i working apache nifi 0.5.1 on groovy script replace incoming json values ones contained in mapping file. mapping file looks (it simple .txt): header1;header2;header3 a;some text;a2 i have started following: import groovy.json.jsonbuilder import groovy.json.jsonslurper import java.nio.charset.standardcharsets def flowfile = session.get(); if (flowfile == null) { return; } flowfile = session.write(flowfile, { inputstream, outputstream -> def content = """ { "field1": "a" "field2": "a", "field3": "a" }""" def slurped = new jsonslurper().parsetext(content) def builder = new jsonbuilder(slurped) builder.content.field1 = "a" builder.content.field2 = "some text" builder.content.field3 = "a2" outputstream.write(builder.toprettystring().ge...