XmlToJson.groovy

import org.apache.commons.io.IOUtils
import java.nio.charset.*
import org.json.JSONObject;
import org.json.XML;

def flowFile = session.get()
if (!flowFile) return

flowFile = session.write(flowFile,
    { inputStream, outputStream ->
        def text = IOUtils.toString(inputStream, StandardCharsets.UTF_8)
        def xmlJSONObj = XML.toJSONObject(text);
        def json = xmlJSONObj.toString();
        outputStream.write(json.getBytes(StandardCharsets.UTF_8))
    } as StreamCallback)

flowFile = session.putAttribute(flowFile, "mime.type", "application/json")
session.transfer(flowFile, ExecuteScript.REL_SUCCESS)