App Context 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.

This page describes App Context (formerly Objects v2). To upgrade from Objects v1, refer to the migration guide.

App Context provides easy-to-use, serverless storage for user and channel data you need to build innovative, reliable, scalable applications. Use App Context to store metadata about your application users and channels, and their membership associations, without running your own databases.

PubNub also triggers events when object data changes: set, update, or removal. Setting the same data again doesn't trigger an event. Clients can receive these events in real time and update their front-end application accordingly.

User

Get metadata for all users

Returns a paginated list of UUID metadata. Optionally includes Custom.

Method(s)

Use the following in the Java SDK:

1pubnub.getAllUUIDMetadata()
2    .limit(Integer)
3    .page(PNPage)
4    .filter(String)
5    .sort(List<PNSortKey>)
6    .includeTotalCount(Boolean)
7    .includeCustom(Boolean)

* required

Parameter	Description
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String? Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
includeTotalCount Type: Boolean Default: false	Whether to include the total count in the paginated response. Default is false.
includeCustom Type: Boolean Default: false	Whether to include the Custom object in the response.

Sample code

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.

1

Response

1public class PNGetAllUUIDMetadataResult extends EntityArrayEnvelope<PNUUIDMetadata> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNUUIDMetadata> data;
7    PNPage nextPage() {
8        return PNPage.next(next);
9    }
10    PNPage previousPage() {
11        return PNPage.previous(prev);
12    }
13}
14

15public class PNUUIDMetadata extends PNObject {
16    String id;
17    Object custom;
18    String updated;
19    String eTag;
20    String name;
21    String email;
22    String externalId;
23    String profileUrl;
24}

show all 24 lines

Get user metadata

Returns metadata for the specified UUID, optionally including the custom data object for each.

Method(s)

Use the following in the Java SDK:

1pubnub.getUUIDMetadata()
2    .uuid(String)
3    .includeCustom(Boolean)

* required

Parameter	Description
uuid Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.
includeCustom Type: Boolean Default: false	Whether to include the Custom object in the response.

Sample code

1

Response

1public class PNGetUUIDMetadataResult extends EntityEnvelope<PNUUIDMetadata> {
2    int status;
3    PNUUIDMetadata data;
4}
5

6public class PNUUIDMetadata extends PNObject {
7    String id;
8    Object custom;
9    String updated;
10    String eTag;
11    String name;
12    String email;
13    String externalId;
14    String profileUrl;
15}

Set user metadata

Unsupported partial updates of custom metadata

The value of the custom metadata parameter sent in this method always overwrites the value stored on PubNub servers. If you want to add new custom data to an existing one, you must:

1. Get the existing metadata and store it locally.
2. Append the new custom metadata to the existing one.
3. Set the entire updated custom object.

Set metadata for a UUID in the database, optionally including the custom data object for each.

Method(s)

Use the following in the Java SDK:

1pubnub.setUUIDMetadata()
2    .uuid(String)
3    .name(String)
4    .externalId(String)
5    .profileUrl(String)
6    .email(String)
7    .custom(Map<String, Object>)
8    .includeCustom(true)
9    .ifMatchesEtag(String)

* required

Parameter	Description
uuid Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.
name Type: String Default: n/a	Display name for the user.
externalId Type: String Default: n/a	User's identifier in an external system.
profileUrl Type: String Default: n/a	The URL of the user's profile picture.
email Type: String Default: n/a	The user's email address.
custom Type: Any Default: n/a	Custom JSON values. Can be strings, numbers, or booleans. Filtering by Custom isn’t supported.
includeCustom Type: Boolean Default: false	Whether to include the custom object in the fetch response.
ifMatchesEtag Type: String Default: n/a	Use the eTag from an applicable get metadata call to ensure updates only apply if the object hasn’t changed. If the eTags differ, the server returns HTTP 412.

API limits

To learn about the maximum length of parameters used to set user metadata, refer to REST API docs.

Sample code

1

Response

1public class PNSetUUIDMetadataResult extends EntityEnvelope<PNUUIDMetadata> {
2    protected int status;
3    protected PNUUIDMetadata data;
4}
5

6public class PNUUIDMetadata extends PNObject {
7    String id;
8    Object custom;
9    String updated;
10    String eTag;
11    String name;
12    String email;
13    String externalId;
14    String profileUrl;
15}

Remove user metadata

Removes the metadata from a specified UUID.

Method(s)

Use the following in the Java SDK:

1pubnub.removeUUIDMetadata()
2    .uuid(String)

* required

Parameter	Description
uuid Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.

Sample code

1

Response

1public class PNRemoveUUIDMetadataResult extends EntityEnvelope<JsonElement> {
2    int status;
3    JsonElement data;
4}

Channel

Get metadata for all channels

Returns a paginated list of channel metadata. Optionally includes Custom.

