001/*
002 * Licensed to DuraSpace under one or more contributor license agreements.
003 * See the NOTICE file distributed with this work for additional information
004 * regarding copyright ownership.
005 *
006 * DuraSpace licenses this file to you under the Apache License,
007 * Version 2.0 (the "License"); you may not use this file except in
008 * compliance with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.fcrepo.event.serialization;
019
020import static java.nio.charset.StandardCharsets.UTF_8;
021import static org.apache.jena.rdf.model.ModelFactory.createDefaultModel;
022import static org.fcrepo.kernel.api.observer.OptionalValues.BASE_URL;
023
024import java.io.ByteArrayInputStream;
025
026import org.apache.jena.rdf.model.Model;
027import org.fcrepo.kernel.api.observer.FedoraEvent;
028
029/**
030 * A basic serialization API for Fedora events
031 * @author acoburn
032 * @author dbernstein
033 */
034public interface EventSerializer {
035
036    /**
037     * Convert an event to an Rdf Model
038     * @param evt the Fedora event
039     * @return an RDF model representing the event
040     */
041    static Model toModel(final FedoraEvent evt) {
042        final EventSerializer serializer = new JsonLDSerializer();
043        final String json = serializer.serialize(evt);
044        final Model model = createDefaultModel();
045        final String baseUrl = evt.getInfo().get(BASE_URL);
046        model.read(new ByteArrayInputStream(json.getBytes(UTF_8)), baseUrl + evt.getPath(), "JSON-LD");
047        return model;
048    }
049
050    /**
051     * Serialize a FedoraEvent into a JSON String
052     * @param evt the Fedora event
053     * @return a JSON string
054     */
055    String serialize(final FedoraEvent evt);
056}