Message Persistence API for Android SDK

Message Persistence gives you real-time access to the history of messages published to PubNub. Each message is timestamped to the nearest 10 nanoseconds and stored across multiple availability zones in several geographic locations. You can encrypt stored messages with AES-256 so they are not readable on PubNub’s network. For details, see Message Persistence.

You control how long messages are stored through your account’s retention policy. Options include: 1 day, 7 days, 30 days, 3 months, 6 months, 1 year, or Unlimited.

You can retrieve the following:

Messages
Message reactions
Files (using the File Sharing API)

Fetch history

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

Fetch historical messages from one or multiple channels. Use includeMessageActions to include message reactions along with the messages.

You can control how messages are returned and in what order:

If you specify only the start parameter (without end), you receive messages older than the start timetoken.
If you specify only the end parameter (without start), you receive messages from that end timetoken and newer.
If you specify both start and end, you retrieve messages between those timetokens (inclusive of the end value).

You can receive up to 100 messages for a single channel, or 25 messages per channel when querying multiple channels (up to 500 channels). If more messages match the time range, make iterative calls and adjust the start timetoken to page through the results.

Method(s)

To run Fetch History, you can use the following method(s) in the Android SDK:

this.pubnub.fetchMessages()
    .channels(List<String>)
    .start(Long)
    .end(Long)
    .maximumPerChannel(Integer)
    .includeMeta(Boolean)
    .includeMessageActions(Boolean)
    .includeMessageType(Boolean)
    .includeUUID(Boolean)

* required

Parameter	Description
`channels` * Type: List`<String>` Default: n/a	Channels to fetch history messages from (up to 500).
`start` Type: Long Default: n/a	Timetoken delimiting the start of the time slice (exclusive) to pull messages from.
`end` Type: Long Default: n/a	Timetoken delimiting the end of the time slice (inclusive) to pull messages from.
`maximumPerChannel` Type: Integer Default: `100` or `25`	Number of historical messages to return per channel. Maximum is 100 for a single channel or 25 for multiple channels.
`includeMeta` Type: Boolean Default: `false`	Whether to include message metadata in the response.
`includeMessageActions` Type: Boolean Default: `false`	Retrieve history messages with message reactions. If `true`, limited to one channel only.
`includeMessageType` Type: Boolean Default: `true`	Whether to include message type. If `includeMessageActions` is `true`, then `25` is the default and maximum.
`includeUUID` Type: Boolean Default: `true`	Whether to include the publisher UUID.
`async` * Type: PNCallback Default: n/a	`PNCallback` of type `PNFetchMessagesResult`.

Truncated response

If you fetch messages with message actions, the response may be truncated when internal limits are reached. If truncated, a more property is returned with additional parameters. Make iterative calls to history, adjusting the parameters to fetch more messages.

Sample code

Retrieve the last message on a channel:

pubnub.fetchMessages()
        .channels(Arrays.asList("my_channel"))
        .maximumPerChannel(25)
        .includeMessageActions(true)
        .includeMeta(true)
        .includeMessageType(true)
        .includeUUID(true)
        .async(new PNCallback<PNFetchMessagesResult>() {
            @Override
            public void onResponse(PNFetchMessagesResult result, PNStatus status) {
                if (!status.isError()) {
                    Map<String, List<PNFetchMessageItem>> channels = result.getChannels();
                    for (PNFetchMessageItem messageItem : channels.get("my_channel")) {
                        System.out.println(messageItem.getMessage());
                        System.out.println(messageItem.getMeta());
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Returns

The fetchMessages() operation returns a list of PNFetchMessagesResult objects, each containing the following operations:

Method	Description
`getMessage()` Type: JsonElement	Message content.
`getMeta()` Type: JsonElement	Message metadata if any, and if requested via `includeMeta(true)`.
`getTimetoken()` Type: Long	Publish timetoken.
`getActionTimetoken()` Type: Long	Timestamp when the message reaction was created.
`getActions()` Type: HashMap	Actions data of the message, if any, and if requested via `includeMessageActions(true)`.
`getMessageType()` Type: Integer	Message type `0` - message, `1` - signal, `2` - object, `3` - message reaction, `4` - files
`getUuid()` Type: String	UUID of the publisher

Other examples

Paging history responses

package com.we.pubnubtest.utils;

import com.pubnub.api.models.consumer.history.PNFetchMessagesResult;

public abstract class CallbackSkeleton {

    public CallbackSkeleton() {
    }

    public abstract void handleResponse(PNFetchMessagesResult result);

    public abstract void finish();

