Java KafkaConsumer.seekToBeginning方法代碼示例

import org.apache.kafka.clients.consumer.KafkaConsumer; //導入方法依賴的package包/類
private static void resetToLastCommittedPositions(KafkaConsumer<String, String> consumer) {
    for (TopicPartition topicPartition : consumer.assignment()) {
        OffsetAndMetadata offsetAndMetadata = consumer.committed(topicPartition);
        if (offsetAndMetadata != null)
            consumer.seek(topicPartition, offsetAndMetadata.offset());
        else
            consumer.seekToBeginning(singleton(topicPartition));
    }
}
 

import org.apache.kafka.clients.consumer.KafkaConsumer; //導入方法依賴的package包/類
/**
 * This will consume all records from only the partitions given.
 * @param topic Topic to consume from.
 * @param partitionIds Collection of PartitionIds to consume.
 * @return List of ConsumerRecords consumed.
 */
public List<ConsumerRecord<byte[], byte[]>> consumeAllRecordsFromTopic(final String topic, Collection<Integer> partitionIds) {
    // Create topic Partitions
    List<TopicPartition> topicPartitions = new ArrayList<>();
    for (Integer partitionId: partitionIds) {
        topicPartitions.add(new TopicPartition(topic, partitionId));
    }

    // Connect Consumer
    KafkaConsumer<byte[], byte[]> kafkaConsumer =
        kafkaTestServer.getKafkaConsumer(ByteArrayDeserializer.class, ByteArrayDeserializer.class);

    // Assign topic partitions & seek to head of them
    kafkaConsumer.assign(topicPartitions);
    kafkaConsumer.seekToBeginning(topicPartitions);

    // Pull records from kafka, keep polling until we get nothing back
    final List<ConsumerRecord<byte[], byte[]>> allRecords = new ArrayList<>();
    ConsumerRecords<byte[], byte[]> records;
    do {
        // Grab records from kafka
        records = kafkaConsumer.poll(2000L);
        logger.info("Found {} records in kafka", records.count());

        // Add to our array list
        records.forEach(allRecords::add);

    }
    while (!records.isEmpty());

    // close consumer
    kafkaConsumer.close();

    // return all records
    return allRecords;
}
 

import org.apache.kafka.clients.consumer.KafkaConsumer; //導入方法依賴的package包/類
private void maybeSeekToBeginning(final KafkaConsumer<byte[], byte[]> client,
                                  final Set<TopicPartition> inputTopicPartitions) {

    final List<String> inputTopics = options.valuesOf(inputTopicsOption);
    final String groupId = options.valueOf(applicationIdOption);

    if (inputTopicPartitions.size() > 0) {
        if (!dryRun) {
            client.seekToBeginning(inputTopicPartitions);
        } else {
            System.out.println("Following input topics offsets will be reset to beginning (for consumer group " + groupId + ")");
            for (final String topic : inputTopics) {
                if (allTopics.contains(topic)) {
                    System.out.println("Topic: " + topic);
                }
            }
        }
    }
}
 

import org.apache.kafka.clients.consumer.KafkaConsumer; //導入方法依賴的package包/類
public KafkaSource () throws IOException, PropertyException  {
    Properties configs = ConfUtils.getProps(CONFIG_PROPERTIES);
    statTopic = configs.getProperty(Constants.STATISTIC_TOPIC);
    if (statTopic == null) {
        throw new PropertyException("配置參數文件內容不能為空！ " + Constants.STATISTIC_TOPIC);
    }

    statTopicPartition = new TopicPartition(statTopic, 0);

