Chapter 61. Chunk Component
Available as of Camel version 2.15
The chunk: component allows for processing a message using a Chunk template. This can be ideal when using Templating to generate responses for requests.
Maven users will need to add the following dependency to their pom.xml
for this component:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-chunk</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-chunk</artifactId>
<version>x.x.x</version> <!-- use the same version as your Camel core version -->
</dependency>
61.1. URI format Copy linkLink copied to clipboard!
chunk:templateName[?options]
chunk:templateName[?options]
Where templateName is the classpath-local URI of the template to invoke.
You can append query options to the URI in the following format, ?option=value&option=value&…
61.2. Options Copy linkLink copied to clipboard!
The Chunk component has no options.
The Chunk endpoint is configured using URI syntax:
chunk:resourceUri
chunk:resourceUri
with the following path and query parameters:
61.2.1. Path Parameters (1 parameters): Copy linkLink copied to clipboard!
Name | Description | Default | Type |
---|---|---|---|
resourceUri | Required Path to the resource. You can prefix with: classpath, file, http, ref, or bean. classpath, file and http loads the resource using these protocols (classpath is default). ref will lookup the resource in the registry. bean will call a method on a bean to be used as the resource. For bean you can specify the method name after dot, eg bean:myBean.myMethod. | String |
61.2.2. Query Parameters (7 parameters): Copy linkLink copied to clipboard!
Name | Description | Default | Type |
---|---|---|---|
contentCache (producer) | Sets whether to use resource content cache or not | false | boolean |
encoding (producer) | Define the encoding of the body | String | |
extension (producer) | Define the file extension of the template | String | |
themeFolder (producer) | Define the themes folder to scan | String | |
themeLayer (producer) | Define the theme layer to elaborate | String | |
themeSubfolder (producer) | Define the themes subfolder to scan | String | |
synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
Chunk component will look for a specific template in themes folder with extensions .chtml or _.cxml. _If you need to specify a different folder or extensions, you will need to use the specific options listed above.
61.3. Chunk Context Copy linkLink copied to clipboard!
Camel will provide exchange information in the Chunk context (just a Map
). The Exchange
is transferred as:
key | value |
---|---|
|
The |
|
The |
| The headers of the In message. |
| The Camel Context. |
| The In message. |
| The In message body. |
| The Out message (only for InOut message exchange pattern). |
61.4. Dynamic templates Copy linkLink copied to clipboard!
Camel provides two headers by which you can define a different resource location for a template or the template content itself. If any of these headers is set then Camel uses this over the endpoint configured resource. This allows you to provide a dynamic template at runtime.
Header | Type | Description | Support Version |
---|---|---|---|
ChunkConstants.CHUNK_RESOURCE_URI | String | A URI for the template resource to use instead of the endpoint configured. | |
ChunkConstants.CHUNK_TEMPLATE | String | The template to use instead of the endpoint configured. |
61.5. Samples Copy linkLink copied to clipboard!
For example you could use something like:
from("activemq:My.Queue"). to("chunk:template");
from("activemq:My.Queue").
to("chunk:template");
To use a Chunk template to formulate a response for a message for InOut message exchanges (where there is a JMSReplyTo
header).
If you want to use InOnly and consume the message and send it to another destination you could use:
from("activemq:My.Queue"). to("chunk:template"). to("activemq:Another.Queue");
from("activemq:My.Queue").
to("chunk:template").
to("activemq:Another.Queue");
It’s possible to specify what template the component should use dynamically via a header, so for example:
from("direct:in"). setHeader(ChunkConstants.CHUNK_RESOURCE_URI).constant("template"). to("chunk:dummy");
from("direct:in").
setHeader(ChunkConstants.CHUNK_RESOURCE_URI).constant("template").
to("chunk:dummy");
An example of Chunk component options use:
from("direct:in"). to("chunk:file_example?themeFolder=template&themeSubfolder=subfolder&extension=chunk");
from("direct:in").
to("chunk:file_example?themeFolder=template&themeSubfolder=subfolder&extension=chunk");
In this example Chunk component will look for the file file_example.chunk in the folder template/subfolder.
61.6. The Email Sample Copy linkLink copied to clipboard!
In this sample we want to use Chunk templating for an order confirmation email. The email template is laid out in Chunk as:
61.7. See Also Copy linkLink copied to clipboard!
- Configuring Camel
- Component
- Endpoint
- Getting Started