CloudEvents support for cps-core

[cps.git] / cps-service / src / main / java / org / onap / cps / events / EventsPublisher.java

diff --git a/cps-service/src/main/java/org/onap/cps/events/EventsPublisher.java b/cps-service/src/main/java/org/onap/cps/events/EventsPublisher.java
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+++ b/cps-service/src/main/java/org/onap/cps/events/EventsPublisher.java
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+/*
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2022-2024 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.events;
+
+import io.cloudevents.CloudEvent;
+import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.common.header.Headers;
+import org.apache.kafka.common.header.internals.RecordHeaders;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.kafka.support.SendResult;
+import org.springframework.stereotype.Service;
+import org.springframework.util.SerializationUtils;
+
+/**
+ * EventsPublisher to publish events.
+ */
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class EventsPublisher<T> {
+
+    /**
+     * KafkaTemplate for legacy (non-cloud) events.
+     * Note: Cloud events should be used. This will be addressed as part of  https://jira.onap.org/browse/CPS-1717.
+     */
+    private final KafkaTemplate<String, T> legacyKafkaEventTemplate;
+
+    private final KafkaTemplate<String, CloudEvent> cloudEventKafkaTemplate;
+
+    /**
+     * Generic CloudEvent publisher.
+     *
+     * @param topicName valid topic name
+     * @param eventKey  message key
+     * @param event     message payload
+     */
+    public void publishCloudEvent(final String topicName, final String eventKey, final CloudEvent event) {
+        final CompletableFuture<SendResult<String, CloudEvent>> eventFuture =
+                cloudEventKafkaTemplate.send(topicName, eventKey, event);
+        eventFuture.whenComplete((result, e) -> {
+            if (e == null) {
+                log.debug("Successfully published event to topic : {} , Event : {}", result.getRecordMetadata().topic(),
+                        result.getProducerRecord().value());
+
+            } else {
+                log.error("Unable to publish event to topic : {} due to {}", topicName, e.getMessage());
+            }
+        });
+    }
+
+    /**
+     * Generic Event publisher.
+     * Note: Cloud events should be used. This will be addressed as part of  https://jira.onap.org/browse/CPS-1717.
+     *
+     * @param topicName valid topic name
+     * @param eventKey  message key
+     * @param event     message payload
+     */
+    public void publishEvent(final String topicName, final String eventKey, final T event) {
+        final CompletableFuture<SendResult<String, T>> eventFuture =
+                legacyKafkaEventTemplate.send(topicName, eventKey, event);
+        handleLegacyEventCallback(topicName, eventFuture);
+    }
+
+    /**
+     * Generic Event Publisher with headers.
+     *
+     * @param topicName    valid topic name
+     * @param eventKey     message key
+     * @param eventHeaders event headers
+     * @param event        message payload
+     */
+    public void publishEvent(final String topicName, final String eventKey, final Headers eventHeaders, final T event) {
+
+        final ProducerRecord<String, T> producerRecord =
+                new ProducerRecord<>(topicName, null, eventKey, event, eventHeaders);
+        final CompletableFuture<SendResult<String, T>> eventFuture = legacyKafkaEventTemplate.send(producerRecord);
+        handleLegacyEventCallback(topicName, eventFuture);
+    }
+
+    /**
+     * Generic Event Publisher with headers.
+     *
+     * @param topicName    valid topic name
+     * @param eventKey     message key
+     * @param eventHeaders map of event headers
+     * @param event        message payload
+     */
+    public void publishEvent(final String topicName, final String eventKey, final Map<String, Object> eventHeaders,
+            final T event) {
+
+        publishEvent(topicName, eventKey, convertToKafkaHeaders(eventHeaders), event);
+    }
+
+    private void handleLegacyEventCallback(final String topicName,
+            final CompletableFuture<SendResult<String, T>> eventFuture) {
+        eventFuture.whenComplete((result, e) -> {
+            if (e == null) {
+                log.debug("Successfully published event to topic : {} , Event : {}", result.getRecordMetadata().topic(),
+                        result.getProducerRecord().value());
+            } else {
+                log.error("Unable to publish event to topic : {} due to {}", topicName, e.getMessage());
+            }
+        });
+    }
+
+    private Headers convertToKafkaHeaders(final Map<String, Object> eventMessageHeaders) {
+        final Headers eventHeaders = new RecordHeaders();
+        eventMessageHeaders.forEach((key, value) -> eventHeaders.add(key, SerializationUtils.serialize(value)));
+        return eventHeaders;
+    }
+
+}