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 com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS; 021import static org.fcrepo.event.serialization.JsonLDEventMessage.from; 022import static org.slf4j.LoggerFactory.getLogger; 023 024import com.fasterxml.jackson.core.JsonProcessingException; 025import com.fasterxml.jackson.databind.ObjectMapper; 026import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule; 027import org.fcrepo.kernel.api.observer.FedoraEvent; 028import org.slf4j.Logger; 029 030/** 031 * Some serialization utilities for FedoraEvent objects 032 * @author acoburn 033 */ 034public class JsonLDSerializer implements EventSerializer { 035 036 private static final Logger LOGGER = getLogger(JsonLDSerializer.class); 037 038 private static final ObjectMapper MAPPER = new ObjectMapper(); 039 040 /** 041 * Create a new JSON-LD Event Serializer 042 */ 043 public JsonLDSerializer() { 044 // newer versions of jackson rename this to `JavaTimeModule` 045 MAPPER.registerModule(new JavaTimeModule()); 046 MAPPER.configure(WRITE_DATES_AS_TIMESTAMPS, false); 047 } 048 049 /** 050 * Serialize a FedoraEvent into a JSON String 051 * @param evt the Fedora event 052 * @return a JSON string 053 */ 054 @Override 055 public String serialize(final FedoraEvent evt) { 056 try { 057 return MAPPER.writeValueAsString(from(evt)); 058 } catch (final JsonProcessingException ex) { 059 LOGGER.error("Error processing JSON: {}", ex.getMessage()); 060 return null; 061 } 062 } 063}