java - 如何获取kafka偏移量数据，在时间戳上指定

Question

当我尝试运行它时，我尝试根据时间戳从 Kafka 主题获取偏移量，但抛出空指针错误，

Map<TopicPartition, Long> timestampsToSearch = new HashMap<>();
              for (TopicPartition partition : partitions) {
                timestampsToSearch.put(partition,  startTimestamp);
              }
Map<TopicPartition, OffsetAndTimestamp> outOffsets = consumer.offsetsForTimes(timestampsToSearch);
              for (TopicPartition partition : partitions) {
                Long seekOffset = outOffsets.get(partition).offset();
consumer.seek(partition, seekOffset);

任何帮助将不胜感激。

Answer 1

要查找与时间戳相对应的偏移量，您需要使用 offsetsForTimes()方法。

例如，这将打印 mytopic 的分区 0 对应于 1 秒前的偏移量:

try (KafkaConsumer<String, String> consumer = new KafkaConsumer<>(configs);) {
    Map<TopicPartition, Long> timestamps = new HashMap<>();
    timestamps.put(new TopicPartition("mytopic", 0), System.currentTimeMillis()-1*1000);
    Map<TopicPartition, OffsetAndTimestamp> offsets = consumer.offsetsForTimes(timestamps);
    System.err.println(offsets);
}

这将显示如下内容:

{offset-test-0=(timestamp=1561469319192, leaderEpoch=0, offset=100131)}