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Chapter 86. Jolt

JOLT Component

Available as of Camel 2.16
The Jolt component allows you to process a JSON messages using an JOLT specification. This can be ideal when doing JSON to JSON transformation.
Maven users will need to add the following dependency to their pom.xml for this component: 
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-jolt</artifactId>
    <version>2.17.0.redhat-630xxx</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

jolt:specName[?options]
Where specName is the classpath-local URI of the specification to invoke; or the complete URL of the remote specification (eg: file://folder/myfile.json).
You can append query options to the URI in the following format, ?option=value&option=value&...

Options

Option
Default
Description
allowContextMapAll (producer)
false
Sets whether the context map should allow access to all details. By default only the message body and headers can be accessed. This option can be enabled for full access to the current Exchange and CamelContext. Doing so imposes a potential security risk as this opens access to the full power of CamelContext API.
allowTemplateFromHeader (producer)
false
Whether to allow to use resource template from header or not (default false). Enabling this option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution.
contentCache
true
Cache for the resource content when it is loaded. Note : as of Camel 2.9 cached resource content can be cleared via JMX using the endpoint's clearContentCache operation.
outputType
Hydrated
Sets the output of the transformation to Hydrated as List or Maps, or JsonString as a String object containing the JSON.
inputType
Hydrated
Sets the input of the transformation to Hydrated as List or Maps, or JsonString as a String object containing the JSON.
transformDsl
Chainr
The transform DSL to use for loading the provided specification. Available values Chainr, Shiftr, Defaultr, Removr and Sortr.

Dynamic specification

Camel provides a header by which you can define a different resource location for a specification. If this header is set then Camel uses this over the endpoint configured resource. This allows you to provide a dynamic specification at runtime.
Header
Type
Description
CamelJoltResourceUri
String
A URI for the specification resource to use instead of the endpoint configured.

Samples

For example you could use something like 
from("activemq:My.Queue").
  to("jolt:com/acme/MyResponse.json");
And a file based resource: 
from("activemq:My.Queue").
  to("jolt:file://myfolder/MyResponse.json?contentCache=true").
  to("activemq:Another.Queue");
You can also specify what specification the component should use dynamically via a header, so for example: 
from("direct:in").
  setHeader("CamelJoltResourceUri").constant("path/to/my/spec.json").
  to("jolt:dummy?allowTemplateFromHeader=true");
Warning
Enabling the allowTemplateFromHeader option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution.