org.apache.pulsar.client.api

Interface MessageId

All Superinterfaces:

Comparable<MessageId>, Serializable

public interface MessageId
extends Comparable<MessageId>, 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 and 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.

Method Summary

Modifier and Type	Method and Description
static MessageId	fromByteArray(byte[] data) De-serialize a message id from a byte array.
static MessageId	fromByteArrayWithTopic(byte[] data, String topicName) De-serialize a message id from a byte array with its topic information attached.
byte[]	toByteArray() Serialize the message ID into a byte array.

Methods inherited from interface java.lang.Comparable

compareTo

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 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:

IOException - if the de-serialization fails

fromByteArrayWithTopic

static MessageId fromByteArrayWithTopic(byte[] data,
                                        String topicName)
                                 throws 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:

IOException - if the de-serialization fails