Publish/Subscribe API for Java SDK

Breaking changes in v9.0.0

PubNub Kotlin SDK version 9.0.0 unifies the codebases for Kotlin and Java SDKs, introduces a new way of instantiating the PubNub client, and changes asynchronous API callbacks and emitted status events. These changes can impact applications built with previous versions (< 9.0.0 ) of the Kotlin SDK.

For more details about what has changed, refer to Java/Kotlin SDK migration guide.

The foundation of PubNub is the ability to send and deliver a message in less than 30ms. Send a message to just one other person, or broadcast to thousands of subscribers at once.

For higher-level conceptual details on publishing and subscribing, refer to Connection Management and to Publish Messages.

Publish​

icon

Available in entities

Channel

publish() sends a message to all channel subscribers. A successfully published message is replicated across PubNub's points of presence and sent simultaneously to all subscribed clients on a channel.

  • You must initialize PubNub with the publishKey.
  • You must create a Channel entity where you will publish to.
  • You don't have to be subscribed to a channel to publish to it.
  • You cannot publish to multiple channels simultaneously.

Method(s)​

To publish to a channel, you must first create a Channel entity where you provide the name of the channel you want to publish to.

Channel channel = pubnub.channel("myChannel");

channel.publish(Object message)
    .shouldStore(Boolean)
    .meta(Object)
    .queryParam(HashMap)
    .usePOST(Boolean)
    .ttl(Integer);
    .customMessageType(String)
* required
ParameterDescription
message *
Type: Object
Default:
n/a
The payload.
shouldStore
Type: Boolean
Default:
account default
Store in history.
If shouldStore is not specified, then the history configuration on the key is used.
meta
Type: Object
Default:
Not set
Meta data object which can be used with the filtering ability.
queryParam
Type: HashMap<string,string>
Default:
Not set
One or more query parameters to be passed to the server, for analytics purposes. Overridden in case of conflicts with reserved PubNub parameters, such as uuid or instance_id. Accessible from your PubNub Dashboard, and never returned in server responses.
usePOST
Type: Boolean
Default:
false
Use POST to publish.
ttl
Type: Integer
Default:
n/a
Set a per message time to live in Message Persistence.
  1. If shouldStore = true, and ttl = 0, the message is stored with no expiry time.
  2. If shouldStore = true and ttl = X (X is an Integer value), the message is stored with an expiry time of X hours unless you have message retention set to Unlimited on your keyset configuration in the Admin Portal.
  3. If shouldStore = false, the ttl parameter is ignored.
  4. If ttl is not specified, then expiration of the message defaults back to the expiry value for the key.
customMessageType
Type: String
Default:
n/a
A case-sensitive, alphanumeric string from 3 to 50 characters describing the business-specific label or category of the message. Dashes - and underscores _ are allowed. The value cannot start with special characters or the string pn_ or pn-.

Examples: text, action, poll.
sync
Type: Command
Default:
n/a
Block the thread, exception thrown if something goes wrong.
async
Type: Consumer<Result>
Default:
n/a
Consumer of a Result of type PNPublishResult

Basic Usage​

Reference code

This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.

Publish a message to a channel​


Subscribe to the channel

Before running the above publish example, either using the Debug Console or in a separate script running in a separate terminal window, subscribe to the same channel that is being published to.

Other Examples​

Publish with metadata​


Publishing JsonObject (Google GSON)​


Publishing JsonArray (Google GSON)​


Publishing JSONObject (org.json)​


Publishing JSONArray (org.json)​


Store the published message for 10 hours​


Response​

The publish() operation returns a PNPublishResult:

MethodDescription
getTimetoken()
Type: Long
Returns a long representation of the timetoken when the signal was published.

Fire​

icon

Available in entities

Channel

The fire endpoint allows the client to send a message to Functions Event Handlers and Illuminate. These messages will go directly to any Event Handlers registered on the channel that you fire to and will trigger their execution. The content of the fired request will be available for processing within the Event Handler. The message sent via fire() isn't replicated, and so won't be received by any subscribers to the channel. The message is also not stored in history.

