2 * ============LICENSE_START=======================================================
3 * Copyright (C) 2016-2018 Ericsson. All rights reserved.
4 * Modifications Copyright (C) 2019 Nordix Foundation.
5 * ================================================================================
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
18 * SPDX-License-Identifier: Apache-2.0
19 * ============LICENSE_END=========================================================
22 package org.onap.policy.apex.plugins.event.protocol.yaml;
24 import java.util.ArrayList;
25 import java.util.LinkedHashMap;
26 import java.util.List;
29 import org.onap.policy.apex.context.SchemaHelper;
30 import org.onap.policy.apex.context.impl.schema.SchemaHelperFactory;
31 import org.onap.policy.apex.model.basicmodel.service.ModelService;
32 import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
33 import org.onap.policy.apex.model.eventmodel.concepts.AxEvents;
34 import org.onap.policy.apex.model.eventmodel.concepts.AxField;
35 import org.onap.policy.apex.service.engine.event.ApexEvent;
36 import org.onap.policy.apex.service.engine.event.ApexEventException;
37 import org.onap.policy.apex.service.engine.event.ApexEventProtocolConverter;
38 import org.onap.policy.apex.service.engine.event.ApexEventRuntimeException;
39 import org.onap.policy.apex.service.parameters.eventprotocol.EventProtocolParameters;
40 import org.slf4j.ext.XLogger;
41 import org.slf4j.ext.XLoggerFactory;
42 import org.yaml.snakeyaml.DumperOptions.FlowStyle;
43 import org.yaml.snakeyaml.Yaml;
46 * The Class Apex2YamlEventConverter converts {@link ApexEvent} instances to and from YAML string representations of
49 * @author Liam Fallon (liam.fallon@ericsson.com)
51 public class Apex2YamlEventConverter implements ApexEventProtocolConverter {
52 private static final XLogger LOGGER = XLoggerFactory.getXLogger(Apex2YamlEventConverter.class);
54 // The parameters for the YAML event protocol
55 private YamlEventProtocolParameters yamlPars;
61 public void init(final EventProtocolParameters parameters) {
62 // Check and get the YAML parameters
63 if (!(parameters instanceof YamlEventProtocolParameters)) {
64 final String errorMessage = "specified consumer properties are not applicable to the YAML event protocol";
65 LOGGER.warn(errorMessage);
66 throw new ApexEventRuntimeException(errorMessage);
69 yamlPars = (YamlEventProtocolParameters) parameters;
76 public List<ApexEvent> toApexEvent(final String eventName, final Object eventObject) throws ApexEventException {
77 // Check the event eventObject
78 if (eventObject == null) {
79 LOGGER.warn("event processing failed, event is null");
80 throw new ApexEventException("event processing failed, event is null");
83 // Cast the event to a string, if our conversion is correctly configured, this cast should
85 if (!(eventObject instanceof String)) {
86 final String errorMessage = "error converting event \"" + eventObject + "\" to a string";
87 LOGGER.debug(errorMessage);
88 throw new ApexEventException(errorMessage);
91 final String yamlEventString = (String) eventObject;
93 // The list of events we will return
94 final List<ApexEvent> eventList = new ArrayList<>();
96 // Convert the YAML document string into an object
97 Object yamlObject = new Yaml().load(yamlEventString);
99 // If the incoming YAML did not create a map it is a primitive type or a collection so we
100 // convert it into a map for processing
102 if (yamlObject instanceof Map) {
103 // We already have a map so just cast the object
104 yamlMap = (Map<?, ?>) yamlObject;
106 // Create a single entry map, new map creation and assignment is to avoid a
107 // type checking warning
108 LinkedHashMap<String, Object> newYamlMap = new LinkedHashMap<>();
109 newYamlMap.put(yamlPars.getYamlFieldName(), yamlObject);
110 yamlMap = newYamlMap;
114 eventList.add(yamlMap2ApexEvent(eventName, yamlMap));
115 } catch (final Exception e) {
116 final String errorString = "Failed to unmarshal YAML event: " + e.getMessage() + ", event="
118 LOGGER.warn(errorString, e);
119 throw new ApexEventException(errorString, e);
122 // Return the list of events we have unmarshalled
130 public Object fromApexEvent(final ApexEvent apexEvent) throws ApexEventException {
131 // Check the Apex event
132 if (apexEvent == null) {
133 LOGGER.warn("event processing failed, Apex event is null");
134 throw new ApexEventException("event processing failed, Apex event is null");
137 // Get the event definition for the event from the model service
138 final AxEvent eventDefinition = ModelService.getModel(AxEvents.class).get(apexEvent.getName(),
139 apexEvent.getVersion());
141 // Create a map for output of the APEX event to YAML
142 LinkedHashMap<String, Object> yamlMap = new LinkedHashMap<>();
144 yamlMap.put(ApexEvent.NAME_HEADER_FIELD, apexEvent.getName());
145 yamlMap.put(ApexEvent.VERSION_HEADER_FIELD, apexEvent.getVersion());
