Atom

Since Camel 1.2

The atom: component is used for polling Atom feeds.

Camel will poll the feed every 60 seconds by default.

 *Note:* The component currently only supports polling (consuming)
feeds.

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

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-atom</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

atom://atomUri[?options]

Where atomUri is the URI to the Atom feed to poll.

Options

The Atom component has no options.

The Atom endpoint is configured using URI syntax:

atom:feedUri

with the following path and query parameters:

Path Parameters (1 parameters):

Name	Description	Default	Type
feedUri	Required The URI to the feed to poll.		String

Name

Description

Default

Type

feedUri

Required The URI to the feed to poll.

String

Query Parameters (27 parameters):

Name	Description	Default	Type
bridgeErrorHandler (consumer)	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 or ERROR level and ignored.	false	boolean
feedHeader (consumer)	Sets whether to add the feed object as a header	true	boolean
filter (consumer)	Sets whether to use filtering or not of the entries.	true	boolean
lastUpdate (consumer)	Sets the timestamp to be used for filtering entries from the atom feeds. This options is only in conjunction with the splitEntries.		Date
password (consumer)	Sets the password to be used for basic authentication when polling from a HTTP feed		String
sendEmptyMessageWhenIdle (consumer)	If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.	false	boolean
sortEntries (consumer)	Sets whether to sort entries by published date. Only works when splitEntries = true.	false	boolean
splitEntries (consumer)	Sets whether or not entries should be sent individually or whether the entire feed should be sent as a single message	true	boolean
throttleEntries (consumer)	Sets whether all entries identified in a single feed poll should be delivered immediately. If true, only one entry is processed per consumer.delay. Only applicable when splitEntries = true.	true	boolean
username (consumer)	Sets the username to be used for basic authentication when polling from a HTTP feed		String
exceptionHandler (consumer)	To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.		ExceptionHandler
exchangePattern (consumer)	Sets the exchange pattern when the consumer creates an exchange.		ExchangePattern
pollStrategy (consumer)	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.		PollingConsumerPoll Strategy
synchronous (advanced)	Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).	false	boolean
backoffErrorThreshold (scheduler)	The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.		int
backoffIdleThreshold (scheduler)	The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.		int
backoffMultiplier (scheduler)	To let the scheduled polling consumer backoff 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.		int
delay (scheduler)	Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).	500	long
greedy (scheduler)	If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.	false	boolean
initialDelay (scheduler)	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), and 1h (1 hour).	1000	long
runLoggingLevel (scheduler)	The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.	TRACE	LoggingLevel
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.		ScheduledExecutor Service
scheduler (scheduler)	To use a cron scheduler from either camel-spring or camel-quartz2 component	none	ScheduledPollConsumer Scheduler
schedulerProperties (scheduler)	To configure additional properties when using a custom scheduler or any of the Quartz2, Spring based scheduler.		Map
startScheduler (scheduler)	Whether the scheduler should be auto started.	true	boolean
timeUnit (scheduler)	Time unit for initialDelay and delay options.	MILLISECONDS	TimeUnit
useFixedDelay (scheduler)	Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.	true	boolean

Name

Description

Default

Type

bridgeErrorHandler (consumer)

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 or ERROR level and ignored.

false

boolean

feedHeader (consumer)

Sets whether to add the feed object as a header

true

boolean

filter (consumer)

Sets whether to use filtering or not of the entries.

true

boolean

lastUpdate (consumer)

Sets the timestamp to be used for filtering entries from the atom feeds. This options is only in conjunction with the splitEntries.

Date

password (consumer)

Sets the password to be used for basic authentication when polling from a HTTP feed

String

sendEmptyMessageWhenIdle (consumer)

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

false

boolean

sortEntries (consumer)

Sets whether to sort entries by published date. Only works when splitEntries = true.

false

boolean

splitEntries (consumer)

Sets whether or not entries should be sent individually or whether the entire feed should be sent as a single message

true

boolean

throttleEntries (consumer)

Sets whether all entries identified in a single feed poll should be delivered immediately. If true, only one entry is processed per consumer.delay. Only applicable when splitEntries = true.

true

boolean

username (consumer)

Sets the username to be used for basic authentication when polling from a HTTP feed

String

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer)

Sets the exchange pattern when the consumer creates an exchange.

ExchangePattern

pollStrategy (consumer)

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.

PollingConsumerPoll Strategy

synchronous (advanced)

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

false

boolean

backoffErrorThreshold (scheduler)

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

int

backoffIdleThreshold (scheduler)

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

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff 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.

int

delay (scheduler)

Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

500

long

greedy (scheduler)

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

false

boolean

initialDelay (scheduler)

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), and 1h (1 hour).

1000

long

runLoggingLevel (scheduler)

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

TRACE

LoggingLevel

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.

ScheduledExecutor Service

scheduler (scheduler)

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

none

ScheduledPollConsumer Scheduler

schedulerProperties (scheduler)

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

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

true

boolean

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-atom-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 2 options, which are listed below.

Name	Description	Default	Type
camel.component.atom.enabled	Enable atom component	true	Boolean
camel.component.atom.resolve-property-placeholders	Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.	true	Boolean

Name

Description

Default

Type

camel.component.atom.enabled

Enable atom component

true

Boolean

camel.component.atom.resolve-property-placeholders

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

Boolean

You can append query options to the URI in the following format, ?option=value&option=value&…

Exchange data format

Camel will set the In body on the returned Exchange with the entries. Depending on the splitEntries flag Camel will either return one Entry or a List<Entry>.

Option Value Behavior

Option	Value	Behavior
`splitEntries`	`true`	Only a single entry from the currently being processed feed is set: `exchange.in.body(Entry)`
`splitEntries`	`false`	The entire list of entries from the feed is set: `exchange.in.body(List<Entry>)`

splitEntries

true

Only a single entry from the currently being processed feed is set: exchange.in.body(Entry)

splitEntries

false

The entire list of entries from the feed is set: exchange.in.body(List<Entry>)

Camel can set the Feed object on the In header (see feedHeader option to disable this):

Message Headers

Camel atom uses these headers.

Header Description

Header	Description
`CamelAtomFeed`	When consuming the `org.apache.abdera.model.Feed` object is set to this header.

CamelAtomFeed

When consuming the org.apache.abdera.model.Feed object is set to this header.

Samples

In this sample we poll James Strachan’s blog.

from("atom://http://macstrac.blogspot.com/feeds/posts/default").to("seda:feeds");

In this sample we want to filter only good blogs we like to a SEDA queue. The sample also shows how to setup Camel standalone, not running in any Container or using Spring.