  • You must initialize PubNub with the publishKey.
  • You must create a Channel entity where you will fire to.
  • The message sent via fire() isn't replicated and won't be received by subscribers.
  • The message is not stored in history.

Method(s)​

Channel channel = pubnub.channel("myChannel");

channel.fire(Object message)
    .meta(Object)
    .usePOST(Boolean);
* required
ParameterDescription
message *
Type: Object
Default:
n/a
The payload.
meta
Type: Object
Default:
Not set
Meta data object which can be used with the filtering ability.
usePOST
Type: Boolean
Default:
false
Use POST to publish.
sync
Type: Command
Default:
n/a
Block the thread, exception thrown if something goes wrong.
async
Type: Consumer<Result>
Default:
n/a
Consumer of a Result of type PNPublishResult

Basic Usage​


Response​

The fire() operation returns a PNPublishResult:

MethodDescription
getTimetoken()
Type: Long
Returns a long representation of the timetoken when the signal was published.

Signal​

icon

Available in entities

Channel

The signal() function is used to send a signal to all subscribers of a channel.

  • You must initialize PubNub with the publishKey.
  • You must create a Channel entity where you will fire to.
  • The message payload size (without the URI or headers) is limited to 64 bytes. If you require a larger payload size, contact support.

Method(s)​

Channel channel = pubnub.channel("myChannel");

channel.signal(Object message)
    .customMessageType(String);
* required
ParameterDescription
message *
Type: Object
The payload which will be serialized and sent.
customMessageType
Type: String
A case-sensitive, alphanumeric string from 3 to 50 characters describing the business-specific label or category of the message. Dashes - and underscores _ are allowed. The value cannot start with special characters or the string pn_ or pn-.

Examples: text, action, poll.
sync
Type: PNPublishResult
Executes the call. Blocks the thread, exception is thrown if something goes wrong.
async
Type: Consumer<Result>
Executes the call asynchronously.

Basic Usage​


Response​

The signal() operation returns a PNPublishResult:

MethodDescription
getTimetoken()
Type: Long
Returns a long representation of the timetoken when the signal was published.

Subscribe​

The subscribe function creates an open TCP socket to PubNub and begins listening for messages and events on a specified entity or set of entities. To subscribe successfully, you must configure the appropriate subscribeKey at initialization.

Conceptual overview

For more general information about subscriptions, refer to Subscriptions.

Entities are first-class citizens that provide access to their encapsulated APIs. You can subscribe using the PubNub client object or directly on a specific entity:

A newly subscribed client receives messages after the subscribe() call completes. You can configure retryConfiguration to automatically attempt to reconnect if a client gets disconnected.

Subscription scope​

Subscription objects provide an interface to attach listeners for various real-time update types. Your app receives messages and events via those event listeners. Two types of subscriptions are available:

  • Subscription, created from an entity with a scope of only that entity (for example, a particular channel)
  • SubscriptionSet, created from the PubNub client with a global scope (for example, all subscriptions created on a single pubnub object ). A subscription set can have one or more subscriptions.

The event listener is a single point through which your app receives all the messages, signals, and events in the entities you subscribed to. For information on adding event listeners, refer to Event listeners.

Create a subscription​

Managing subscription lifecycle

The Subscription object implements the AutoCloseable interface to help you release resources by unsubscribing and removing all listeners. Always call Subscription.close() when you no longer need this Subscription.

An entity-level Subscription allows you to receive messages and events for only that entity for which it was created. Using multiple entity-level Subscriptions is useful for handling various message/event types differently in each channel.

// Entity-based, local-scoped

channel.subscription(SubscriptionOptions options)
* required
ParameterDescription
options
Type: SubscriptionOptions
Subscription behavior configuration. Use null for no specific options.