Method(s)

Use the following in the Java SDK:

1pubnub.getAllChannelsMetadata(
2        .limit(Integer)
3        .page(PNPage)
4        .filter(String)
5        .sort(List<PNSortKey>)
6        .includeTotalCount(Boolean)
7        .includeCustom(Boolean)

* required

Parameter	Description
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
includeTotalCount Type: Boolean Default: false	Whether to include the total count in the paginated response. Default is false.
includeCustom Type: Boolean Default: false	Whether to include the Custom object in the response.

Sample code

1

Response

1public class PNGetAllChannelsMetadataResult extends EntityArrayEnvelope<PNChannelMetadata> {
2    int status;
3    List<PNChannelMetadata> data;
4    Integer totalCount;
5    String next;
6    String prev;
7}
8

9public class PNChannelMetadata extends PNObject {
10    String id;
11    Object custom;
12    String updated;
13    String eTag;
14    String name;
15    String description;
16}

show all 16 lines

Get channel metadata

Returns metadata for the specified Channel, optionally including the custom data object for each.

Method(s)

Use the following in the Java SDK:

1pubnub.getChannelMetadata()
2    .channel(String)
3    .includeCustom(Boolean)

* required

Parameter	Description
channel * Type: String Default: n/a	Channel name.
includeCustom Type: Boolean Default: false	Whether to include the Custom object in the response.

Sample code

1

Response

1public class PNGetChannelMetadataResult extends EntityEnvelope<PNChannelMetadata> {
2    protected int status;
3    protected PNChannelMetadata data;
4}
5

6public class PNChannelMetadata extends PNObject {
7    String id;
8    Object custom;
9    String updated;
10    String eTag;
11    String name;
12    String description;
13}

Set channel metadata

Unsupported partial updates of custom metadata

The value of the custom metadata parameter sent in this method always overwrites the value stored on PubNub servers. If you want to add new custom data to an existing one, you must:

1. Get the existing metadata and store it locally.
2. Append the new custom metadata to the existing one.
3. Set the entire updated custom object.

Set metadata for a Channel in the database, optionally including the custom data object for each.

Method(s)

Use the following in the Java SDK:

1pubnub.setChannelMetadata()
2    .channel(String)
3    .name(String)
4    .description(String)
5    .custom(Map<String, Object>)
6    .includeCustom(Boolean)
7    .ifMatchesEtag(String)
8

* required

Parameter	Description
channel * Type: String Default: n/a	Channel ID.
name Type: String Default: n/a	Name for the channel.
description Type: String Default: n/a	Description of a channel.
custom Type: Map<String, Object> Default: n/a	Any object of key-value pairs with supported data types. App Context filtering language doesn’t support filtering by custom properties.
includeCustom Type: Boolean Default: false	Whether to include the custom object in the fetch response.
ifMatchesEtag Type: String Default: n/a	The entity tag to be used to ensure updates only happen if the object hasn't been modified since it was read. Use the eTag you received from an applicable get metadata method to check against the server entity tag. If the eTags don't match, an HTTP 412 error is thrown.

API limits

To learn about the maximum length of parameters used to set channel metadata, refer to REST API docs.

Sample code

1

Response

1public class PNSetChannelMetadataResult extends EntityEnvelope<PNChannelMetadata> {
2    protected int status;
3    protected PNChannelMetadata data;
4}
5

6public class PNChannelMetadata extends PNObject {
7    String id;
8    Object custom;
9    String updated;
10    String eTag;
11    String name;
12    String description;
13}

Other examples

Iteratively update existing metadata

1

Remove channel metadata

Removes the metadata from a specified channel.

Method(s)

Use the following in the Java SDK:

1pubnub.removeChannelMetadata()
2    .channel(String)

* required

Parameter	Description
channel * Type: String Default: n/a	Channel ID.

Sample code

1

Response

1public class PNRemoveChannelMetadataResult extends EntityEnvelope<JsonElement> {
2    int status;
3    protected JsonElement data;
4}

Channel memberships

Get channel memberships

Returns a list of channel memberships for a user. Does not include subscriptions.

Method(s)

Use the following in the Java SDK:

1pubnub.getMemberships()
2    .userId(String)
3    .limit(Integer)
4    .page(PNPage)
5    .filter(String)
6    .sort(List<PNSortKey>)
7    .include(MembershipInclude)
8    .async(result -> { /* check result */ });

* required

Parameter	Description
userId Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
include Type: MembershipInclude Default: All parameters set to false	Object holding the configuration for whether to include additional data in the response.

