2 * ============LICENSE_START=======================================================
3 * Copyright (C) 2016-2018 Ericsson. All rights reserved.
4 * ================================================================================
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
17 * SPDX-License-Identifier: Apache-2.0
18 * ============LICENSE_END=========================================================
21 package org.onap.policy.apex.plugins.event.protocol.xml;
23 import java.io.ByteArrayInputStream;
24 import java.io.StringWriter;
26 import java.util.ArrayList;
27 import java.util.List;
28 import java.util.Map.Entry;
29 import javax.xml.XMLConstants;
30 import javax.xml.bind.JAXBContext;
31 import javax.xml.bind.JAXBElement;
32 import javax.xml.bind.JAXBException;
33 import javax.xml.bind.Marshaller;
34 import javax.xml.bind.Unmarshaller;
35 import javax.xml.transform.stream.StreamSource;
36 import javax.xml.validation.Schema;
37 import javax.xml.validation.SchemaFactory;
38 import org.onap.policy.apex.plugins.event.protocol.xml.jaxb.ObjectFactory;
39 import org.onap.policy.apex.plugins.event.protocol.xml.jaxb.XMLApexEvent;
40 import org.onap.policy.apex.plugins.event.protocol.xml.jaxb.XMLApexEventData;
41 import org.onap.policy.apex.service.engine.event.ApexEvent;
42 import org.onap.policy.apex.service.engine.event.ApexEventException;
43 import org.onap.policy.apex.service.engine.event.ApexEventProtocolConverter;
44 import org.onap.policy.apex.service.engine.event.ApexEventRuntimeException;
45 import org.onap.policy.apex.service.parameters.eventprotocol.EventProtocolParameters;
46 import org.onap.policy.common.utils.resources.ResourceUtils;
47 import org.slf4j.ext.XLogger;
48 import org.slf4j.ext.XLoggerFactory;
49 import org.xml.sax.SAXException;
52 * The Class Apex2XMLEventConverter converts {@link ApexEvent} instances into string instances of {@link XMLApexEvent}
53 * that are XML representations of Apex events defined in JAXB.
55 * @author Liam Fallon (liam.fallon@ericsson.com)
57 public final class Apex2XmlEventConverter implements ApexEventProtocolConverter {
58 private static final XLogger LOGGER = XLoggerFactory.getXLogger(Apex2XmlEventConverter.class);
60 private static final String MODEL_SCHEMA_NAME = "xml/apex-event.xsd";
62 // XML Unmarshaller and marshaller and object factory for events
63 private Unmarshaller unmarshaller;
64 private Marshaller marshaller;
65 private ObjectFactory objectFactory = new ObjectFactory();
68 * Constructor to create the Apex to XML converter.
70 * @throws ApexEventException the apex event exception
72 public Apex2XmlEventConverter() throws ApexEventException {
74 final URL schemaUrl = ResourceUtils.getUrlResource(MODEL_SCHEMA_NAME);
75 final Schema apexEventSchema =
76 SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(schemaUrl);
78 final JAXBContext jaxbContext = JAXBContext.newInstance(XMLApexEvent.class);
80 // Set up the unmarshaller to carry out validation
81 unmarshaller = jaxbContext.createUnmarshaller();
82 unmarshaller.setEventHandler(new javax.xml.bind.helpers.DefaultValidationEventHandler());
83 unmarshaller.setSchema(apexEventSchema);
85 // Set up the marshaller
86 marshaller = jaxbContext.createMarshaller();
87 marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
88 marshaller.setSchema(apexEventSchema);
89 } catch (JAXBException | SAXException e) {
90 LOGGER.error("Unable to set up marshalling and unmarshalling for XML events", e);
91 throw new ApexEventException("Unable to set up marshalling and unmarshalling for XML events", e);
99 public void init(final EventProtocolParameters parameters) {
100 // No initialization necessary on this class
107 public List<ApexEvent> toApexEvent(final String eventName, final Object eventObject) throws ApexEventException {
108 // Check the XML event
109 if (eventObject == null) {
110 LOGGER.warn("event processing failed, XML event is null");
111 throw new ApexEventException("event processing failed, XML event is null");
114 // Cast the event to a string, if our conversion is correctly configured, this cast should always work
115 String xmlEventString = null;
117 xmlEventString = (String) eventObject;
118 } catch (final Exception e) {
119 final String errorMessage = "error converting event \"" + eventObject + "\" to a string";
120 LOGGER.debug(errorMessage, e);
121 throw new ApexEventRuntimeException(errorMessage, e);
125 XMLApexEvent xmlApexEvent = null;
127 // Use JAXB to read and verify the event from the XML string
129 final StreamSource source = new StreamSource(new ByteArrayInputStream(xmlEventString.getBytes()));
130 final JAXBElement<XMLApexEvent> rootElement = unmarshaller.unmarshal(source, XMLApexEvent.class);
131 xmlApexEvent = rootElement.getValue();
132 } catch (final JAXBException e) {
133 LOGGER.warn("Unable to unmarshal Apex XML event\n" + xmlEventString, e);
134 throw new ApexEventException("Unable to unmarshal Apex XML event\n" + xmlEventString, e);
137 // Create the Apex event
138 final ApexEvent apexEvent = new ApexEvent(xmlApexEvent.getName(), xmlApexEvent.getVersion(),
139 xmlApexEvent.getNameSpace(), xmlApexEvent.getSource(), xmlApexEvent.getTarget());
141 // Set the data on the apex event
142 for (final XMLApexEventData xmlData : xmlApexEvent.getData()) {
143 apexEvent.put(xmlData.getKey(), xmlData.getValue());
146 // Return the event in a single element
147 final ArrayList<ApexEvent> eventList = new ArrayList<>();
148 eventList.add(apexEvent);
156 public String fromApexEvent(final ApexEvent apexEvent) throws ApexEventException {
157 // Check the Apex event
158 if (apexEvent == null) {
159 LOGGER.warn("event processing failed, Apex event is null");
160 throw new ApexEventException("event processing failed, Apex event is null");
163 // Get the Apex event data
164 final List<XMLApexEventData> xmlDataList = new ArrayList<>();
167 for (final Entry<String, Object> apexDataEntry : apexEvent.entrySet()) {
168 // Add an XML event data item
169 if (apexDataEntry.getValue() != null) {
170 xmlDataList.add(new XMLApexEventData(apexDataEntry.getKey(), apexDataEntry.getValue().toString()));
172 xmlDataList.add(new XMLApexEventData(apexDataEntry.getKey(), ""));
175 } catch (final Exception e) {
176 LOGGER.warn("Unable to transfer Apex event data to XML\n" + apexEvent, e);
177 throw new ApexEventException("Unable to transfer Apex event data to XML\n" + apexEvent, e);
180 // Create the XML event
181 final XMLApexEvent xmlApexEvent = new XMLApexEvent(apexEvent.getName(), apexEvent.getVersion(),
182 apexEvent.getNameSpace(), apexEvent.getSource(), apexEvent.getTarget(), xmlDataList);
184 // Write the event into a DOM document
186 // Marshal the event into XML
187 final StringWriter writer = new StringWriter();
188 marshaller.marshal(objectFactory.createXmlApexEvent(xmlApexEvent), writer);
190 // Return the event as XML in a string
191 return writer.toString();
192 } catch (final JAXBException e) {
193 LOGGER.warn("Unable to unmarshal Apex event to XML\n" + apexEvent, e);
194 throw new ApexEventException("Unable to unmarshal Apex event to XML\n" + apexEvent, e);