Basic usage​


Create a subscription set​

Managing subscription lifecycle

The SubscriptionSet object implements the AutoCloseable interface to help you release resources by unsubscribing and removing all listeners. Always call SubscriptionSet.close() when you no longer need this SubscriptionSet.

A client-level SubscriptionSet allows you to receive messages and events for all entities in the set. A single SubscriptionSet is useful for similarly handling various message/event types in each channel.

// client-based, general-scoped

pubnub.subscriptionSetOf(
    Set<String> channels, 
    Set<String> channelGroups, 
    SubscriptionOptions options
)
* required
ParameterDescription
 → channels
Type: Set<String>
Set of channel names to subscribe to. Use an empty set for no channels.
 → channelGroups
Type: Set<String>
Set of channel group names to subscribe to. Use an empty set for no channel groups.
 → options
Type: SubscriptionOptions
Additional subscription configuration to define the subscription behavior. If you don't set any options, EmptyOptions is used by default.
Add/remove sets

You can add and remove subscription sets to create new sets. Refer to the Other examples section for more information.

SubscriptionOptions​

SubscriptionOptions is a class designed to configure subscription behaviors with optional modifiers. When no specific options are required, EmptyOptions is set by default.

The class includes:

OptionDescription
receivePresenceEvents()
Whether presence updates for userIds should be delivered through the listener streams.

For more information on how to receive presence events and what those events are, refer to Presence Events.
filter(predicate: (PNEvent) -> Boolean)
Allows for custom filtering of events delivered to the subscription based on the provided predicate. Useful for event-specific handling.

Basic usage​


Method(s)​

Subscription and SubscriptionSet use the same methods to subscribe:

Subscribe​

To subscribe, you can use the following method:


Basic usage​

Other examples​
Create a subscription set and add/remove subscriptions​

Returns​

The subscribe() method doesn't have a return value.

Subscribe with timetoken​

Impact on other subscriptions

Subscribing with a timetoken affects all other subscriptions because it overwrites the timetoken in the single PubNub server connection in the SDK. However, those other subscriptions will not deliver messages older than ones that were already delivered - after receiving an event, a subscription only gets future events, ignoring those before or at the time of the last event received.

To subscribe to real-time updates from a given timetoken, use the following method:

subscriptionSet.subscribe(SubscriptionCursor(timetoken = yourTimeToken))
* required
ParameterDescription
cursor *
Type: SubscriptionCursor
Cursor from which to return any available cached messages. SubscriptionCursor would typically include a timetoken (long integer) representing the point in time from which to receive updates.
Basic usage​

Returns​

The method for subscribing with a timetoken doesn't have a return value.

Event listeners​

Messages and events are received in your app using a listener. This listener allows a single point to receive all messages, signals, and events.

You can attach listeners to the instances of Subscription, SubscriptionSet, and, in the case of the connection status, the PubNub client.

Add listeners​

You can add listeners for various types of updates related to your subscription. You can implement listeners for general updates (that handle multiple event types at once) or choose listeners dedicated to specific event types such as Message or File.

Handle multiple event types​

Method(s)​
fun addListener(listener: EventListener)
Basic usage​

Handle one event type​

Method(s)​

You can also directly register listeners for specific event types on the subscription object by assigning lambda expressions. This method allows you to handle events such as messages, signals, message actions, files, objects, and presence.

Using this method, you cannot have multiple listeners attached to the same event type. Assigning a new listener with this method overwrites the previous one.

Basic usage​

Remove event listener​

To remove the listener for a specific event, assign null to it.

subscription.setOnMessage(null);

Add connection status listener​

Use the StatusListener interface with your PubNub instance to add a listener dedicated to connection status updates.

Client scope

This listener is only available on the PubNub object.

Method(s)​

pubnub.addListener(object : StatusListener() {
    override fun status(pubnub: PubNub, status: PNStatus) {
        // Handle connection status updates
        println("Connection Status: ${status.category}")
    }
})

Basic usage​


Returns​

This method returns the subscription status and will emit various statuses depending on your client network connection.