}

package com.we.pubnubtest.utils;

import com.pubnub.api.PubNub;
import com.pubnub.api.callbacks.PNCallback;
import com.pubnub.api.models.consumer.PNStatus;
import com.pubnub.api.models.consumer.history.PNFetchMessagesResult;
import com.pubnub.api.models.consumer.pubsub.PNMessageResult;

import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CountDownLatch;

public class PubnubRecursiveHistoryFetcher {
    private PubNub pubNub;
    private String channels;
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Fetch messages from multiple channels

pubNub.fetchMessages()
.channels(Arrays.asList("ch1", "ch2", "ch3"))
.async(new PNCallback<PNFetchMessagesResult>() {
    @Override
    public void onResponse(@Nullable final PNFetchMessagesResult result, @NotNull final PNStatus status) {
        if (!status.isError()) {
            final Map<String, List<PNFetchMessageItem>> channelToMessageItemsMap = result.getChannels();
            final Set<String> channels = channelToMessageItemsMap.keySet();
            for (final String channel : channels) {
                List<PNFetchMessageItem> pnFetchMessageItems = channelToMessageItemsMap.get(channel);
                for (final PNFetchMessageItem fetchMessageItem: pnFetchMessageItems) {
                    System.out.println(fetchMessageItem.getMessage());
                    System.out.println(fetchMessageItem.getMeta());
                    System.out.println(fetchMessageItem.getTimetoken());
                }
show all 22 lines

Delete messages from history

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

Remove messages from the history of a specific channel.

Required setting

To accept delete-from-history requests, enable the Delete-From-History setting for your key in the Admin Portal and initialize the SDK with a secret key.

Method(s)

To Delete Messages from History you can use the following method(s) in the Android SDK.

this.pubnub.deleteMessages()
    .channels(Array)
    .start(Long)
    .end(Long)

* required

Parameter	Description
`channels` * Type: Array Default: n/a	Channels to delete messages from.
`start` Type: Long Default: n/a	Timetoken delimiting the start of the time slice (inclusive) to delete messages from.
`end` Type: Long Default: n/a	Timetoken delimiting the end of the time slice (exclusive) to delete messages from.
`async` * Type: PNCallback Default: n/a	`PNCallback` of type `PNDeleteMessagesResult`.

Sample code

pubnub.deleteMessages()
    .channels(Arrays.asList("channel_1", "channel_2"))
    .start(1460693607379L)
    .end(1460893617271L)
    .async(new PNCallback<PNDeleteMessagesResult>() {
        @Override
        public void onResponse(PNDeleteMessagesResult result, PNStatus status) {
            // The deleteMessages() method does not return actionable data, be sure to check the status
            // object on the outcome of the operation by checking the status.isError().
        }
    });

Other examples

Delete specific message from history

To delete a specific message, pass the publish timetoken (received from a successful publish) in the End parameter and timetoken +/- 1 in the Start parameter. For example, if 15526611838554310 is the publish timetoken, pass 15526611838554309 in Start and 15526611838554310 in End parameters respectively as shown in the following code snippet.

pubnub.deleteMessages()
    .channels(Arrays.asList("channel_1"))
    .start(15526611838554309L)
    .end(15526611838554310L)
    .async(new PNCallback<PNDeleteMessagesResult>() {
        @Override
        public void onResponse(PNDeleteMessagesResult result, PNStatus status) {
            // The deleteMessages() method does not return actionable data, be sure to check the status
            // object on the outcome of the operation by checking the status.isError().
        }
    });

Message counts

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

Return the number of messages published on one or more channels since a given time. The count is the number of messages in history with a timetoken greater than or equal to the value passed in channelsTimetoken.

Unlimited message retention

For keys with unlimited message retention enabled, this method considers only messages published in the last 30 days.

Method(s)

You can use the following method(s) in the Android SDK:

this.pubnub.messageCounts()
    .channels(Array)
    .channelsTimetoken(Array)

* required

Parameter	Description
`channels` * Type: Array Default: n/a	Channels to fetch the message count for.
`channelsTimetoken` * Type: Array Default: n/a	List of `timetokens`, in the same order as the channels list. Specify a single `timetoken` to apply it to all channels. Otherwise, the list of `timetokens` must match the number of channels, or the function returns a `PNStatus` error.
`async` * Type: PNCallback Default: n/a	PNCallback of type `PNMessageCountResult`.

