com.google.cloud.pubsub

Class Topic

java.lang.Object

com.google.cloud.pubsub.TopicInfo

com.google.cloud.pubsub.Topic

All Implemented Interfaces:

Serializable

public class Topic
extends TopicInfo

A Google Cloud Pub/Sub topic. A topic is a named resource to which messages are sent by publishers. Subscribers can receive messages sent to a topic by creating subscriptions. Topic adds a layer of service-related functionality over TopicInfo. Objects of this class are immutable. To get a Topic object with the most recent information use reload() or reloadAsync().

See Also:

Pub/Sub Data Model, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Topic.Builder A builder for Topic objects.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	delete() Deletes this topic.
Future<Boolean>	deleteAsync() Sends a request for deleting this topic.
boolean	equals(Object obj)
int	hashCode()
Page<SubscriptionId>	listSubscriptions(PubSub.ListOption... options) Lists the identities of the subscriptions for this topic.
Future<AsyncPage<SubscriptionId>>	listSubscriptionsAsync(PubSub.ListOption... options) Sends a request for listing the identities of subscriptions for this topic.
List<String>	publish(Iterable<Message> messages) Publishes a number of messages to this topic.
String	publish(Message message) Publishes a message to this topic.
List<String>	publish(Message message, Message... messages) Publishes a number of messages to this topic.
Future<List<String>>	publishAsync(Iterable<Message> messages) Sends a request to publish a number of messages to this topic.
Future<String>	publishAsync(Message message) Sends a request for publishing a message to the this topic.
Future<List<String>>	publishAsync(Message message, Message... messages) Sends a request to publish a number of messages to this topic.
PubSub	pubSub() Returns the topic's PubSub object used to issue requests.
Topic	reload() Fetches current topic's latest information.
Future<Topic>	reloadAsync() Sends a request to fetch current topic's latest information.
Topic.Builder	toBuilder() Returns a builder for the topic object.

Methods inherited from class com.google.cloud.pubsub.TopicInfo

builder, name, of, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

toBuilder

public Topic.Builder toBuilder()

Description copied from class: TopicInfo

Returns a builder for the topic object.

Overrides:

toBuilder in class TopicInfo

hashCode

public final int hashCode()

Overrides:

hashCode in class TopicInfo

equals

public final boolean equals(Object obj)

Overrides:

equals in class TopicInfo

pubSub

public PubSub pubSub()

Returns the topic's PubSub object used to issue requests.

delete

public boolean delete()

Deletes this topic.

Returns:

true if the topic was deleted, false if it was not found

Throws:

PubSubException - upon failure

deleteAsync

public Future<Boolean> deleteAsync()

Sends a request for deleting this topic. This method returns a Future object to consume the result. Future.get() returns true if the topic was deleted, false if it was not found.

Throws:

PubSubException - upon failure

reload

public Topic reload()

Fetches current topic's latest information. Returns null if the topic does not exist.

Returns:

a Topic object with latest information or null if not found

Throws:

PubSubException - upon failure

reloadAsync

public Future<Topic> reloadAsync()

Sends a request to fetch current topic's latest information. This method returns a Future object to consume the result. Future.get() returns a Topic object with latest information or null if not found.

Throws:

PubSubException - upon failure

publish

public String publish(Message message)

Publishes a message to this topic. This method returns a service-generated id for the published message. Service-generated ids are guaranteed to be unique within the topic.

Parameters:

message - the message to publish

Returns:

a unique service-generated id for the message

Throws:

PubSubException - upon failure, if the topic does not exist or if the message has empty payload and no attributes

publishAsync

public Future<String> publishAsync(Message message)

Sends a request for publishing a message to the this topic. This method returns a Future object to consume the result. Future.get() returns a service-generated id for the published message. Service-generated ids are guaranteed to be unique within the topic.

Parameters:

message - the message to publish

Returns:

a Future for the unique service-generated id for the message

publish

public List<String> publish(Message message,
                   Message... messages)

Publishes a number of messages to this topic. This method returns a list of service-generated ids for the published messages. Service-generated ids are guaranteed to be unique within the topic.

Parameters:

message - the first message to publish

messages - other messages to publish

Returns:

a list of unique, service-generated, ids. Ids are in the same order as the messages.

Throws:

PubSubException - upon failure, if the topic does not exist or if one of the messages has empty payload and no attributes

publishAsync

public Future<List<String>> publishAsync(Message message,
                                Message... messages)

Sends a request to publish a number of messages to this topic. This method returns a Future object to consume the result. Future.get() returns a list of service-generated ids for the published messages. Service-generated ids are guaranteed to be unique within the topic.

Parameters:

message - the first message to publish

messages - other messages to publish

Returns:

a Future for the unique, service-generated ids. Ids are in the same order as the messages.

publish

public List<String> publish(Iterable<Message> messages)

Publishes a number of messages to this topic. This method returns a list ofservice-generated ids for the published messages. Service-generated ids are guaranteed to be unique within the topic.

Parameters:

messages - the messages to publish

Returns:

a list of unique, service-generated, ids. Ids are in the same order as the messages.

Throws:

PubSubException - upon failure, if the topic does not exist or if one of the messages has empty payload and no attributes

publishAsync

public Future<List<String>> publishAsync(Iterable<Message> messages)

Sends a request to publish a number of messages to this topic. This method returns a Future object to consume the result. Future.get() returns a list of service-generated ids for the published messages. Service-generated ids are guaranteed to be unique within the topic.

Parameters:

messages - the messages to publish

Returns:

a Future for the unique, service-generated ids. Ids are in the same order as the messages.

listSubscriptions

public Page<SubscriptionId> listSubscriptions(PubSub.ListOption... options)

Lists the identities of the subscriptions for this topic. This method returns a Page object that can be used to consume paginated results. Use PubSub.ListOption to specify the page size or the page token from which to start listing subscriptions.

Throws:

PubSubException - upon failure

listSubscriptionsAsync

public Future<AsyncPage<SubscriptionId>> listSubscriptionsAsync(PubSub.ListOption... options)

Sends a request for listing the identities of subscriptions for this topic. This method returns a Future object to consume the result. Future.get() returns an AsyncPage object that can be used to asynchronously handle paginated results. Use PubSub.ListOption to specify the page size or the page token from which to start listing subscriptions.