To help you adjust your app code, see the Status Events for Subscribe for the exact mapping between the current and deprecated Kotlin SDK statuses.

For more generic information, head to SDK Connection Lifecycle.

Unsubscribe​

Stop receiving real-time updates from a Subscription or a SubscriptionSet.

Method(s)​


Basic Usage​


Returns​

None

Unsubscribe All​

Stop receiving real-time updates from all listeners and remove the entities associated with them.

Client scope

This method is only available on the PubNub object.

Method(s)​

pubnub.unsubscribeAll()

Basic Usage​


Returns​

None

Publish (old)​

Not recommended

The use of this method is discouraged. Use Publish instead.

The publish() function is used to send a message to all subscribers of a channel. To publish a message you must first specify a valid publishKey at initialization. A successfully published message is replicated across the PubNub Real-Time Network and sent simultaneously to all subscribed clients on a channel.

Messages in transit can be secured from potential eavesdroppers with SSL/TLS by setting ssl to true during initialization.

Publish Anytime​

It's not required to be subscribed to a channel in order to publish to that channel.

Message Data​

The message argument can contain any JSON serializable data, including: Objects, Arrays, Ints and Strings. data should not contain special Java classes or functions as these will not serialize. String content can include any single-byte or multi-byte UTF-8 character.

Don't JSON serialize

You should not JSON serialize the message and meta parameters when sending signals, messages, or files as the serialization is done automatically. Pass the full object as the message/meta payload and let PubNub take care of everything for you.

Message Size​

The maximum number of characters per message is 32 KiB by default. The maximum message size is based on the final escaped character count, including the channel name. An ideal message size is under 1800 bytes which allows a message to be compressed and sent using single IP datagram (1.5 KiB) providing optimal network performance.

If the message you publish exceeds the configured size, you will receive the following message:

Message Too Large Error​
["PUBLISHED",[0,"Message Too Large","13524237335750949"]]

For further details, check Calculating Message Payload Size Before Publish.

Message Publish Rate​

Messages can be published as fast as bandwidth conditions will allow. There is a soft limit based on max throughput since messages will be discarded if the subscriber can't keep pace with the publisher.

For example, if 200 messages are published simultaneously before a subscriber has had a chance to receive any messages, the subscriber may not receive the first 100 messages because the message queue has a limit of only 100 messages stored in memory.

Publishing to Multiple Channels​

It is not possible to publish a message to multiple channels simultaneously. The message must be published to one channel at a time.

Publishing Messages Reliably​

There are some best practices to ensure messages are delivered when publishing to a channel:

  • Publish to any given channel in a serial manner (not concurrently).
  • Check that the return code is success (for example, [1,"Sent","136074940..."])
  • Publish the next message only after receiving a success return code.
  • If a failure code is returned ([0,"blah","<timetoken>"]), retry the publish.
  • Avoid exceeding the in-memory queue's capacity of 100 messages. An overflow situation (aka missed messages) can occur if slow subscribers fail to keep up with the publish pace in a given period of time.
  • Throttle publish bursts in accordance with your app's latency needs, for example, Publish no faster than 5 msgs per second to any one channel.

Method(s)​

To Publish a message you can use the following method(s) in the Java SDK:

