THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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MVEL
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Component
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Available
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as
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of
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Camel
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2.12
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The
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mvel:
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component
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allows
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you
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to
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process
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a
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message
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using
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an
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template.
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This
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can
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be
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ideal
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when
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using
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to
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generate
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responses
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for
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requests.
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Maven
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users
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will
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need
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to
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add
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the
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following
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dependency
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to
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their
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pom.xml
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for
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this
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component:
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{code:xml}
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-mvel</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
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URI format
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{code} h3. URI format {code} mvel:templateName[?options] {code} Where *templateName* is the |
Where templateName is the classpath-local
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URI
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of
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the
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template
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to
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invoke;
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or
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the
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complete
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URL
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of
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the
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remote
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template
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(eg:
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You
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can
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append
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query
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options
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to
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the
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URI
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in
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the
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following
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format,
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?option=value&option=value&...
Options
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Message Headers
The mvel component sets a couple headers on the message.
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MVEL Context
Camel will provide exchange information in the MVEL context (just a Map). The Exchange is transfered as:
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Hot reloading
The mvel template resource is, by default, hot reloadable for both file and classpath resources (expanded jar). If you set contentCache=true, Camel will only load the resource once, and thus hot reloading is not possible. This scenario can be used in production, when the resource never changes.
Dynamic templates
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.
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Samples
For example you could use something like
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}} h3. Options {div:class=confluenceTableSmall} || Option || Default || Description || | {{contentCache}} | {{true}} | Cache for the resource content when it is loaded. The cached resource content can be cleared via JMX using the endpoint's {{clearContentCache}} operation. | | {{encoding}} | {{null}} | Character encoding of the resource content. | {div} h3. Message Headers The mvel component sets a couple headers on the message. {div:class=confluenceTableSmall} || Header || Description || | {{CamelMvelResourceUri}} | The *templateName* as a {{String}} object. | {div} h3. MVEL Context Camel will provide exchange information in the MVEL context (just a {{Map}}). The {{Exchange}} is transfered as: {div:class=confluenceTableSmall} || key || value || | {{exchange}} | The {{Exchange}} itself. | | {{exchange.properties}} | The {{Exchange}} properties. | | {{headers}} | The headers of the In message. | | {{camelContext}} | The Camel Context intance. | | {{request}} | The In message. | | {{in}} | The In message. | | {{body}} | The In message body. | | {{out}} | The Out message (only for InOut message exchange pattern). | | {{response}} | The Out message (only for InOut message exchange pattern). | {div} h3. Hot reloading The mvel template resource is, by default, hot reloadable for both file and classpath resources (expanded jar). If you set {{contentCache=true}}, Camel will only load the resource once, and thus hot reloading is not possible. This scenario can be used in production, when the resource never changes. h3. Dynamic templates 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. {div:class=confluenceTableSmall} || Header || Type || Description || | CamelMvelResourceUri | String | A URI for the template resource to use instead of the endpoint configured. | | CamelMvelTemplate | String | The template to use instead of the endpoint configured. | {div} h3. Samples For example you could use something like {code} from("activemq:My.Queue"). to("mvel:com/acme/MyResponse.mvel"); {code} |
To
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use
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a
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MVEL
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template
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to
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formulate
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a
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response
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to
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a
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message
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for
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InOut
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message
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exchanges
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(where
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there
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is
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a
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JMSReplyTo
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header).
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To
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specify
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what
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template
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the
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component
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should
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use
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dynamically
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via
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a
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header,
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so
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for
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example:
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} from("direct:in"). setHeader("CamelMvelResourceUri").constant("path/to/my/template.mvel"). to("mvel:dummy"); {code} |
To
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specify
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a
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template
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directly
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as
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a
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header
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the
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component
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should
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use
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dynamically
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via
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a
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header,
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so
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for
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example:
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} from("direct:in"). setHeader("CamelMvelTemplate").constant("@{\"The result is \" + request.body * 3}\" }"). to("velocity:dummy"); {code} {include:Endpoint See Also} |
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