vaderSentGroovy.groovy

import java.nio.charset.StandardCharsets
import org.apache.commons.io.IOUtils
import org.apache.nifi.processor.io.StreamCallback
import groovy.transform.ToString
import com.vader.SentimentAnalyzer
import groovy.json.JsonBuilder
import groovy.json.JsonOutput
import groovy.json.JsonSlurper

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

flowFile=session.write(flowFile,{inputStream, outputStream ->

		// ---------------PART ONE------------------
    def jsonString = IOUtils.toString(inputStream, StandardCharsets.UTF_8) // Json String
    def original=new JsonSlurper().parseText(jsonString) // JSON object 
	def tweetText= original.text  // Gets text of tweet
		// Puts text into Sentiment Analyzer

		// ---------------PART TWO------------------
	SentimentAnalyzer sentimentAnalyzer=new SentimentAnalyzer(tweetText)
	sentimentAnalyzer.analyse()
	def map=sentimentAnalyzer.getPolarity()

	// Gets each of the scores
	def posValue=map['positive']		
	def negValue=map['negative']
	def neuValue=map['neutral']
	def compValue=map['compound']

	// Converts them to string
	def pos=posValue.toString()	
	def neg=negValue.toString()
	def neu=neuValue.toString()
	def comp=compValue.toString()

		// ---------------PART THREE------------------
	// Creates second Json
	def sentimentScore =new JsonBuilder() 
	def root=sentimentScore pos: pos, neg:neg, neu:neu,comp:comp, tweetText: tweetText
	
	// concatentates both jsons
	def finalPart=JsonOutput.toJson([original: original, sentimentScore: sentimentScore]) 
    outputStream.write(finalPart.toString().getBytes(StandardCharsets.UTF_8))

	} as StreamCallback)

// Successful transfer and exit
session.transfer(flowFile, REL_SUCCESS)