json to json conversion by ExecuteScript processor - groovy

Question

I have following json data and i want to convert data in expected result by ExecuteScript nifi processor
{
"time": "2017-01-01T01:14:55+00:00",
"any": {
"nested": "data"
}
}
expected Result
{
"time": 1483233295,
"any": {
"nested": "data"
}
}
I am using following groovy code but getting some error please help to find the solution
var 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");
flowFile = session.write(flowFile, new
StreamCallback(function(inputStream, outputStream) {
var inputJSON = IOUtils.toString(inputStream,StandardCharsets.UTF_8);
var contentObj = JSON.parse(inputJSON);
contentObj.time = flowFile.getAttribute("timestamp");
outputStream.write(JSON.stringify(contentObj).getBytes(StandardCharsets.UTF_8));
}));
session.transfer(flowFile, REL_SUCCESS);
}
getting error
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
/home/jdoodle.groovy: 8: unable to resolve class StreamCallback
# line 8, column 36.
flowFile = session.write(flowFile, new
^
1 error

Answer 1

use ExecuteGroovyScript processor (it's optimized for groovy lang) with this kind of code:
import groovy.json.JsonSlurper
import groovy.json.JsonBuilder
def flowFile = session.get()
if (!flowFile) return
flowFile.write{rawIn, rawOut->
def json = rawIn.withReader("UTF-8"){ r-> new JsonSlurper().parse(r) }
json.time = Date.parse("yyyy-MM-dd'T'HH:mm:ssX", json.time).getTime()/1000
rawOut.withWriter("UTF-8"){ w-> new JsonBuilder(json).writeTo(w) }
}
REL_SUCCESS << flowFile
this code converts format of the field time with Date format to unix epoch time inside json content of flowfile.