Telegram Component

Available as of Camel 2.18

The Telegram component provides access to the Telegram Bot API. It allows a Camel-based application to send and receive messages by acting as a Bot, participating in direct conversations with normal users, private and public groups or channels.

A Telegram Bot must be created before using this component, following the instructions at the Telegram Bot developers home. When a new Bot is created, the BotFather provides an authorization token corresponding to the Bot. The authorization token is a mandatory parameter for the camel-telegram endpoint.

Note

In order to allow the Bot to receive all messages exchanged within a group or channel (not just the ones starting with a / character), ask the BotFather to disable the privacy mode, using the /setprivacy command.

Maven users will need to add the following dependency to their pom.xml for this component:

URI Format

Options

The Telegram component has no options. However, the Telegram component does support 24 endpoint options, which are listed below:

NameGroupDefaultDescription

authorizationToken

common

 

Required The authorization token for using the bot (ask the BotFather) e.g., 654321531:HGF_dTra456323dHuOedsE343211fqr3t-H.

type

common

 

Required The endpoint type. Currently only the bots type is supported.

bridgeErrorHandler

consumer

false

Allows for bridging the consumer to the Camel routing Error Handler which mean any exceptions occurred while the consumer is trying to pickup incoming messages or the likes will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions that will be logged at WARN/ERROR level and ignored.

limit

consumer

100

Limit on the number of updates that can be received in a single polling request.

sendEmptyMessageWhenIdle

consumer

false

If the polling consumer did not poll any files you can enable this option to send an empty message (no body) instead.

timeout

consumer

30

Timeout in seconds for long polling. Put 0 for short polling or a bigger number for long polling. Long polling produces shorter response time.

exceptionHandler

consumer 

(advanced)

 

To let the consumer use a custom ExceptionHandler.

Note: if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions that will be logged at WARN/ERROR level and ignored.

pollStrategy

consumer 

(advanced)

 

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

chatId

producer

 

The identifier of the chat that will receive the produced messages. Chat ids can be first obtained from incoming messages e.g., when a telegram user starts a conversation with a bot its client sends automatically a /start message containing the chat id. It is an optional parameter as the chat id can be set dynamically for each outgoing message (using body or headers).

exchangePattern

advanced

InOnly

Sets the default exchange pattern when creating an exchange

synchronous

advanced

false

Sets whether synchronous processing should be strictly used or Camel is allowed to use asynchronous processing (if supported).

backoffErrorThreshold

scheduler

 

The number of subsequent error polls (failed due some error) that should happen before the backoffMultiplier should kick-in.

backoffIdleThreshold

scheduler

 

The number of subsequent idle polls that should happen before the backoffMultiplier should kick-in.

backoffMultiplier

scheduler

 

To let the scheduled polling consumer back-off if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

delay

scheduler

500

Milliseconds before the next poll. You can also specify time values using units such as:

  • 60s (60 seconds)
  • 5m30s (5 minutes and 30 seconds)
  • 1h (1 hour)

greedy

scheduler

false

If greedy is enabled then the ScheduledPollConsumer will run immediately again if the previous run polled 1 or more messages.

initialDelay

scheduler

1000

Milliseconds before the first poll starts. You can also specify time values using units such as:

  • 60s (60 seconds)
  • 5m30s (5 minutes and 30 seconds)
  • 1h (1 hour)

runLoggingLevel

scheduler

TRACE

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

scheduledExecutorService

scheduler

 

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

scheduler

scheduler

none

To use a cron scheduler from either camel-spring or camel-quartz2 component

schedulerProperties

scheduler

 

To configure additional properties when using a custom scheduler or any of the Quartz2 Spring based scheduler.

startScheduler

scheduler

true

Whether the scheduler should be auto started.

timeUnit

scheduler

ms

Time unit for initialDelay and delay options.

useFixedDelay

scheduler

true

Controls if fixed delay or fixed rate is used.

See ScheduledExecutorService in JDK for details.

Message Headers

NameDescription

CamelTelegramChatId

This header is used by the producer endpoint in order to resolve the chat id that will receive the message. The recipient chat id can be placed (in order of priority) in message body, in the CamelTelegramChatId header or in the endpoint configuration (chatId option). This header is also present in all incoming messages.

CamelTelegramMediaType

This header is used to identify the media type when the outgoing message is composed of pure binary data. Possible values are strings or enum values belonging to the org.apache.camel.component.telegram.TelegramMediaType enumeration.

CamelTelegramMediaTitleCaption

This header is used to provide a caption or title for outgoing binary messages.

Usage

The Telegram component supports both consumer and producer endpoints. It can also be used in reactive chat-bot mode (to consume, then produce messages).

Producer Example

The following is a basic example of how to send a message to a Telegram chat through the Telegram Bot API.

in Java DSL:

or in Spring XML:

The code 123456789:AAE_dLq5C19xwGjw3yiC2NvEUrZcejK21-Q987654321:AAE_dLq5C19xwOmg5yiC2NvSrkT3wj5Q1-L is the authorization token corresponding to the Bot.

When using the producer endpoint without specifying the chat id option, the target chat will be identified using information contained in the body or headers of the message. The following message bodies are allowed for a producer endpoint (messages of type OutgoingXXXMessage belong to the package org.apache.camel.component.telegram.model)

Java TypeDescription

OutgoingTextMessage

To send a text message to a chat.

OutgoingPhotoMessage

To send a photo (JPG, PNG) to a chat.

OutgoingAudioMessage

To send a mp3 audio to a chat.

OutgoingVideoMessage

To send a mp4 video to a chat.

byte[]

To send any media type supported. It requires the CamelTelegramMediaType header to be set to the appropriate media type.

String

To send a text message to a chat. It gets converted automatically into a OutgoingTextMessage

Consumer Example

The following is a basic example of how to receive all messages that telegram users are sending to the configured Bot.

In Java DSL:

or in Spring XML:

The MyBean is a simple bean that will receive the messages:

Supported types for incoming messages are

Java TypeDescription

IncomingMessage

The full object representation of an incoming message

String

The content of the message, for text messages only

Reactive Chat-Bot Example

The reactive chat-bot mode is a simple way of using the Camel component to build a simple chat bot that replies directly to chat messages received from the Telegram users.

The following is a basic configuration of the chat-bot in Java DSL

or in Spring XML

The ChatBotLogic is a simple bean that implements a generic String-to-String method.

Every non-null string returned by the chatBotProcess() method is automatically routed to the chat that originated the request (as the CamelTelegramChatId header is used to route the message).

© 2004-2015 The Apache Software Foundation.
Apache Camel, Camel, Apache, the Apache feather logo, and the Apache Camel project logo are trademarks of The Apache Software Foundation. All other marks mentioned may be trademarks or registered trademarks of their respective owners.
Graphic Design By Hiram