Sample code

Long lastHourTimetoken = (Calendar.getInstance().getTimeInMillis() - TimeUnit.HOURS.toMillis(1)) * 10000L;

pubnub.messageCounts()
    .channels(Arrays.asList("news"))
    .channelsTimetoken(Arrays.asList(lastHourTimetoken))
    .async(new PNCallback<PNMessageCountResult>() {
        @Override
        public void onResponse(PNMessageCountResult result, PNStatus status) {
            if (!status.isError()) {
                for (Map.Entry<String, Long> messageCountEntry : result.getChannels().entrySet()) {
                    messageCountEntry.getKey(); // the channel name
                    messageCountEntry.getValue(); // number of messages for that channel
                }
            } else {
                // Handle error accordingly.
show all 19 lines

Returns

The operation returns a PNMessageCountResult which contains the following properties:

Method	Description
`getChannels()` Type: Map`<String, Long>`	A map with values of `Long` for each channel. `Channels` without messages have a count of 0. `Channels` with 10,000 messages or more have a count of 10000.

Other examples

Retrieve count of messages using different timetokens for each channel

Long lastHourTimetoken = (Calendar.getInstance().getTimeInMillis() - TimeUnit.HOURS.toMillis(1)) * 10000L;
Long lastDayTimetoken = (Calendar.getInstance().getTimeInMillis() - TimeUnit.DAYS.toMillis(1)) * 10000L;

pubnub.messageCounts()
    .channels(Arrays.asList("news", "info"))
    .channelsTimetoken(Arrays.asList(lastHourTimetoken, lastDayTimetoken))
    .async(new PNCallback<PNMessageCountResult>() {
        @Override
        public void onResponse(PNMessageCountResult result, PNStatus status) {
            if (!status.isError()) {
                for (Map.Entry<String, Long> messageCountEntry : result.getChannels().entrySet()) {
                    messageCountEntry.getKey(); // the channel name
                    messageCountEntry.getValue(); // number of messages for that channel
                }
            } else {
show all 20 lines

History (deprecated)

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

Alternative method

This method is deprecated. Use fetch history instead.

Fetch historical messages for a channel.

You can control how messages are returned and in what order. For example, you can:

Search from the newest end of the timeline (default: reverse = false).
Search from the oldest end of the timeline by setting reverse to true.
Page through results by providing a start or end timetoken.
Retrieve a slice of the timeline by providing both a start and end timetoken.
Limit the number of messages using the count parameter.

Start & End parameter usage clarity

If you specify only start (without end), you receive messages older than and up to that start timetoken. If you specify only end (without start), you receive messages that match that end timetoken and newer. If you specify both start and end, you receive messages between those timetokens (inclusive of end). You still receive up to 100 messages even if more match. Make iterative calls to history, adjusting start, to page through the full result set.

Method(s)

To run History you can use the following method(s) in the Android SDK:

this.pubnub.history()
    .channel(String)
    .reverse(Boolean)
    .includeTimetoken(Boolean)
    .includeMeta(Boolean)
    .start(Long)
    .end(Long)
    .count(Integer);

* required

Parameter	Description
`channel` * Type: String Default: n/a	Channel to return history messages from.
`reverse` Type: Boolean Default: `false`	Whether to traverse the timeline in reverse (oldest to newest) when set to `true`.
`includeTimetoken` Type: Boolean Default: `false`	Whether event dates `timetokens` should be included in the response.
`includeMeta` Type: Boolean Default: `false`	Whether to include message metadata within the response.
`start` Type: Long Default: n/a	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
`end` Type: Long Default: n/a	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
`count` Type: Int Default: `100`	Number of historical messages to return.
`async` * Type: PNCallback Default: n/a	`PNCallback` of type `PNHistoryResult`.

Using the reverse parameter

Messages are always returned sorted in ascending time direction from history regardless of reverse. The reverse direction matters when you have more than 100 (or count, if it's set) messages in the time interval, in which case reverse determines the end of the time interval from which it should start retrieving the messages.

Sample code

Retrieve the last 100 messages on a channel:

pubnub.history()
    .channel("history_channel") // where to fetch history from
    .count(100) // how many items to fetch
    .async(new PNCallback<PNHistoryResult>() {
        @Override
        public void onResponse(PNHistoryResult result, PNStatus status) {

        }
    });

Returns

The history() operation returns a PNHistoryResult which contains the following properties:

Method	Description
`getMessages()` Type: List`<PNHistoryItemResult>`	List of messages. See PNHistoryItemResult for more details.
`getStartTimetoken()` Type: Long	Start `timetoken`.
`getEndTimetoken()` Type: Long	End `timetoken`.

PNHistoryItemResult

Method	Description
`getTimetoken()` Type: Long	`Timetoken` of the message.
`getEntry()` Type: JsonElement	Message.

