Atom Component

Table of Contents

URI format
Options
Exchange data format
Message Headers
Samples
See Also

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 component supports 28 endpoint options which are listed below:

{% raw %}

Name	Group	Default	Java Type	Description
feedUri	consumer		`String`	Required The URI to the feed to poll.
bridgeErrorHandler	consumer	`false`	`boolean`	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.
feedHeader	consumer	`true`	`boolean`	Sets whether to add the feed object as a header
filter	consumer	`true`	`boolean`	Sets whether to use filtering or not of the entries.
lastUpdate	consumer		`Date`	Sets the timestamp to be used for filtering entries from the atom feeds. This options is only in conjunction with the splitEntries.
password	consumer		`String`	Sets the password to be used for basic authentication when polling from a HTTP feed
sendEmptyMessageWhenIdle	consumer	`false`	`boolean`	If the polling consumer did not poll any files you can enable this option to send an empty message (no body) instead.
sortEntries	consumer	`false`	`boolean`	Sets whether to sort entries by published date. Only works when splitEntries = true.
splitEntries	consumer	`true`	`boolean`	Sets whether or not entries should be sent individually or whether the entire feed should be sent as a single message
throttleEntries	consumer	`true`	`boolean`	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.
username	consumer		`String`	Sets the username to be used for basic authentication when polling from a HTTP feed
exceptionHandler	consumer (advanced)		`ExceptionHandler`	To let the consumer use a custom ExceptionHandler. Notice 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.
exchangePattern	consumer (advanced)		`ExchangePattern`	Sets the exchange pattern when the consumer creates an exchange.
pollStrategy	consumer (advanced)		`PollingConsumerPollStrategy`	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.
synchronous	advanced	`false`	`boolean`	Sets whether synchronous processing should be strictly used or Camel is allowed to use asynchronous processing (if supported).
backoffErrorThreshold	scheduler		`int`	The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.
backoffIdleThreshold	scheduler		`int`	The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.
backoffMultiplier	scheduler		`int`	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.
delay	scheduler	`500`	`long`	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).
greedy	scheduler	`false`	`boolean`	If greedy is enabled then the ScheduledPollConsumer will run immediately again if the previous run polled 1 or more messages.
initialDelay	scheduler	`1000`	`long`	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).
runLoggingLevel	scheduler	`TRACE`	`LoggingLevel`	The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.
scheduledExecutorService	scheduler		`ScheduledExecutorService`	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`	`ScheduledPollConsumerScheduler`	To use a cron scheduler from either camel-spring or camel-quartz2 component
schedulerProperties	scheduler		`Map`	To configure additional properties when using a custom scheduler or any of the Quartz2 Spring based scheduler.
startScheduler	scheduler	`true`	`boolean`	Whether the scheduler should be auto started.
timeUnit	scheduler	`MILLISECONDS`	`TimeUnit`	Time unit for initialDelay and delay options.
useFixedDelay	scheduler	`true`	`boolean`	Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

{% endraw %}

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
`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
`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.