external.gradle

buildscript {
  repositories {
    jcenter()
  }
  dependencies {
    classpath "com.squareup.okhttp3:okhttp:3.2.0"
  }
}

import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.Response

import groovy.json.*

task okHttp << {
  def client = new OkHttpClient()
  def request = new Request.Builder()
        .url("https://api.github.com")
        .build()
  def response = client.newCall(request).execute()
  def body = response.body().string()

  println body
  println JsonOutput.prettyPrint(body)

  def slurper = new JsonSlurper()

  def parsed = slurper.parseText(body)

  println parsed.emojis_url

  def emoReq = new Request.Builder().url(parsed.emojis_url).build()

  def emoRes = client.newCall(emoReq).execute()
  def emoBody = emoRes.body().string()

  println JsonOutput.prettyPrint(emoBody)
}