JSON to JSON Policy

Apply a transformation (or mapping) on the request or response content.

This policy is based on the JOLT library.

You must provide the JOLT specification in the policy configuration.

note

You can use Expression Language in the JOLT specification.

At the 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.

Timing

On Request Content	On Response Content
X	X

Configuration

Property	Required	Description	Type	Default
scope	yes	The execution scope (REQUEST or RESPONSE)	string	REQUEST
specification	yes	The JOLT specification to apply on a given content. Can contain expression language.	string
overrideContentType	no	Override the Content-Type to application/json.	string	true

Example

JSON input:

{
  "StudentDatabase": {
    "student": [
      {
        "name": "Alice Johnson",
        "age": 20,
        "major": "Computer-Science",
        "student_id": "S123456",
        "gpa": 4.8
      },
      {
        "name": "Bob Smith",
        "age": 22,
        "major": "Literature",
        "student_id": "S654321",
        "gpa": 4.2
      },
      {
        "name": "Charlie Brown",
        "age": 21,
        "major": "Computer-Science",
        "student_id": "S789012",
        "gpa": 4.5
      }
    ]
  }
}

JSON to JSON policy configuration:

// Shift operation to restructure the JSON data
[
  {
    "operation": "shift",
    "spec": {
      "StudentDatabase": {
        "student": {
          // Shift has a precedence order when matching, so the "*" will match "last".
          "*": {
            // Map each student's name to a new array 'student names' and keep it in 'students'
            "name": ["student names[]", "students[&1].name"],
            // Keep the major,student_id,age and gpa in the 'students' array
            //&1 is a reference used within the shift operation to refer back to the matched index or key at the current level of the JSON structure
            "major": "students[&1].major",
            "student_id": "students[&1].student_id",
            "age": "students[&1].age",
            "gpa": "students[&1].gpa"
          }
        }
      }
    }
  },
  {
    // Remove operation to delete the 'age' and 'gpa' field from each student object
    "operation": "remove",
    "spec": {
      "students": {
        "*": {
          "age": "",
          "gpa": ""
        }
      }
    }
  }
]

Expected output:

{
    "student names": [
        "Alice Johnson",
        "Bob Smith",
        "Charlie Brown"
    ],
    "students": [
        {
            "name": "Alice Johnson",
            "major": "Computer-Science",
            "student_id": "S123456"
        },
        {
            "name": "Bob Smith",
            "major": "Literature",
            "student_id": "S654321"
        },
        {
            "name": "Charlie Brown",
            "major": "Computer-Science",
            "student_id": "S789012"
        }
    ]
}

Errors

Code	Description
500	Bad specification file or transformation cannot be executed properly.