How to get message by key in Pulsar

Question

My situation is that I have compacted topic in Pulsar ( https://pulsar.apache.org/docs/en/concepts-topic-compaction/ ). With producer I am sending messages with key. Is it possible to get a specific message by using key with consumer?

My code:

Producer<byte[]> producer = client.newProducer()
            .topic(TOPIC_NAME)
            .compressionType(CompressionType.LZ4).create();

    String name = "name";
    String lastName = "lastname";

    byte[] nameBytes = name.getBytes();
    byte[] lastNameBytes = lastName.getBytes();

    producer.newMessage().key("key1").value(nameBytes).send();
    producer.newMessage().key("key2").value(lastNameBytes).send();

    Consumer<byte[]> consumer = client.newConsumer()
            .topic(TOPIC_NAME)
            .readCompacted(true)
            .subscriptionName("test")
            .subscribe();

    // need to get message by key

Answer 1

Pulsar SQL can be used to query data directly using Presto.

Alternatively you can use Bookkeeper Table API which is low level and should be avoided without a strong justification