Reading boolean response body

[Poliana Belo]

Hello! I know very little about gatling and scala....and actualy I'm trying to read the response body of a request and i dont know how to do it with a boolean response. I found out how to read a Json only. Is it possible? 

A part of my code:

val test = scenario("Simulation")

.exec(http("request_0")

.post("/test/message")

.headers(headers_0)

.body(StringBody("""{ "k": "2C04A2", "d": "00010B901080f000f00000", "t": """ + System.currentTimeMillis + """ }""")).asJSON

.check(regex(true).find(0).exists))