| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| package org.apache.atlas.kafka; |
| |
| import kafka.consumer.ConsumerIterator; |
| import kafka.consumer.KafkaStream; |
| import kafka.message.MessageAndMetadata; |
| import org.apache.atlas.notification.AbstractNotificationConsumer; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Kafka specific notification consumer. |
| * |
| * @param <T> the notification type returned by this consumer |
| */ |
| public class KafkaConsumer<T> extends AbstractNotificationConsumer<T> { |
| private static final Logger LOG = LoggerFactory.getLogger(KafkaConsumer.class); |
| |
| private final int consumerId; |
| private final ConsumerIterator iterator; |
| |
| |
| // ----- Constructors ---------------------------------------------------- |
| |
| /** |
| * Create a Kafka consumer. |
| * |
| * @param type the notification type returned by this consumer |
| * @param stream the underlying Kafka stream |
| * @param consumerId an id value for this consumer |
| */ |
| public KafkaConsumer(Class<T> type, KafkaStream<String, String> stream, int consumerId) { |
| super(type); |
| this.iterator = stream.iterator(); |
| this.consumerId = consumerId; |
| } |
| |
| |
| // ----- Iterator -------------------------------------------------------- |
| |
| @Override |
| public boolean hasNext() { |
| return iterator.hasNext(); |
| } |
| |
| |
| // ----- AbstractNotificationConsumer ------------------------------------ |
| |
| @Override |
| public String getNext() { |
| MessageAndMetadata message = iterator.next(); |
| LOG.debug("Read message: conumerId: {}, topic - {}, partition - {}, offset - {}, message - {}", |
| consumerId, message.topic(), message.partition(), message.offset(), message.message()); |
| return (String) message.message(); |
| } |
| } |