Channel Groups API for Java SDK

Breaking changes in v9.0.0

PubNub Java SDK version 9.0.0 unifies the codebases for Java and Kotlin 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 Java SDK.

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

Channel groups allow PubNub developers to bundle thousands of channels into a group that can be identified by a name. These channel groups can then be subscribed to, receiving data from the many back-end channels the channel group contains.

Channel group operations

You can't publish to a channel group. You can only subscribe to it. To publish within the channel group, you need to publish to each channel individually.

Add Channels

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.

This function adds a channel to a channel group.

Method(s)

Adding Channels is accomplished by using the following method(s) in the Java SDK:

Maximum number of channels

200 channels can be added to the channel group per API call.

this.pubnub.addChannelsToChannelGroup()
    .channelGroup(String)
    .channels(Array)

* required

Parameter	Description
channelGroup * Type: String	The channelGroup to add the channels to.
channels * Type: Array	The channel to add to the channel group.
async * Type: Consumer<Result>	Consumer of a Result of type PNChannelGroupsAddChannelResult

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.

Add Channels

import com.pubnub.api.PubNubException;
import com.pubnub.api.UserId;
import com.pubnub.api.java.PubNub;
import com.pubnub.api.java.v2.PNConfiguration;
import java.util.Arrays;

public class AddChannelsToChannelGroupApp {
    public static void main(String[] args) throws PubNubException {
        PNConfiguration.Builder configBuilder = PNConfiguration.builder(new UserId("demoUserId"), "demo");
        configBuilder.publishKey("demo");
        PubNub pubnub = PubNub.create(configBuilder.build());

        pubnub.addChannelsToChannelGroup()
                .channelGroup("cg1")
                .channels(Arrays.asList("ch1", "ch2", "ch3"))

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Response

The addChannelsToChannelGroup() does not return actionable data, be sure to check the status object on the outcome of the operation by checking the status.isError().

{
    "service" : "channel-registry",
    "status"  : 200,
    "error"   : false,
    "message" : "OK"
}

List Channels

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.

This function lists all the channels of the channel group.

Method(s)

Listing Channels is accomplished by using the following method(s) in the Java SDK:

pubnub.listChannelsForChannelGroup()
    .channelGroup(String)
    .async(result -> { /* check result */ });

* required

Parameter	Description
channelGroup * Type: String	Channel group to fetch the channels.
async * Type: Consumer<Result>	Consumer of a Result of type PNChannelGroupsAllChannelsResult.

Basic Usage

List Channels

pubnub.listChannelsForChannelGroup()
    .channelGroup("cg1")
    .async(result -> { /* check result */ });

Returns

The listChannelsForChannelGroup() operation returns a PNChannelGroupsAllChannelsResult which contains the following operations:

Method	Description
getChannels() Type: List<String>	List of channels of a channel group.

Remove Channels

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.

This function removes the channels from the channel group.

Method(s)

Removing Channels is accomplished by using the following method(s) in the Java SDK:

pubnub.removeChannelsFromChannelGroup()
    .channelGroup(String)
    .channels(Array)

* required

Parameter	Description
channels * Type: Array	The channels to remove from the channel group.
channelGroup * Type: String	Specifies channelGroup to remove the channels from.
async Type: Consumer<Result>	Consumer of a Result of type PNChannelGroupsRemoveChannelResult.

Basic Usage

Remove channels

pubnub.removeChannelsFromChannelGroup()
    .channelGroup("family")
    .channels(Arrays.asList("son"))
    .async(result -> { /* check result */ });

Response

The removeChannelsFromChannelGroup() does not return actionable data, be sure to check the status object on the outcome of the operation by checking the status.isError().

{
    "status" : 200,
    "message" : "OK",
    "service" : "channel-registry",
    "error" : False
}

Delete 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.

This function removes the channel group.

Method(s)

Deleting Channel Group is accomplished by using the following method(s) in the Java SDK:

pubnub.deleteChannelGroup()
    .channelGroup(String)

* required

Parameter	Description
channelGroup * Type: String	Specifies channelGroup to remove.
async Type: Consumer<Result>	Consumer of a Result of type PNChannelGroupsDeleteGroupResult.

Basic Usage

Delete Channel Group

pubnub.deleteChannelGroup()
    .channelGroup("family")
    .async(result -> { /* check result */ });

Response

The deleteChannelGroup() does not return actionable data, be sure to check the status object on the outcome of the operation by checking the status.isError().

{
    "status" : 200,
    "message" : "OK",
    "service" : "channel-registry",
    "error" : False
}