = valueFactory.createLiteral(java.util.UUID.randomUUID().toString());

		return literal;
	}

	@Override
	public boolean mustReturnDifferentResult() {
		return true;
	}
}