this.pubnub.publish()
    .message(Object)
    .channel(String)
    .shouldStore(Boolean)
    .meta(Object)
    .queryParam(HashMap)
    .usePOST(Boolean)
    .ttl(Integer);
* required
ParameterDescription
message *
Type: Object
Default:
n/a
The payload.
channel *
Type: String
Default:
n/a
Destination of the message (channel ID).
shouldStore
Type: Boolean
Default:
account default
Store in history.
If shouldStore is not specified, then the history configuration on the key is used.
meta
Type: Object
Default:
Not set
Meta data object which can be used with the filtering ability.
queryParam
Type: HashMap<string,string>
Default:
Not set
One or more query parameters to be passed to the server, for analytics purposes. Overridden in case of conflicts with reserved PubNub parameters, such as uuid or instance_id. Accessible from your PubNub Dashboard, and never returned in server responses.
usePOST
Type: Boolean
Default:
false
Use POST to publish.
ttl
Type: Integer
Default:
n/a
Set a per message time to live in Message Persistence.
  1. If shouldStore = true, and ttl = 0, the message is stored with no expiry time.
  2. If shouldStore = true and ttl = X (X is an Integer value), the message is stored with an expiry time of X hours unless you have message retention set to Unlimited on your keyset configuration in the Admin Portal.
  3. If shouldStore = false, the ttl parameter is ignored.
  4. If ttl is not specified, then expiration of the message defaults back to the expiry value for the key.
sync
Type: Command
Default:
n/a
Block the thread, exception thrown if something goes wrong.
async
Type: Consumer<Result>
Default:
n/a
Consumer of a Result of type PNPublishResult

Basic Usage​

Publish a message to a channel​

Subscribe to the channel

Before running the above publish example, either using the Debug Console or in a separate script running in a separate terminal window, subscribe to the same channel that is being published to.

Returns​

The publish() operation returns a PNPublishResult which contains the following operations:

MethodDescription
getTimetoken()
Type: Long
Returns a long representation of the timetoken when the message was published.

Other Examples​

Publish with metadata​

Publishing JsonObject (Google GSON)​

Publishing JsonArray (Google GSON)​

Publishing JSONObject (org.json)​

Publishing JSONArray (org.json)​

Store the published message for 10 hours​

Fire (old)​

Not recommended

The use of this method is discouraged. Use Fire instead.

The fire endpoint allows the client to send a message to Functions Event Handlers and Illuminate. These messages will go directly to any Event Handlers registered on the channel that you fire to and will trigger their execution. The content of the fired request will be available for processing within the Event Handler. The message sent via fire() isn't replicated, and so won't be received by any subscribers to the channel. The message is also not stored in history.

Method(s)​

To Fire a message you can use the following method(s) in the Java SDK:

this.pubnub.fire()
    .message(Object)
    .channel(String)
    .meta(Object)
    .usePOST(Boolean);
* required
ParameterDescription
message *
Type: Object
Default:
n/a
The payload.
channel *
Type: String
Default:
n/a
Destination of the message (channel ID).
meta
Type: Object
Default:
Not set
Meta data object which can be used with the filtering ability.
usePOST
Type: Boolean
Default:
false
Use POST to publish.
sync
Type: Command
Default:
n/a
Block the thread, exception thrown if something goes wrong.
async
Type: Consumer<Result>
Default:
n/a
Consumer of a Result of type PNPublishResult

Basic Usage​


Response​

The fire() operation returns a PNPublishResult:

MethodDescription
getTimetoken()
Type: Long
Returns a long representation of the timetoken when the signal was published.

Signal (old)​

Not recommended

The use of this method is discouraged. Use Signal instead.

The signal() function is used to send a signal to all subscribers of a channel.

By default, signals are limited to a message payload size of 64 bytes. This limit applies only to the payload, and not to the URI or headers. If you require a larger payload size, please contact support.

Method(s)​

To Signal a message you can use the following method(s) in the Java SDK:

this.pubnub.signal()
    .message(Object)
    .channel(String);
* required
ParameterDescription
message *
Type: Object
The payload which will be serialized and sent.
channel *
Type: String
The channel ID which the signal will be sent to.
sync
Type: PNPublishResult
Executes the call. Blocks the thread, exception is thrown if something goes wrong.
async
Type: Consumer<Result>
Executes the call asynchronously.

Basic Usage​


Response​

The signal() operation returns a PNPublishResult object which contains the following operations:

MethodDescription
getTimetoken()
Type: Long
Returns a long representation of the timetoken when the signal was published.

Subscribe (old)​

Not recommended

The use of this method is discouraged. Use Subscribe instead.

Receive messages​

Your app receives messages and events via event listeners. The event listener is a single point through which your app receives all the messages, signals, and events that are sent in any channel you are subscribed to.

