org.eclipse.rdf4j.rio.RDFHandler Maven / Gradle / Ivy

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/*******************************************************************************
 * 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.
 *******************************************************************************/
package org.eclipse.rdf4j.rio;

import org.eclipse.rdf4j.model.Statement;

/**
 * An interface defining methods related to RDF data handling. RDFHandler is both used as a
 * "consumer" and as a "producer" interface. As such it can be used both as an interface for receiving RDF
 * data, for example by listening to the results of an RDF parser, and as an interface for reporting RDF data,
 * for example to an object that serializes RDF data to an RDF/XML document.
 */
public interface RDFHandler {

	/**
	 * Signals the start of the RDF data. This method is called before any data is reported.
	 * 
	 * @throws RDFHandlerException
	 *         If the RDF handler has encountered an unrecoverable error.
	 */
	public void startRDF()
		throws RDFHandlerException;

	/**
	 * Signals the end of the RDF data. This method is called when all data has been reported.
	 * 
	 * @throws RDFHandlerException
	 *         If the RDF handler has encountered an unrecoverable error.
	 */
	public void endRDF()
		throws RDFHandlerException;

	/**
	 * Handles a namespace declaration/definition. A namespace declaration associates a (short) prefix string
	 * with the namespace's URI. The prefix for default namespaces, which do not have an associated prefix,
	 * are represented as empty strings.
	 * 
	 * @param prefix
	 *        The prefix for the namespace, or an empty string in case of a default namespace.
	 * @param uri
	 *        The URI that the prefix maps to.
	 * @throws RDFHandlerException
	 *         If the RDF handler has encountered an unrecoverable error.
	 */
	public void handleNamespace(String prefix, String uri)
		throws RDFHandlerException;

	/**
	 * Handles a statement.
	 * 
	 * @param st
	 *        The statement.
	 * @throws RDFHandlerException
	 *         If the RDF handler has encountered an unrecoverable error.
	 */
	public void handleStatement(Statement st)
		throws RDFHandlerException;

	/**
	 * Handles a comment.
	 * 
	 * @param comment
	 *        The comment.
	 * @throws RDFHandlerException
	 *         If the RDF handler has encountered an unrecoverable error.
	 */
	public void handleComment(String comment)
		throws RDFHandlerException;
}