Other examples

Use history() to retrieve the three oldest messages by retrieving from the time line in reverse

pubnub.history()
    .channel("my_channel") // where to fetch history from
    .count(3) // how many items to fetch
    .reverse(true) // should go in reverse?
    .async(new PNCallback<PNHistoryResult>() {
        @Override
        public void onResponse(PNHistoryResult result, PNStatus status) {

        }
    });

Response

if (!status.isError()) {
    for (PNHistoryItemResult pnHistoryItemResult: result.getMessages()) {
        pnHistoryItemResult.getEntry(); // custom JSON structure for message
    }
}

Use history() to retrieve messages newer than a given timetoken by paging from oldest message to newest message starting at a single point in time (exclusive)

pubnub.history()
    .channel("my_channel") // where to fetch history from
    .start(13847168620721752L) // first timestamp
    .reverse(true) // should go in reverse?
    .async(new PNCallback<PNHistoryResult>() {
        @Override
        public void onResponse(PNHistoryResult result, PNStatus status) {

        }
    });

Response

if (!status.isError()) {
    for (PNHistoryItemResult pnHistoryItemResult: result.getMessages()) {
        pnHistoryItemResult.getEntry(); // custom JSON structure for message
    }
}

Use history() to retrieve messages until a given timetoken by paging from newest message to oldest message until a specific end point in time (inclusive)

pubnub.history()
    .channel("my_channel") // where to fetch history from
    .count(100) // how many items to fetch
    .start(-1) // first timestamp
    .end(13847168819178600L) // last timestamp
    .reverse(true) // should go in reverse?
    .async(new PNCallback<PNHistoryResult>() {
        @Override
        public void onResponse(PNHistoryResult result, PNStatus status) {

        }
    });

Response

[
    ["Pub3","Pub4","Pub5"],
    13406746780720711,
    13406746845892666
]

History paging example

Usage

You can call the method by passing 0 or a valid timetoken as the argument.

package com.pubnub.api;

import com.pubnub.api.v2.PNConfiguration;
import com.pubnub.api.PubNub;
import com.pubnub.api.callbacks.PNCallback;
import com.pubnub.api.models.consumer.PNStatus;
import com.pubnub.api.models.consumer.history.PNHistoryItemResult;
import com.pubnub.api.models.consumer.history.PNHistoryResult;

public class PubNubRecursiveHistoryFetcher {

    private PubNub pubnub;

    private static abstract class CallbackSkeleton {
        public abstract void handleResponse(PNHistoryResult result);
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Include timetoken in history response

pubnub.history()
    .channel("history_channel") // where to fetch history from
    .count(100) // how many items to fetch
    .includeTimetoken(true) // include timetoken with each entry
    .async(new PNCallback<PNHistoryResult>() {
        @Override
        public void onResponse(PNHistoryResult result, PNStatus status) {

        }
    });

Fetch history​

Requires Message Persistence

Method(s)​

Truncated response

Sample code​

Returns​

Other examples​

Paging history responses​

Fetch messages from multiple channels​

Delete messages from history​

Requires Message Persistence

Required setting

Method(s)​

Sample code​

Other examples​

Delete specific message from history​

Message counts​

Requires Message Persistence

Unlimited message retention

Method(s)​

Sample code​

Returns​

Other examples​

Retrieve count of messages using different timetokens for each channel​

History (deprecated)​

Requires Message Persistence

Alternative method

Start & End parameter usage clarity

Method(s)​

Using the reverse parameter

Sample code​

Returns​

PNHistoryItemResult​

Other examples​

Use history() to retrieve the three oldest messages by retrieving from the time line in reverse​

Response​

Use history() to retrieve messages newer than a given timetoken by paging from oldest message to newest message starting at a single point in time (exclusive)​

Response​

Use history() to retrieve messages until a given timetoken by paging from newest message to oldest message until a specific end point in time (inclusive)​

Response​

History paging example​

Usage

Include timetoken in history response​

Fetch history

Method(s)

Sample code

Returns

Other examples

Paging history responses

Fetch messages from multiple channels

Delete messages from history

Method(s)

Sample code

Other examples

Delete specific message from history

Message counts

Method(s)

Sample code

Returns

Other examples

Retrieve count of messages using different timetokens for each channel

History (deprecated)

Method(s)

Sample code

Returns

PNHistoryItemResult

Other examples

Use history() to retrieve the three oldest messages by retrieving from the time line in reverse

Response

Use history() to retrieve messages newer than a given timetoken by paging from oldest message to newest message starting at a single point in time (exclusive)

Response

Use history() to retrieve messages until a given timetoken by paging from newest message to oldest message until a specific end point in time (inclusive)

Response

History paging example

Include timetoken in history response