146 yamlMap.put(ApexEvent.NAMESPACE_HEADER_FIELD, apexEvent.getNameSpace());
147 yamlMap.put(ApexEvent.SOURCE_HEADER_FIELD, apexEvent.getSource());
148 yamlMap.put(ApexEvent.TARGET_HEADER_FIELD, apexEvent.getTarget());
150 if (apexEvent.getExceptionMessage() != null) {
151 yamlMap.put(ApexEvent.EXCEPTION_MESSAGE_HEADER_FIELD, apexEvent.getExceptionMessage());
154 for (final AxField eventField : eventDefinition.getFields()) {
155 final String fieldName = eventField.getKey().getLocalName();
157 if (!apexEvent.containsKey(fieldName)) {
158 if (!eventField.getOptional()) {
159 final String errorMessage = "error parsing " + eventDefinition.getId() + " event to Json. "
160 + "Field \"" + fieldName + "\" is missing, but is mandatory. Fields: " + apexEvent;
161 LOGGER.debug(errorMessage);
162 throw new ApexEventRuntimeException(errorMessage);
167 yamlMap.put(fieldName, apexEvent.get(fieldName));
170 // Use Snake YAML to convert the APEX event to YAML
171 Yaml yaml = new Yaml();
172 return yaml.dumpAs(yamlMap, null, FlowStyle.BLOCK);
176 * This method converts a YAML map into an Apex event.
178 * @param eventName the name of the event
179 * @param yamlMap the YAML map that holds the event
180 * @return the apex event that we have converted the JSON object into
181 * @throws ApexEventException thrown on unmarshaling exceptions
183 private ApexEvent yamlMap2ApexEvent(final String eventName, final Map<?, ?> yamlMap) throws ApexEventException {
184 // Process the mandatory Apex header
185 final ApexEvent apexEvent = processApexEventHeader(eventName, yamlMap);
187 // Get the event definition for the event from the model service
188 final AxEvent eventDefinition = ModelService.getModel(AxEvents.class).get(apexEvent.getName(),
189 apexEvent.getVersion());
191 // Iterate over the input fields in the event
192 for (final AxField eventField : eventDefinition.getFields()) {
193 final String fieldName = eventField.getKey().getLocalName();
194 if (!yamlMap.containsKey(fieldName)) {
195 if (!eventField.getOptional()) {
196 final String errorMessage = "error parsing " + eventDefinition.getId() + " event from Json. "
197 + "Field \"" + fieldName + "\" is missing, but is mandatory.";
198 LOGGER.debug(errorMessage);
199 throw new ApexEventException(errorMessage);
204 final Object fieldValue = getYamlField(yamlMap, fieldName, null, !eventField.getOptional());
206 if (fieldValue != null) {
207 // Get the schema helper
208 final SchemaHelper fieldSchemaHelper = new SchemaHelperFactory().createSchemaHelper(eventField.getKey(),
209 eventField.getSchema());
210 apexEvent.put(fieldName, fieldSchemaHelper.createNewInstance(fieldValue));
212 apexEvent.put(fieldName, null);
220 * This method processes the event header of an Apex event.
222 * @param eventName the name of the event
223 * @param yamlMap the YAML map that holds the event
224 * @return an apex event constructed using the header fields of the event
225 * @throws ApexEventRuntimeException the apex event runtime exception
226 * @throws ApexEventException on invalid events with missing header fields
228 private ApexEvent processApexEventHeader(final String eventName, final Map<?, ?> yamlMap)
229 throws ApexEventException {
230 String name = getYamlStringField(yamlMap, ApexEvent.NAME_HEADER_FIELD, yamlPars.getNameAlias(),
231 ApexEvent.NAME_REGEXP, false);
233 // Check that an event name has been specified
234 if (name == null && eventName == null) {
235 throw new ApexEventRuntimeException(
236 "event received without mandatory parameter \"name\" on configuration or on event");
239 // Check if an event name was specified on the event parameters
240 if (eventName != null) {
241 if (name != null && !eventName.equals(name)) {
242 LOGGER.warn("The incoming event name \"{}\" does not match the configured event name \"{}\", "
243 + "using configured event name", name, eventName);
248 // Now, find the event definition in the model service. If version is null, the newest event
249 // definition in the model service is used
250 String version = getYamlStringField(yamlMap, ApexEvent.VERSION_HEADER_FIELD, yamlPars.getVersionAlias(),
251 ApexEvent.VERSION_REGEXP, false);
252 final AxEvent eventDefinition = ModelService.getModel(AxEvents.class).get(name, version);
253 if (eventDefinition == null) {
254 throw new ApexEventRuntimeException("an event definition for an event named \"" + name
255 + "\" with version \"" + version + "\" not found in Apex model");
258 // Use the defined event version if no version is specified on the incoming fields
259 if (version == null) {
260 version = eventDefinition.getKey().getVersion();
263 String namespace = getEventHeaderNamespace(yamlMap, name, eventDefinition);
265 String source = getEventHeaderSource(yamlMap, eventDefinition);
267 String target = getHeaderTarget(yamlMap, eventDefinition);
269 return new ApexEvent(name, version, namespace, source, target);
273 * Get the event header name space.
