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;
30 import javax.xml.XMLConstants;
31 import javax.xml.bind.JAXBContext;
32 import javax.xml.bind.JAXBElement;
33 import javax.xml.bind.JAXBException;
34 import javax.xml.bind.Marshaller;
35 import javax.xml.bind.Unmarshaller;
36 import javax.xml.transform.stream.StreamSource;
37 import javax.xml.validation.Schema;
38 import javax.xml.validation.SchemaFactory;
40 import org.onap.policy.apex.plugins.event.protocol.xml.jaxb.ObjectFactory;
41 import org.onap.policy.apex.plugins.event.protocol.xml.jaxb.XMLApexEvent;
42 import org.onap.policy.apex.plugins.event.protocol.xml.jaxb.XMLApexEventData;
43 import org.onap.policy.apex.service.engine.event.ApexEvent;
44 import org.onap.policy.apex.service.engine.event.ApexEventException;
45 import org.onap.policy.apex.service.engine.event.ApexEventProtocolConverter;
46 import org.onap.policy.apex.service.engine.event.ApexEventRuntimeException;
47 import org.onap.policy.apex.service.parameters.eventprotocol.EventProtocolParameters;
48 import org.onap.policy.common.utils.resources.ResourceUtils;
49 import org.slf4j.ext.XLogger;
50 import org.slf4j.ext.XLoggerFactory;
51 import org.xml.sax.SAXException;
54 * The Class Apex2XMLEventConverter converts {@link ApexEvent} instances into string instances of {@link XMLApexEvent}
55 * that are XML representations of Apex events defined in JAXB.
57 * @author Liam Fallon (liam.fallon@ericsson.com)
59 public final class Apex2XmlEventConverter implements ApexEventProtocolConverter {
60 private static final XLogger LOGGER = XLoggerFactory.getXLogger(Apex2XmlEventConverter.class);
62 private static final String MODEL_SCHEMA_NAME = "xml/apex-event.xsd";
64 // XML Unmarshaller and marshaller and object factory for events
65 private Unmarshaller unmarshaller;
66 private Marshaller marshaller;
67 private ObjectFactory objectFactory = new ObjectFactory();
70 * Constructor to create the Apex to XML converter.
72 * @throws ApexEventException the apex event exception
74 public Apex2XmlEventConverter() throws ApexEventException {
76 final URL schemaUrl = ResourceUtils.getUrlResource(MODEL_SCHEMA_NAME);
77 final Schema apexEventSchema =
78 SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(schemaUrl);
80 final JAXBContext jaxbContext = JAXBContext.newInstance(XMLApexEvent.class);
82 // Set up the unmarshaller to carry out validation
83 unmarshaller = jaxbContext.createUnmarshaller();
84 unmarshaller.setEventHandler(new javax.xml.bind.helpers.DefaultValidationEventHandler());
85 unmarshaller.setSchema(apexEventSchema);
87 // Set up the marshaller
88 marshaller = jaxbContext.createMarshaller();
89 marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
90 marshaller.setSchema(apexEventSchema);
91 } catch (JAXBException | SAXException e) {
92 LOGGER.error("Unable to set up marshalling and unmarshalling for XML events", e);
93 throw new ApexEventException("Unable to set up marshalling and unmarshalling for XML events", e);
101 public void init(final EventProtocolParameters parameters) {
102 // No initialization necessary on this class
109 public List<ApexEvent> toApexEvent(final String eventName, final Object eventObject) throws ApexEventException {
110 // Check the XML event
111 if (eventObject == null) {
112 LOGGER.warn("event processing failed, XML event is null");
113 throw new ApexEventException("event processing failed, XML event is null");
116 // Cast the event to a string, if our conversion is correctly configured, this cast should always work
117 String xmlEventString = null;
119 xmlEventString = (String) eventObject;
120 } catch (final Exception e) {
121 final String errorMessage = "error converting event \"" + eventObject + "\" to a string";
122 LOGGER.debug(errorMessage, e);
123 throw new ApexEventRuntimeException(errorMessage, e);
127 XMLApexEvent xmlApexEvent = null;
129 // Use JAXB to read and verify the event from the XML string
131 final StreamSource source = new StreamSource(new ByteArrayInputStream(xmlEventString.getBytes()));
132 final JAXBElement<XMLApexEvent> rootElement = unmarshaller.unmarshal(source, XMLApexEvent.class);
133 xmlApexEvent = rootElement.getValue();
134 } catch (final JAXBException e) {
135 LOGGER.warn("Unable to unmarshal Apex XML event\n" + xmlEventString, e);
136 throw new ApexEventException("Unable to unmarshal Apex XML event\n" + xmlEventString, e);
139 // Create the Apex event
140 final ApexEvent apexEvent = new ApexEvent(xmlApexEvent.getName(), xmlApexEvent.getVersion(),
141 xmlApexEvent.getNameSpace(), xmlApexEvent.getSource(), xmlApexEvent.getTarget());
143 // Set the data on the apex event
144 for (final XMLApexEventData xmlData : xmlApexEvent.getData()) {
145 apexEvent.put(xmlData.getKey(), xmlData.getValue());
148 // Return the event in a single element
149 final ArrayList<ApexEvent> eventList = new ArrayList<>();
150 eventList.add(apexEvent);
158 public String fromApexEvent(final ApexEvent apexEvent) throws ApexEventException {
159 // Check the Apex event
160 if (apexEvent == null) {
161 LOGGER.warn("event processing failed, Apex event is null");
162 throw new ApexEventException("event processing failed, Apex event is null");
165 // Get the Apex event data
166 final List<XMLApexEventData> xmlDataList = new ArrayList<>();
169 for (final Entry<String, Object> apexDataEntry : apexEvent.entrySet()) {
170 // Add an XML event data item
171 if (apexDataEntry.getValue() != null) {
172 xmlDataList.add(new XMLApexEventData(apexDataEntry.getKey(), apexDataEntry.getValue().toString()));
174 xmlDataList.add(new XMLApexEventData(apexDataEntry.getKey(), ""));
177 } catch (final Exception e) {
178 LOGGER.warn("Unable to transfer Apex event data to XML\n" + apexEvent, e);
179 throw new ApexEventException("Unable to transfer Apex event data to XML\n" + apexEvent, e);
182 // Create the XML event
183 final XMLApexEvent xmlApexEvent = new XMLApexEvent(apexEvent.getName(), apexEvent.getVersion(),
184 apexEvent.getNameSpace(), apexEvent.getSource(), apexEvent.getTarget(), xmlDataList);
186 // Write the event into a DOM document
188 // Marshal the event into XML
189 final StringWriter writer = new StringWriter();
190 marshaller.marshal(objectFactory.createXmlApexEvent(xmlApexEvent), writer);
192 // Return the event as XML in a string
193 return writer.toString();
194 } catch (final JAXBException e) {
195 LOGGER.warn("Unable to unmarshal Apex event to XML\n" + apexEvent, e);
196 throw new ApexEventException("Unable to unmarshal Apex event to XML\n" + apexEvent, e);