SimpleConsumerFactory.java

/*
 * Copyright 2015 Confluent Inc.
 *
 * 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.
 **/

package io.confluent.kafkarest;

import kafka.javaapi.consumer.SimpleConsumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.atomic.AtomicInteger;

public class SimpleConsumerFactory {

  private static final Logger log = LoggerFactory.getLogger(SimpleConsumerManager.class);

  private final KafkaRestConfig config;

  private final SimpleConsumerConfig simpleConsumerConfig;
  private final AtomicInteger clientIdCounter;

  public SimpleConsumerFactory(final KafkaRestConfig config) {
    this.config = config;

    clientIdCounter = new AtomicInteger(0);
    simpleConsumerConfig = new SimpleConsumerConfig(config.getOriginalProperties());
  }

  public SimpleConsumerConfig getSimpleConsumerConfig() {
    return simpleConsumerConfig;
  }

  // The factory *must* return a SimpleConsumer with a unique clientId, as the clientId is
  // used by the SimpleConsumerPool to uniquely identify the consumer
  private String nextClientId() {

    final StringBuilder id = new StringBuilder();
    id.append("rest-simpleconsumer-");

    final String serverId = this.config.getString(KafkaRestConfig.ID_CONFIG);
    if (!serverId.isEmpty()) {
      id.append(serverId);
      id.append("-");
    }

    id.append(Integer.toString(clientIdCounter.incrementAndGet()));

    return id.toString();
  }

  public SimpleConsumer createConsumer(final String host, final int port) {

    final String clientId = nextClientId();

    log.debug("Creating SimpleConsumer with id {} (host:{}, port:{})", clientId, host, + port);
    return new SimpleConsumer(
        host, port,
        simpleConsumerConfig.socketTimeoutMs(),
        simpleConsumerConfig.socketReceiveBufferBytes(),
        clientId);
  }

}