For more information about adding a listener, refer to the Event Listeners for more details. Listeners should be added before calling the method.

Description​

This function causes the client to create an open TCP socket to the PubNub Real-Time Network and begin listening for messages on a specified channel ID. To subscribe to a channel ID the client must send the appropriate subscribeKey at initialization.

By default a newly subscribed client will only receive messages published to the channel after the subscribe() call completes. If a client gets disconnected from a channel, it can automatically attempt to reconnect to that channel ID and retrieve any available messages that were missed during that period. This can be achieved by setting setReconnectionPolicy to PNReconnectionPolicy.LINEAR, when initializing the client.

Unsubscribing from all channels

Unsubscribing from all channels, and then subscribing to a new channel Y is not the same as subscribing to channel Y and then unsubscribing from the previously-subscribed channel(s). Unsubscribing from all channels resets the last-received timetoken and thus, there could be some gaps in the subscription that may lead to message loss.

Method(s)​

To Subscribe to a channel you can use the following method(s) in the Java SDK:

pubnub.subscribe()
    .channels(Array)
    .channelGroups(Arrays)
    .withTimetoken(Long)
    .withPresence()
    .execute();
* required
ParameterDescription
channels
Type: Array
Subscribe to channels, Either channel ID or channelGroup is required
channelGroups
Type: Array
Subscribe to channel groups, Either channel ID or channelGroup is required
withTimetoken
Type: Long
Pass a timetoken
withPresence()
Type: Command
Also subscribe to related presence information
execute() *
Type: Command
Command that will execute subscribe.

Basic Usage​

Subscribe to a channel:

pubnub.subscribe()
    .channels(Arrays.asList("my_channel")) // subscribe to channels
    .execute();
Event listeners

The response of the call is handled by adding a Listener. Please see the Listeners section.

Returns​

PNMessageResult

PNMessageResult is returned in the Listeners.

The subscribe() operation returns a PNStatus which contains the following operations:

MethodDescription
getCategory()
Type: Enum of type PNStatusCategory.
Details of PNStatusCategory are here
isError()
Type: Boolean
Is true in case of an error.

The subscribe() operation returns a PNMessageResult for messages which contains the following operations:

MethodDescription
getMessage()
Type: JsonElement
The message sent on the channel ID.
getSubscription()
Type: String
The channel group or wildcard subscription match (if exists).
getChannel()
Type: String
The channel ID for which the message belongs.
getTimetoken()
Type: Long
Timetoken for the message.
getUserMetadata()
Type: Object
User metadata.

The subscribe() operation returns a PNPresenceEventResult from presence which contains the following operations:

MethodDescription
getEvent()
Type: String
Events like join, leave, timeout, state-change, interval.
getUuid()
Type: String
UUID for the event.
getTimestamp()
Type: Long
Timestamp for the event.
getOccupancy()
Type: Int
Current occupancy.
getState()
Type: JsonElement
State of the UUID.
getSubscription()
Type: String
The channel group or wildcard subscription match (if exists).
getChannel()
Type: String
The channel ID for which the message belongs.
getTimetoken()
Type: Long
Timetoken of the message.
getUserMetadata()
Type: Object
User metadata.

The subscribe() operation returns a PNSignalResult for signals which contains the following operations:

MethodDescription
getMessage()
Type: JsonElement
The signal sent on the channel ID.
getSubscription()
Type: String
The channel group or wildcard subscription match (if exists).
getChannel()
Type: String
The channel ID for which the signal belongs.
getTimetoken()
Type: Long
Timetoken for the signal.
getUserMetadata()
Type: Object
User metadata.

Other Examples​

Basic subscribe with logging​

Subscribing to multiple channels​

It's possible to subscribe to more than one channel using the Multiplexing feature. The example shows how to do that using an array to specify the channel names.

