生产者与消费者的Java实现

首先创建maven工程，需要引入的包：

<dependencies>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-clients</artifactId>
        <version>0.10.2.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka_2.10</artifactId>
        <version>0.10.2.1</version>
    </dependency>
</dependencies>

然后就可以实现生产者与消费者，在创建topic时，如果需要删除已经存在的topic，则需要配置delete.topic.enable=true，否则无法删除对应的topic。

/**
 消费者
**/
public class KafkaConsumerDemo
{
    private  final KafkaConsumer<String, String> consumer;

    private KafkaConsumerDemo(){
        Properties props = new Properties();
        props.put("bootstrap.servers", "10.xxx.xxx.149:9092, 10.xxx.xxx.182:9092, 10:xxx.xxx.190:9092");
        props.put("group.id", "test");
        props.put("enable.auto.commit", "true");
        props.put("auto.commit.interval.ms", "");
        props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        consumer = new KafkaConsumer<String, String>(props);
    }

    void consume(){
        consumer.subscribe(Arrays.asList(KafkaProducerDemo.TOPIC));
        while (true) {
            ConsumerRecords<String, String> records = consumer.poll();
            for (ConsumerRecord<String, String> record : records)
                System.out.printf("offset = %d, key = %s, value = %s%n", record.offset(), record.key(), record.value());
        }
    }

    public  static  void main(String[] args){
        new KafkaConsumerDemo().consume();
    }
}

/**
 * 生成者
 *
 */
public class KafkaProducerDemo
{
    private final Producer<String, String> kafkaProducer;

    public final static String TOPIC = "JAVA_TOPIC";

    private KafkaProducerDemo()
    {
        kafkaProducer = createKafkaProducer();
    }

    private Producer<String, String> createKafkaProducer()
    {
        Properties props = new Properties();
        props.put("bootstrap.servers", "10.185.156.149:9092, 10.185.156.182:9092, 10:185.156.190:9092");
        props.put("acks", "all");
        props.put("retries", 0);
        props.put("batch.size", 16384);
        props.put("linger.ms", 1);
        props.put("buffer.memory", 33554432);
        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        Producer<String, String> kafkaProducer = new KafkaProducer<String, String>(props);
        return kafkaProducer;
    }

    void produce()
    {
        for (int i = 1; i < 1000; i++)
        {
            try
            {
                Thread.sleep(1000);
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
            String key = String.valueOf("key" + i);
            String data = "hello kafka message:" + key;
            kafkaProducer.send(new ProducerRecord<>(TOPIC, key, data), new Callback()
            {
                @Override
                public void onCompletion(RecordMetadata recordMetadata, Exception e)
                {
                    // do sth
                }
            });
            System.out.println(data);
        }
    }

    public static void main(String[] args)
    {
        KafkaCreateTopic.createTopic("JAVA_TOPIC", 3, 1);
        new KafkaProducerDemo().produce();
    }
}

/**
  创建topic
**/
public class KafkaCreateTopic
{

    public static void createTopic(String topic, int partitions, int replicationFactor)
    {
        ZkUtils zkUtils = ZkUtils.apply("10.xxx.xxx.149:2181", 30000, 30000, JaasUtils.isZkSecurityEnabled());
        if (AdminUtils.topicExists(zkUtils, topic))
        {
            deleteTopic(zkUtils, topic);
        }
        AdminUtils.createTopic(zkUtils, topic, partitions, replicationFactor, new Properties(),
                RackAwareMode.Enforced$.MODULE$);
        zkUtils.close();
    }

    public static void deleteTopic(ZkUtils zkUtils, String topic)
    {
        AdminUtils.deleteTopic(zkUtils, topic);
        System.out.println("delete the topic " + topic);

    }
}