Package org.apache.pulsar.client.api

Interface MessageId

  • All Superinterfaces:
    java.lang.Comparable<MessageId>, java.io.Serializable
    @Public
@Stable
public interface MessageId
extends java.lang.Comparable<MessageId>, java.io.Serializable
    Opaque unique identifier of a single message

    The MessageId can be used to reference a specific message, for example when acknowledging, without having to retain the message content in memory for an extended period of time.

    Message ids are Comparable and a bigger message id will imply that a message was published "after" the other one.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static MessageId earliest
      MessageId that represents the oldest message available in the topic.
      static MessageId latest
      MessageId that represents the next message published in the topic.

    • Field Detail

      • earliest

        static final MessageId earliest
        MessageId that represents the oldest message available in the topic.

      • latest

        static final MessageId latest
        MessageId that represents the next message published in the topic.

    • Method Detail

      • toByteArray

        byte[] toByteArray()
        Serialize the message ID into a byte array.

        The serialized message id can be stored away and later get deserialized by using fromByteArray(byte[]).

      • fromByteArray

        static MessageId fromByteArray​(byte[] data)
                        throws java.io.IOException
        De-serialize a message id from a byte array.
        Parameters:
        data - byte array containing the serialized message id
        Returns:
        the de-serialized messageId object
        Throws:
        java.io.IOException - if the de-serialization fails

      • fromByteArrayWithTopic

        static MessageId fromByteArrayWithTopic​(byte[] data,
                                        java.lang.String topicName)
                                 throws java.io.IOException
        De-serialize a message id from a byte array with its topic information attached.

        The topic information is needed when acknowledging a MessageId on a consumer that is consuming from multiple topics.

        Parameters:
        data - the byte array with the serialized message id
        topicName - the topic name
        Returns:
        a instance
        Throws:
        java.io.IOException - if the de-serialization fails