I am trying to run an ExecuteScript that should be taking in a json message and parsing the fields for further processing but I cannot get this to work. I ran a tester for ExecuteScript created by this author: https://funnifi.blogspot.com/2016/06/testing-executescript-processor-scripts.html And it returned the following error: cannot create an instance from the abstract interface org.apache.nifi.processor.io.StreamCallback I do not see the error in the script so could someone please assist with this: flowFile = session.get(); if (flowFile != null) { var StreamCallback = Java.type("org.apache.nifi.processor.io.StreamCallback"); var IOUtils = Java.type("org.apache.commons.io.IOUtils"); var StandardCharsets = Java.type("java.nio.charset.StandardCharsets"); var transformed_message = {}; var error = false; var line = "ops_track"; // Get attributes flowFile = session.write(flowFile, new StreamCallback(function (inputStream, outputStream) { // Read input FlowFile content var content = IOUtils.toString(inputStream, StandardCharsets.UTF_8); // message or content var message_content = {}; try { message_content = JSON.parse(content); transformed_message.postID = (((message_content || {}).postID || "null")); transformed_message.contentType = (((message_content || {}).contentType || "null")); transformed_message.published = (((message_content || {}).published || "null")); transformed_message.crawled = (((message_content || {}).crawled || "null")); transformed_message.providerID = (((message_content || {}).providerID || "null")); line = line + " " + "postID=" + transformed_message.postID + "," + "contentType=" + transformed_message.contentType + "," + "published=" + transformed_message.published + "," + "crawled=" + transformed_message.crawled + "," + "providerID=" + transformed_message.providerID + "," + " value=" + "1" + " " + time * 1000000 + "\n"; // Write output content if (transformed_message) { outputStream.write(line.getBytes(StandardCharsets.UTF_8)); } } catch (e) { error = true; outputStream.write(content.getBytes(StandardCharsets.UTF_8)); } })); if (error) { session.transfer(flowFile, REL_FAILURE) } else { session.transfer(flowFile, REL_SUCCESS) } } ... View more