org.apache.pulsar.client.api

接口 MessageId

所有超级接口:

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.

字段概要

字段

限定符和类型	字段和说明
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.

方法概要

限定符和类型	方法和说明
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.

从接口继承的方法 java.lang.Comparable

compareTo

字段详细资料

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.

方法详细资料

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.

参数:

data - byte array containing the serialized message id

返回:

the de-serialized messageId object

抛出:

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.

参数:

data - the byte array with the serialized message id

topicName - the topic name

返回:

a instance

抛出:

IOException - if the de-serialization fails