    Properties statProps = ConfUtils.getProps(CONSUMER_PROPERTIES);
    statProps.setProperty("enable.auto.commit", "false");
    List<TopicPartition> topics = Arrays.asList(statTopicPartition);
    consumer = new KafkaConsumer(statProps);
    consumer.assign(topics);

    long beforeOffset = consumer.position(statTopicPartition);
    String offset = configs.getProperty("kafka.offset");
    if (offset.equalsIgnoreCase("none")) {
        ; // do nothing
    } else if  (offset.equalsIgnoreCase("begin")) {
        consumer.seekToBeginning(Lists.newArrayList(statTopicPartition));
    } else if (offset.equalsIgnoreCase("end")) {
        consumer.seekToEnd(Lists.newArrayList(statTopicPartition));
    } else {
        long nOffset = Long.parseLong(offset);
        consumer.seek(statTopicPartition, nOffset);
    }
    long afferOffset = consumer.position(statTopicPartition);
    LOG.info(String.format("init kafkaSoure OK. beforeOffset %d, afferOffset=%d", beforeOffset, afferOffset));
}
 

import org.apache.kafka.clients.consumer.KafkaConsumer; //導入方法依賴的package包/類
/**
 * Test that KafkaServer works as expected!
 *
 * This also serves as a decent example of how to use the producer and consumer.
 */
@Test
public void testProducerAndConsumer() throws Exception {
    final int partitionId = 0;

    // Define our message
    final String expectedKey = "my-key";
    final String expectedValue = "my test message";

    // Define the record we want to produce
    ProducerRecord<String, String> producerRecord = new ProducerRecord<>(topicName, partitionId, expectedKey, expectedValue);

    // Create a new producer
    KafkaProducer<String, String> producer = getKafkaTestServer().getKafkaProducer(StringSerializer.class, StringSerializer.class);

    // Produce it & wait for it to complete.
    Future<RecordMetadata> future = producer.send(producerRecord);
    producer.flush();
    while (!future.isDone()) {
        Thread.sleep(500L);
    }
    logger.info("Produce completed");

    // Close producer!
    producer.close();

    KafkaConsumer<String, String> kafkaConsumer =
        getKafkaTestServer().getKafkaConsumer(StringDeserializer.class, StringDeserializer.class);

    final List<TopicPartition> topicPartitionList = Lists.newArrayList();
    for (final PartitionInfo partitionInfo: kafkaConsumer.partitionsFor(topicName)) {
        topicPartitionList.add(new TopicPartition(partitionInfo.topic(), partitionInfo.partition()));
    }
    kafkaConsumer.assign(topicPartitionList);
    kafkaConsumer.seekToBeginning(topicPartitionList);

    // Pull records from kafka, keep polling until we get nothing back
    ConsumerRecords<String, String> records;
    do {
        records = kafkaConsumer.poll(2000L);
        logger.info("Found {} records in kafka", records.count());
        for (ConsumerRecord<String, String> record: records) {
            // Validate
            assertEquals("Key matches expected", expectedKey, record.key());
            assertEquals("value matches expected", expectedValue, record.value());
        }
    }
    while (!records.isEmpty());

    // close consumer
    kafkaConsumer.close();
}
 

import org.apache.kafka.clients.consumer.KafkaConsumer; //導入方法依賴的package包/類
public void consume(String topic) throws Exception {
    if (maybeSetupPhase(topic, "simple-benchmark-consumer-load", true)) {
        return;
    }

    Properties props = setProduceConsumeProperties("simple-benchmark-consumer");

    KafkaConsumer<Integer, byte[]> consumer = new KafkaConsumer<>(props);

    List<TopicPartition> partitions = getAllPartitions(consumer, topic);
    consumer.assign(partitions);
    consumer.seekToBeginning(partitions);

    Integer key = null;

    long startTime = System.currentTimeMillis();

    while (true) {
        ConsumerRecords<Integer, byte[]> records = consumer.poll(POLL_MS);
        if (records.isEmpty()) {
            if (processedRecords == numRecords)
                break;
        } else {
            for (ConsumerRecord<Integer, byte[]> record : records) {
                processedRecords++;
                processedBytes += record.value().length + Integer.SIZE;
                Integer recKey = record.key();
                if (key == null || key < recKey)
                    key = recKey;
                if (processedRecords == numRecords)
                    break;
            }
        }
        if (processedRecords == numRecords)
            break;
    }

    long endTime = System.currentTimeMillis();

    consumer.close();
    printResults("Consumer Performance [records/latency/rec-sec/MB-sec read]: ", endTime - startTime);
}