Presence API for PubNub 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.

Presence enables you to track the online and offline status of users and devices in real time, and store custom state information. Presence provides authoritative information on:

When a user has joined or left a channel
Who, and how many, users are subscribed to a particular channel
Which channel(s) an individual user is subscribed to
Associated state information for these users

Learn more about our Presence feature here.

Here Now

Requires Presence add-on

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

You can obtain information about the current state of a channel including a list of unique user-ids currently subscribed to the channel and the total occupancy count of the channel by calling the hereNow() function in your application.

Cache

This method has a 3 second response cache time.

Method(s)

To call Here Now you can use the following method(s) in the Java SDK:

this.pubnub.hereNow()
    .channels(Array)
    .channelGroups(Arrays)
    .includeState(true)
    .includeUUIDs(true)

Parameter	Type	Required	Default	Description
`channels`	Array	Optional		The `channels` to get the `here now` details.
`channelGroups`	Arrays	Optional		The `channelGroups` to get the `here now` details.
`includeState`	Boolean	Optional	`false`	If `true`, the response will include the presence states of the users for `channels`/`channelGroups`
`includeUUIDs`	Boolean	Optional	`true`	If `true`, the response will include the `UUIDs` of the connected clients.
`async`	`Consumer<Result>`	Yes		`Consumer` of a `Result` of type `PNHereNowResult`

Basic Usage

Get a list of UUIDs subscribed to channel

pubnub.hereNow()
    // tailor the next two lines to example
    .channels(Arrays.asList("coolChannel", "coolChannel2"))
    .includeUUIDs(true)
    .async(result -> {
        result.onSuccess(res -> {
            for (PNHereNowChannelData channelData : res.getChannels().values()) {
                System.out.println("---");
                System.out.println("channel:" + channelData.getChannelName());
                System.out.println("occupancy: " + channelData.getOccupancy());
                System.out.println("occupants:");
                for (PNHereNowOccupantData occupant : channelData.getOccupants()) {
                    System.out.println("uuid: " + occupant.getUuid() + " state: " + occupant.getState());
                }
            }
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Returns

The hereNow() operation returns a PNHereNowResult which contains the following operations:

Method	Type	Description
`getTotalChannels()`	Int	Total `Channels`.
`getTotalOccupancy()`	Int	Total `Occupancy`.
`getChannels()`	Map`<String, PNHereNowChannelData>`	A map with values of `PNHereNowChannelData` for each `channel`. See PNHereNowChannelData for more details.

PNHereNowChannelData

Method	Type	Description
`getChannelName()`	String	`Channel` name.
`getOccupancy()`	Int	`Occupancy` of the `channel`.
`getOccupants()`	List`<PNHereNowOccupantData>`	A list of `PNHereNowOccupantData`, see PNHereNowOccupantData for more details.

PNHereNowOccupantData

Method	Type	Description
`getUuid()`	String	`UUIDs` of the user.
`getState()`	Object	`State` of the user.

Other Examples

Returning State

Requires Presence add-on

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

pubnub.hereNow()
    .channels(Arrays.asList("my_channel")) // who is present on those channels?
    .includeState(true) // include state with request (false by default)
    .includeUUIDs(true) // if false, only shows occupancy count
    .async(result -> { /* check result */ });

Example Response

if (!status.isError()) {
    for (PNHereNowChannelData channelData : result.getChannels().values()) {
            channelData.getOccupancy(); // 3
            channelData.getChannelName(); // my_channel
            channelData.getOccupants(); // members of a channel
            for (PNHereNowOccupantData occupant : channelData.getOccupants()) {
                occupant.getUuid(); // some_uuid;
                occupant.getState(); // channel member state, if applicable
            }
    }
} else {
    // an error occurred
    status.getErrorData().getInformation();
    status.getErrorData().getThrowable().printStackTrace();
}

Return Occupancy Only

Requires Presence add-on

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

You can return only the occupancy information for a single channel by specifying the channel and setting UUIDs to false:

pubnub.hereNow()
    .channels(Arrays.asList("my_channel")) // who is present on those channels?
    .includeState(false) // include state with request (false by default)
    .includeUUIDs(false) // if false, only shows occupancy count
    .async(result -> { /* check result */ });

Example Response

if (!status.isError()) {
    for (PNHereNowChannelData channelData: result.getChannels().values()) {
        channelData.getOccupancy(); // 3
        channelData.getChannelName(); // my_channel
    }
} else {
    // an error occurred
    status.getErrorData().getInformation();
    status.getErrorData().getThrowable().printStackTrace();
}

Here Now for Channel Groups

pubnub.hereNow()
    .channelGroups(Arrays.asList("cg1", "cg2", "cg3")) // who is present on channel groups?
    .includeState(true) // include state with request (false by default)
    .includeUUIDs(true) // if false, only shows occupancy count
    .async(result -> { /* check result */ });

Example Response

if (!status.isError()) {
    result.getTotalOccupancy(); // 12
} else {
    // an error occurred
    status.getErrorData().getInformation();
    status.getErrorData().getThrowable().printStackTrace();
}

Where Now

Requires Presence add-on

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

You can obtain information about the current list of channels to which a UUID is subscribed to by calling the whereNow() function in your application.

Timeout events

If the app is killed/crashes and restarted (or the page containing the PubNub instance is refreshed on the browser) within the heartbeat window no timeout event is generated.