Sample code

1

Response

1public class PNGetMembershipsResult extends EntityArrayEnvelope<PNMembership> {
2    protected Integer totalCount;
3    protected String next;
4    protected String prev;
5    protected int status;
6    protected List<PNMembership> data;
7}
8

9public class PNMembership {
10    PNChannelMetadata channel;
11    Object custom;
12    String updated;
13    String eTag;
14}

Sample code with pagination

1

Set channel memberships

Set channel memberships for a User.

Method(s)

Use the following in the Java SDK:

1pubnub.setMemberships(Collection<PNChannelMembership>)
2    .userId(String)
3    .limit(Integer)
4    .page(PNPage)
5    .filter(String)
6    .sort(List<PNSortKey>)
7    .include(MembershipInclude)
8    .async(result -> { /* check result */ });

* required

Parameter	Description
channelMemberships * Type: List<PNChannelMembership> Default: n/a	Collection of PNChannelMembership to add to membership.
userId Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
include Type: MembershipInclude Default: All parameters set to false	Object holding the configuration for whether to include additional data in the response.

API limits

To learn about the maximum length of parameters used to set channel membership metadata, refer to REST API docs.

PNChannelMembership

PNChannelMembership is a utility class that uses the builder pattern to construct a channel membership with additional custom data.

* required

Parameter	Description
channel * Type: ChannelId	The name of the channel associated with this membership.
custom Type: Object	A dictionary that stores custom metadata related to the membership, allowing for additional context or information.
status Type: String	The status of the membership, for example: "active" or "inactive"
type Type: String	The type of membership for categorization purposes.

Sample code

1

Response

1public class PNSetMembershipResult extends EntityArrayEnvelope<PNMembership> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembership> data;
7}
8

9public class PNMembership {
10    PNChannelMetadata channel;
11    Object custom;
12    String updated;
13    String eTag;
14}

Remove channel memberships

Remove channel memberships for a User.

Method(s)

Use the following in the Java SDK:

1pubnub.removeMemberships(Collection<PNChannelMembership>)
2    .userId(String)
3    .limit(Integer)
4    .page(PNPage)
5    .filter(String)
6    .sort(List<PNSortKey>)
7    .include(MembershipInclude)
8    .async(result -> { /* check result */ });

* required

Parameter	Description
channelMemberships * Type: List<PNChannelMembership> Default: n/a	Collection of PNChannelMembership to add to membership.
userId Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
include Type: MembershipInclude Default: All parameters set to false	Object holding the configuration for whether to include additional data in the response.

Sample code

1

Response

1public class PNRemoveMembershipResults extends EntityArrayEnvelope<PNMembership> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembership> data;
7}
8

9public class PNMembership {
10    PNChannelMetadata channel;
11    Object custom;
12    String updated;
13    String eTag;
14}

Manage channel memberships

Manage a user's channel memberships.

Method(s)

Use the following in the Java SDK:

1pubnub.manageMemberships(Collection<PNChannelMembership>, Collection<String>)
2    .userId(String)
3    .limit(Integer)
4    .page(PNPage)
5    .filter(String)
6    .sort(List<PNSortKey>)
7    .include(MembershipInclude)
8    .async(result -> { /* check result */ });

* required

Parameter	Description
set * Type: Collection<PNChannelMembership> Default: n/a	List of members PNChannelMembership to add to channel.
remove * Type: Collection<Stirng> Default: n/a	List of members channelIds to remove from channel.
userId Type: String Default: pubnub.getConfiguration().getUserId().getValue()	Unique User Metadata identifier. If not supplied, then userId from configuration will be used.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
include Type: MembershipInclude Default: All parameters set to false	Object holding the configuration for whether to include additional data in the response.

Sample code

1

Response

1public class PNManageMembershipResult extends EntityArrayEnvelope<PNMembership> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembership> data;
7}
8

9public class PNMembership {
10    PNChannelMetadata channel;
11    Object custom;
12    String updated;
13    String eTag;
14}

Channel members

Get channel members

Returns a list of channel members. Includes user metadata when available.

Method(s)

Use the following in the Java SDK:

1pubnub.getChannelMembers(String)
2    .limit(Integer)
3    .page(PNPage)
4    .filter(String)
5    .sort(List<PNSortKey>)
6    .include(MemberInclude)
7    .async(result -> { /* check result */ });

* required

Parameter	Description
channel * Type: String Default: n/a	Channel ID.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
include Type: MemberInclude Default: All parameters set to false.	Object holding the configuration for whether to include additional data in the response.

Sample code

1

Response

1public class PNRemoveMembershipResults extends EntityArrayEnvelope<PNMembers> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembers> data;
7}
8

9public class PNMembers {
10    PNUUIDMetadata uuid;
11    Object custom;
12    String updated;
13    String eTag;
14}

Set channel members

This method sets members in a channel.

