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velocity:templateName[?options]
|
Where templateName is the classpath-local URI of the template to invoke; or the complete URL of the remote template (eg: file://folder/myfile.vm).
You can append query options to the URI in the following format, ?option=value&option=value&...
Options
Option | Default | Description |
---|---|---|
| | Velocity based file loader cache. |
|
| New option in Camel 1.4. : Cache for the resource content when its it is loaded. Is By default, it's |
| | New option in Camel 1.6. : Character encoding of the resource content. |
...
Header | Description |
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| Camel 1.x: The resource as an |
| Camel 1.x: The templateName as a |
| Camel 2.0: The resource as an |
| Camel 2.0: The templateName as a |
In Camel 1.4 headers set during the velocity Velocity evaluation is are returned to the message and added as headers. Then its kinda possible to return values from Velocity to the Message.
An example: Set For example, to set the header value of fruit
in the Velocity template .tm
:
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$in.setHeader('fruit', 'Apple') |
The fruit
header 'fruit' is now accessible from the message.out.headers
.
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Camel will provide exchange information in the Velocity context (just a Map
). The Exchange
is transfered as:
key | value |
---|---|
| The |
| The headers of the in In message. |
| The Camel Context intance. |
| The in In message. |
| The in In message. |
| The in In message body. |
| The out Out message (only for InOut message exchange pattern). |
| The out Out message (only for InOut message exchange pattern). |
Hot reloading
The velocity Velocity template resource is, by default, hot reloadable for both file and classpath resources (expanded jar). Setting the If you set contentCache=true
then , Camel will only load the resource once, and thus hot reloading is not possible. This scenario can be used in production usage , when the resource never changes.
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from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"); |
To use a velocity Velocity template to formulate a response for to 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 the following route:
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from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"). to("activemq:Another.Queue"); |
And to use the content cache, ege.g. for use in production usage , where the .vm
template never changes:
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from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm?contentCache=true"). to("activemq:Another.Queue"); |
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In this sample we want to use Velocity as templating for an order confirmation email. The email template is laid out in Velocity as:
...