JSON to JSON transformation policy

Phases

V3 engine

onRequestContent	onResponseContent
X	X

V4 engine

onRequest	onResponse	onMessageRequest	onMessageResponse
X	X	X	X

Description

You can use the json-to-json policy to apply a transformation (or mapping) on the request and/or response and/or message content.

This policy is based on the JOLT library.

In APIM, you need to provide the JOLT specification in the policy configuration.

Note	You can use APIM EL in the JOLT specification.

At request/response level, the policy will do nothing if the processed request/response does not contain JSON. This policy checks the Content-Type header before applying any transformation.

At message level, the policy will do nothing if the processed message has no content. It means that the message will be re-emitted as is.

Compatibility with APIM

Plugin version	APIM version
1.x	Up to 3.19.x
2.x	3.20.x
3.x	4.x to latest

Configuration

You can configure the policy with the following options:

Property	Required	Description	Type	Default
scope	only for v3 engine	The execution scope (request or response)	string	REQUEST
specification	X	The JOLT specification to apply on a given content. Can contains EL.	string
overrideContentType		Override the Content-Type to application/json.	string	true

Example configuration:

{
    "json-to-json": {
        "scope": "REQUEST",
        "specification": "[{ \"operation\": \"shift\", \"spec\": { \"_id\": \"id\", \"*\": { \"$\": \"&1\" } } }, { \"operation\": \"remove\", \"spec\": { \"__v\": \"\" } }]"
    }
}

Examples

For this input:

Input

{
    "_id": "57762dc6ab7d620000000001",
    "name": "name",
    "__v": 0
}

And this JOLT specification:

[
  {
    "operation": "shift",
    "spec": {
      "_id": "id",
      "*": {
        "$": "&1"
      }
    }
  },
  {
    "operation": "remove",
    "spec": {
      "__v": ""
    }
  }
]

The output is as follows:

{
    "id": "57762dc6ab7d620000000001",
    "name": "name"
}

Errors

V3 engine

Code	Message
500	Bad specification file or transformation cannot be executed properly

V4 engine

Phase	Code	Error template key	Description
*	500	INVALID_JSON_TRANSFORMATION	Unable to apply JOLT transformation to payload