Method(s)

Use the following in the Java SDK:

1pubnub.setChannelMembers(String, Collection<PNUser>)
2    .limit(Integer)
3    .page(PNPage)
4    .filter(String)
5    .sort(List<PNSortKey>)
6    .include(MemberInclude)
7    .async(result -> { /* check result */ });

* required

Parameter	Description
channel * Type: String Default: n/a	Channel name.
channelMembers * Type: Collection<PNUser> Default: n/a	List of members to add to channel.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	Cursor-based pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	Sort by ID, NAME, UPDATED, STATUS, TYPE with asc/desc for sort direction (for example, PNSortKey.asc(PNSortKey.Key.TYPE)).
include Type: MemberInclude Default: All parameters set to false.	Object holding the configuration for whether to include additional data in the response.

API limits

To learn about the maximum length of parameters used to set channel members metadata, refer to REST API docs.

PNUser

PNUser is a utility class that utilizes the builder pattern to facilitate the construction of a user object with additional customization options. This class allows users to define custom metadata, a status, and a type for a user.

* required

Property	Description
userId * Type: String	The unique identifier for the user. This field cannot be null or empty.
custom Type: Object	A dictionary-like object that stores custom metadata related to the user, which provides additional context or information.
status Type: String	The status of the user, which can be any string such as active or inactive.
type Type: String	The categorization type of the user, allowing for differentiation between user types.

Sample code

1

Response

1public class PNSetChannelMembersResult extends EntityArrayEnvelope<PNMembers> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembers> data;
7}
8

9public class PNMembers {
10    PNUUIDMetadata uuid;
11    Object custom;
12    String updated;
13    String eTag;
14}

Remove channel members

Remove members from a Channel.

Method(s)

Use the following in the Java SDK:

1pubnub.removeChannelMembers(String, List<String>)
2    .limit(Integer)
3    .page(PNPage)
4    .filter(String)
5    .sort(List<PNSortKey>)
6    .includeTotalCount(Boolean)
7    .includeCustom(Boolean)
8    .includeUUID(PNUUIDDetailsLevel)

* required

Parameter	Description
channel * Type: String Default: n/a	Channel name.
channelMembers * Type: Collection<String> Default: n/a	List of member userIds to remove from channel.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	The paging object used for pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	List of properties to sort by. Available options are PNSortKey.Key.ID, PNSortKey.Key.NAME, PNSortKey.Key.UPDATED, PNSortKey.Key.STATUS and PNSortKey.Key.TYPE. Use PNSortKey.asc or PNSortKey.desc to specify sort direction. For example: PNSortKey.asc(PNSortKey.Key.TYPE) or PNSortKey.asc(PNSortKey.Key.STATUS)
include Type: MemberInclude Default: All parameters set to false	Object defining options to include additional data in the response.

Sample code

1

Response

1public class PNRemoveChannelMembersResult extends EntityArrayEnvelope<PNMembers> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembers> data;
7}
8

9public class PNMembers {
10    PNUUIDMetadata uuid;
11    Object custom;
12    String updated;
13    String eTag;
14}

Manage channel members

The method Set and Remove channel memberships for a user.

Method(s)

Use the following in the Java SDK:

1pubnub.manageChannelMembers(String, Collection<PNUser>, Collection<String>)
2    .limit(Integer)
3    .page(PNPage)
4    .filter(String)
5    .sort(List<PNSortKey>)
6    .include(MemberInclude)

* required

Parameter	Description
channel * Type: String Default: n/a	Channel name.
set * Type: Collection<PNUser> Default: n/a	List of members to add to channel.
remove * Type: Collection<String> Default: n/a	List of userIds to remove from channel.
limit Type: Integer Default: 100	Number of objects to return. Default/Max: 100.
page Type: PNPage Default: n/a	The paging object used for pagination.
filter Type: String Default: n/a	Filter expression. Only matching objects are returned. See filtering.
sort Type: List<PNSortKey> Default: listOf()	List of properties to sort by. Available options are PNSortKey.Key.ID, PNSortKey.Key.NAME, PNSortKey.Key.UPDATED, PNSortKey.Key.STATUS and PNSortKey.Key.TYPE. Use PNSortKey.asc or PNSortKey.desc to specify sort direction. For example: PNSortKey.asc(PNSortKey.Key.TYPE) or PNSortKey.asc(PNSortKey.Key.STATUS).
include Type: MemberInclude Default: All parameters set to false	Object holding the configuration for whether to include additional data in the response.

Sample code

1

Response

1public class PNManageChannelMembersResult extends EntityArrayEnvelope<PNMembers> {
2    Integer totalCount;
3    String next;
4    String prev;
5    int status;
6    List<PNMembers> data;
7}
8

9public class PNMembers {
10    PNUUIDMetadata uuid;
11    Object custom;
12    String updated;
13    String eTag;
14}