275 * @param yamlMap the YAML map to read from
276 * @param eventDefinition the event definition
277 * @return the event header name space
279 private String getEventHeaderNamespace(final Map<?, ?> yamlMap, String name, final AxEvent eventDefinition) {
280 // Check the name space is OK if it is defined, if not, use the name space from the model
281 String namespace = getYamlStringField(yamlMap, ApexEvent.NAMESPACE_HEADER_FIELD, yamlPars.getNameSpaceAlias(),
282 ApexEvent.NAMESPACE_REGEXP, false);
283 if (namespace != null) {
284 if (!namespace.equals(eventDefinition.getNameSpace())) {
285 throw new ApexEventRuntimeException("namespace \"" + namespace + "\" on event \"" + name
286 + "\" does not match namespace \"" + eventDefinition.getNameSpace()
287 + "\" for that event in the Apex model");
290 namespace = eventDefinition.getNameSpace();
296 * Get the event header source.
298 * @param yamlMap the YAML map to read from
299 * @param eventDefinition the event definition
300 * @return the event header source
302 private String getEventHeaderSource(final Map<?, ?> yamlMap, final AxEvent eventDefinition) {
303 // For source, use the defined source only if the source is not found on the incoming event
304 String source = getYamlStringField(yamlMap, ApexEvent.SOURCE_HEADER_FIELD, yamlPars.getSourceAlias(),
305 ApexEvent.SOURCE_REGEXP, false);
306 if (source == null) {
307 source = eventDefinition.getSource();
313 * Get the event header target.
315 * @param yamlMap the YAML map to read from
316 * @param eventDefinition the event definition
317 * @return the event header target
319 private String getHeaderTarget(final Map<?, ?> yamlMap, final AxEvent eventDefinition) {
320 // For target, use the defined source only if the source is not found on the incoming event
321 String target = getYamlStringField(yamlMap, ApexEvent.TARGET_HEADER_FIELD, yamlPars.getTargetAlias(),
322 ApexEvent.TARGET_REGEXP, false);
323 if (target == null) {
324 target = eventDefinition.getTarget();
330 * This method gets an event string field from a JSON object.
332 * @param yamlMap the YAML containing the YAML representation of the incoming event
333 * @param fieldName the field name to find in the event
334 * @param fieldAlias the alias for the field to find in the event, overrides the field name if it is not null
335 * @param fieldRegexp the regular expression to check the field against for validity
336 * @param mandatory true if the field is mandatory
337 * @return the value of the field in the JSON object or null if the field is optional
338 * @throws ApexEventRuntimeException the apex event runtime exception
340 private String getYamlStringField(final Map<?, ?> yamlMap, final String fieldName, final String fieldAlias,
341 final String fieldRegexp, final boolean mandatory) {
342 // Get the YAML field for the string field
343 final Object yamlField = getYamlField(yamlMap, fieldName, fieldAlias, mandatory);
345 // Null strings are allowed
346 if (yamlField == null) {
350 if (!(yamlField instanceof String)) {
351 // The element is not a string so throw an error
352 throw new ApexEventRuntimeException("field \"" + fieldName + "\" with type \""
353 + yamlField.getClass().getName() + "\" is not a string value");
356 final String fieldValueString = (String) yamlField;
358 // Is regular expression checking required
359 if (fieldRegexp == null) {
360 return fieldValueString;
363 // Check the event field against its regular expression
364 if (!fieldValueString.matches(fieldRegexp)) {
365 throw new ApexEventRuntimeException(
366 "field \"" + fieldName + "\" with value \"" + fieldValueString + "\" is invalid");
369 return fieldValueString;
373 * This method gets an event field from a YAML object.
375 * @param yamlMap the YAML containing the YAML representation of the incoming event
376 * @param fieldName the field name to find in the event
377 * @param fieldAlias the alias for the field to find in the event, overrides the field name if it is not null
378 * @param mandatory true if the field is mandatory
379 * @return the value of the field in the YAML object or null if the field is optional
380 * @throws ApexEventRuntimeException the apex event runtime exception
382 private Object getYamlField(final Map<?, ?> yamlMap, final String fieldName, final String fieldAlias,
383 final boolean mandatory) {
385 // Check if we should use the alias for this field
386 String fieldToFind = fieldName;
387 if (fieldAlias != null) {
388 fieldToFind = fieldAlias;
391 // Get the event field
392 final Object eventElement = yamlMap.get(fieldToFind);
393 if (eventElement == null) {
397 throw new ApexEventRuntimeException("mandatory field \"" + fieldToFind + "\" is missing");