Method(s)

To call whereNow() you can use the following method(s) in the Java SDK:

pubnub.whereNow()
    .uuid(String)

Parameter	Type	Required	Description
`uuid`	String	Optional	`Uuid` of the user we want to spy on.
`async`	Command	Yes	Execute as `async`.

Basic Usage

You simply need to define the uuid and the callback function to be used to send the data to as in the example below.

Get a list of channels a UUID is subscribed to

pubnub.whereNow()
    .async(result -> { /* check result */ });

Returns

The whereNow() operation returns a PNWhereNowResult which contains the following operations:

Method	Type	Description
`getChannels()`	List`<String>`	The list of `channels` where the `UUID` is present.

Other Examples

Obtain information about the current list of channels of some other UUID

pubnub.whereNow()
    .uuid("some-other-uuid") // uuid of the user we want to spy on.
    .async(result -> { /* check result */ });

User State

Requires Presence add-on

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

The state API is used to set/get key/value pairs specific to a subscriber uuid.

State information is supplied as a JSON object of key/value pairs.

Presence state format

Presence state must be expressed as a JsonObject. When calling setState, be sure to supply an initialized JsonObject or POJO which can be serialized to a JsonObject.

Method(s)

Set State

this.pubnub.setPresenceState()
    .channels(Array)
    .channelGroups(Array)
    .state(HashMap)
    .uuid(String)

Parameter	Type	Required	Description
`channels`	Array	Optional	`Channels` to set `state`.
`channelGroups`	Array	Optional	`ChannelGroups` to set `state`.
`state`	HashMap	Optional	`State` to set.
`uuid`	String	Optional	Set `state` for specific `UUID`.
`async`	`Consumer<Result>`	Yes	`Consumer` of a `Result` of type `PNSetStateResult`.

Get State

this.pubnub.getPresenceState()
    .channels(Arrays)
    .channelGroups(Arrays)
    .uuid(String)

Parameter	Type	Required	Description
`channels`	Arrays	Optional	`Channel` name to fetch the `state`.
`channelGroups`	Arrays	Optional	`ChannelGroups` name to fetch the `state`.
`uuid`	String	Optional	`UUID`
`async`	`Consumer<Result>`	Yes	`Consumer` of a `Result` of type `PNGetStateResult`.

Basic Usage

Set State

JsonObject state = new JsonObject();
state.addProperty("is_typing", isTyping);

pubnub.setPresenceState()
    .channels(Arrays.asList(channel))
    .state(state)
    .async(result -> { /* check result */ });

Get State

pubnub.getPresenceState()
    .channels(Arrays.asList("ch1", "ch2", "ch3")) // channels to fetch state for
    .channelGroups(Arrays.asList("cg1", "cg2", "cg3")) // channel groups to fetch state for
    .uuid("suchUUID") // uuid of user to fetch, or for own uuid
    .async(result -> { /* check result */ });

Returns

The setPresenceState() operation returns a PNSetStateResult which contains the following operations:

Method	Type	Description
`getState()`	Map`<String, Object>`	Map of `UUIDs` and the user states.

The getPresenceState() operation returns a PNGetStateResult which contains the following operations:

Method	Type	Description
`getStateByUUID()`	Map`<String, Object>`	Map of `UUIDs` and the user states.

Other Examples

Set state for channels in channel group

JsonObject state = new JsonObject();
state.addProperty("is_typing", isTyping);

pubnub.setPresenceState()
    .channelGroups(Arrays.asList("cg1", "cg2", "cg3")) // apply on those channel groups
    .channels(Arrays.asList("ch1", "ch2", "ch3")) // apply on those channels
    .state(state) // the new state
    .async(result -> { /* check result */ });

The above code would return the following response to the client:

if (presence.getEvent().equals("state-change")) {
        boolean is_typing = presence.getState()
                            .getAsJsonObject()
                            .get("is_typing")
                            .getAsBoolean();
    }

Breaking changes in v9.0.0

Here Now​

Requires Presence add-on

Cache

Method(s)​

Basic Usage​

Get a list of UUIDs subscribed to channel​

Returns​

PNHereNowChannelData​

PNHereNowOccupantData​

Other Examples​

Returning State​

Requires Presence add-on

Example Response​

Return Occupancy Only​

Requires Presence add-on

Example Response​

Here Now for Channel Groups​

Example Response​

Where Now​

Requires Presence add-on

Timeout events

Method(s)​

Basic Usage​

Get a list of channels a UUID is subscribed to​

Returns​

Other Examples​

Obtain information about the current list of channels of some other UUID​

User State​

Requires Presence add-on

Presence state format

Method(s)​

Set State​

Get State​

Basic Usage​

Set State​

Get State​

Returns​

Other Examples​

Set state for channels in channel group​

Here Now

Method(s)

Basic Usage

Get a list of UUIDs subscribed to channel

Returns

PNHereNowChannelData

PNHereNowOccupantData

Other Examples

Returning State

Example Response

Return Occupancy Only

Example Response

Here Now for Channel Groups

Example Response

Where Now

Method(s)

Basic Usage

Get a list of channels a UUID is subscribed to

Returns

Other Examples

Obtain information about the current list of channels of some other UUID

User State

Method(s)

Set State

Get State

Basic Usage

Set State

Get State

Returns

Other Examples

Set state for channels in channel group