Alternative subscription methods

You can also use Wildcard Subscribe and Channel Groups to subscribe to multiple channels at a time. To use these features, the Stream Controller add-on must be enabled on your keyset in the Admin Portal.

pubnub.subscribe()
    .channels(Arrays.asList("my_channel1","my_channel2" ))
    .execute();
Subscribing to a Presence channel​
Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

For any given channel there is an associated Presence channel. You can subscribe directly to the channel by appending -pnpres to the channel name. For example the channel named my_channel would have the presence channel named my_channel-pnpres. Presence data can be observed inside the SubscribeCallback#message(PubNub, PNMessageResult) callback.


Sample Responses​
Join Event​

Leave Event​

Timeout Event​

Custom Presence Event (State Change)​

Interval Event​

When a channel is in interval mode with presence_deltas pnconfig flag enabled, the interval message may also include the following fields which contain an array of changed UUIDs since the last interval message. This settings can be altered in the Admin Portal

  • joined
  • left
  • timedout

For example, this interval message indicates there were 2 new UUIDs that joined and 1 timed out UUID since the last interval:

if (presence.getEvent().equals("interval")) {
    presence.getTimestamp(); // <unix timestamp>
    presence.getOccupancy(); // <# users in channel>
    presence.getJoin(); // ["uuid1", "uuid2"]
    presence.getTimeout(); // ["uuid3"]
}

If the full interval message is greater than 30KB (since the max publish payload is ∼32KB), none of the extra fields will be present. Instead there will be a here_now_refresh boolean field set to true. This indicates to the user that they should do a hereNow request to get the complete list of users present in the channel.

if (presence.getEvent().equals("interval")) {
    presence.getTimestamp(); // <unix timestamp>
    presence.getOccupancy(); // <# users in channel>
    presence.getHereNowRefresh() // true
}
Wildcard subscribe to channels​
Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal (with Enable Wildcard Subscribe checked). Read the support page on enabling add-on features on your keys.

Wildcard subscribes allow the client to subscribe to multiple channels using wildcard. For example, if you subscribe to a.* you will get all messages for a.b, a.c, a.x. The wildcarded * portion refers to any portion of the channel string name after the dot (.).

pubnub.subscribe()
    .channels(Arrays.asList("foo.*"))
    .execute();
Wildcard grants and revokes

Only one level (a.*) of wildcarding is supported. If you grant on * or a.b.*, the grant will treat * or a.b.* as a single channel named either * or a.b.*. You can also revoke permissions from multiple channels using wildcards but only if you previously granted permissions using the same wildcards. Wildcard revokes, similarly to grants, only work one level deep, like a.*.

Subscribing with State​
Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

Required UUID

Always set the UUID to uniquely identify the user or device that connects to PubNub. This UUID should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UUID, you won't be able to connect to PubNub.


Subscribe to a channel group​
Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.


Subscribe to the presence channel of a channel group​
Requires Stream Controller and Presence add-ons

This method requires both the Stream Controller and Presence add-ons are enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.


Unsubscribe (old)​

Not recommended

The use of this method is discouraged. Use Unsubscribe instead.

Description​

This function causes the client to remove an open TCP socket to the PubNub Real-Time Network and stop listening for messages on a specified channel ID.

Method(s)​

To Unsubscribe from a channel you can use the following method(s) in the Java SDK:

pubnub.unsubscribe()
    .channels(Array)
    .channelGroups(Arrays)
    .execute();
* required
ParameterDescription
channels
Type: Array
Unsubscribe from channels, Either channel ID or channelGroup is required
channelGroups
Type: Array
Unsubscribe from channel groups, Either channel ID or channelGroup is required
execute() *
Type: Command
Command that will execute unsubscribe.

Basic Usage​

Unsubscribe from a channel:


Unsubscribe from a channel group:


Unsubscribe from multiple channels:


Returns​

The unsubscribe() operation returns a PNStatus which contains the following operations:

MethodDescription
getCategory()
Type: Enum of type PNStatusCategory.
Details of PNStatusCategory are here
isError()
Type: Boolean
Is true in case of an error.
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