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This page is outdated, for the current version see: https://github.com/apache/camel/blob/master/components/camel-rss/src/main/docs/rss-component.adoc


RSS Component

The rss: component is used for polling RSS feeds. Camel will default poll the feed every 60th seconds.

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

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

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

New in Camel 2.0Camel-rss internally uses a patched version of ROME hosted on ServiceMix to solve some OSGi class loading issues.

URI format

...

...

rss:rssUri

...

Where rssUri is the URI to the RSS feed to poll.

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

Options

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Property

Default

Description

splitEntries

true

If true, Camel will poll the feed and for the subsequent polls return each entry splits a feed into its individual entries and returns each entry, poll by poll. If the For example, if a feed contains 7 seven entries then , Camel will return returns the first entry on the first poll, the 2nd second entry on the next second poll, until and so on. When no more entries where as Camel will do a new update on the are left in the feed, Camel contacts the remote RSS URI to obtain a new feed. If false then , Camel will poll obtains a fresh feed on every invocationpoll and returns all of the feed's entries.

filter

true

Is only used by the split entries to filter the entries to return. Camel will default use the UpdateDateFilter that only return Use in combination with the splitEntries option in order to filter returned entries. By default, Camel applies the UpdateDateFilter filter, which returns only new entries from the feed. So the client consuming from the feed never receives the same , ensuring that the consumer endpoint never receives an entry more than once. The filter will return orders the entries ordered by chronologically, with the newest returned last.

throttleEntries

true

Camel 2.5: 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 is set to true.

lastUpdate

null

Is only used by the filter, as the starting timestamp for selection never entries Use in combination with the filter option to block entries earlier than a specific date/time (uses the entry.updated timestamp). Syntax The format is: yyyy-MM-ddTHH:MM:ss. Example: 2007-12-24T17:45:59.

feedHeader

true

Sets Specifies whether to add the ROME SyndFeed object as a header.

sortEntries

false

If splitEntries is true, this specifies whether to sort the entries by updated date.

consumer.delay

60000

Delay in millis milliseconds between each poll.

consumer.initialDelay

1000

Millis Milliseconds before polling starts.

consumer.userFixedDelay

false

Set to true to use fixed delay between pools, otherwise fixed rate is used. See ScheduledExecutorService in JDK for details.

username Camel 2.16: For basic authentication when polling from a HTTP feed
password Camel 2.16: For basic authentication when polling from a HTTP feed

Exchange data types

Camel will set initializes the in In body on the returned Exchange with a ROME SyndFeed. Depending on the value of the splitEntries flag, Camel will returns either return a SyndFeed with one SyndEntry or a java.util.List of SyndEntrys.

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Option

Value

Behavior

splitEntries

true

Only a A single entry from the currently being processed current feed is set in the new exchange feed.

splitEntries

false

The entires entire list of entries from the current feed is set in the new exchange feed.

Camel can also set the entire SyndFeed object on the in header (see feedHeader option above to disable):

...

Message Headers

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Header

Description

CamelRssFeed

The entire SyncFeed object.

...

RSS Dataformat

The RSS component ships with an RSS dataformat that can be used to convert between String (as XML) and ROME RSS model objects.

  • marshal = from ROME SyndFeed to XML String
  • unmarshal = from XML String to ROME SyndFeed

A route using this would look something like this:

...

{snippet:id=ex|lang=java|url=

...

camel/trunk/components/camel-rss/src/test/java/org/apache/camel/dataformat/rss/RssDataFormatTest.java}

...

The idea purpose of this feature is to be able make it possible to use Camel's lovely built-in expressions for manipulating RSS messages. As shown below, an XPath expression can be used to filter the RSS message:

...

{snippet:id=ex|lang=java|url=

...

camel/trunk/components/camel-rss/src/test/java/org/apache/camel/dataformat/rss/RssFilterWithXPathTest.java}

...

Query parameters

If the URL for the RSS feed uses query parameters, this component will understand them as well, for example if the feed uses alt=rss, then you can for example do
from("rss:http://someserver.com/feeds/posts/default?alt=rss&splitEntries=false&consumer.delay=1000").to("bean:rss");

Filtering entries

You can filter out entries quite easily using XPath, as shown in the data format section above. You can also exploit Camel's Bean Integration to implement your own conditions. For instance, a filter equivalent to the XPath example above would be:{snippet:id=ex1|lang=java|url=camel/trunk/components/camel-rss/src/test/java/org/apache/camel/component/rss/RssFilterTest.java}The custom bean for this would be:{snippet:id=ex2|lang=java|url=camel/trunk/components/camel-rss/src/test/java/org/apache/camel/component/rss/RssFilterTest.java}Endpoint See Also

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