Prefix.java

/*******************************************************************************
 * Copyright (c) 2018 Eclipse RDF4J contributors.
 *
 * 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.sparqlbuilder.core;

import org.eclipse.rdf4j.model.IRI;
import org.eclipse.rdf4j.sparqlbuilder.rdf.Iri;
import org.eclipse.rdf4j.sparqlbuilder.rdf.Rdf;

/**
 * A SPARQL Prefix declaration
 *
 * @see <a href="http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#prefNames"> SPARQL Prefix</a>
 */
public class Prefix implements QueryElement {
	private static final String PREFIX = "PREFIX";
	private final String label;
	private final Iri iri;

	Prefix(String alias, Iri iri) {
		this.label = alias;
		this.iri = iri;
	}

	Prefix(String alias, IRI iri) {
		this(alias, Rdf.iri(iri));
	}

	Iri getIri() {
		return iri;
	}

	String getLabel() {
		return label;
	}

	/**
	 * Create a prefixed IRI reference from this prefix
	 *
	 * @param localName the local part of the prefixed IRI
	 * @return a prefixed IRI reference, with this prefix's label as the base, and the given string for the local part
	 */
	public Iri iri(String localName) {
		return () -> label + ":" + localName;
	}

	@Override
	public String getQueryString() {
		return PREFIX + " " + label + ": " + iri.getQueryString();
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}

		if (obj == null) {
			return false;
		}

		if (!(obj instanceof Prefix)) {
			return false;
		}

		Prefix other = (Prefix) obj;
		if (label == null) {
			if (other.label != null) {
				return false;
			}
		} else if (!label.equals(other.label)) {
			return false;
		}
		if (iri == null) {
			if (other.iri != null) {
				return false;
			}
		} else if (!iri.equals(other.iri)) {
			return false;
		}

		return true;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((label == null) ? 0 : label.hashCode());
		result = prime * result + ((iri == null) ? 0 : iri.hashCode());
		return result;
	}
}