Jackson + Kotlin makes easy work with JSON.

Test.kt

import com.fasterxml.jackson.databind.JsonNode
import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper

/**
 *
 *
 * Date: 2019-03-05
 * Time: 11:03 AM
 * @author jerieljan
 */
fun main() {

    //Feed sample JSON
    val json = "{\n  \"product\": {\n    \"name\" : \"Test Product\",\n    \"description\": \"A test product\",\n    \"pricing\": {\n      \"TestProduct-1\": {\n        \"sku\": \"TestProduct-1\",\n        \"price\": \"100\",\n        \"currency\": \"USD\",\n        \"rate\": \"Hourly\"\n      }\n    }\n  }\n}";

    //Use Jackson to load the JSON tree.
    val mapper = jacksonObjectMapper()
    val parsed = mapper.readTree(json)

    //Extract values by bracket notation
    val productName = parsed["product"]["name"] ?: "No name"
    val productDescription = parsed["product"]["description"] ?: "No description"

    //Since it's all in strings (effectively), it's also okay to concatenate values together.
    val price = "${parsed["product"]["pricing"].first()["currency"]} ${parsed["product"]["pricing"].first()["price"]}"

    //You can even do it the classic way of chaining gets.
    val productSku = parsed.get("product")?.get("name")?.get("sku")?.toString() ?: "No SKU"


    // Let's try printing.
    // Print the product.
    println("Printing Basic Values")
    println("$productName - $productDescription - $productSku")
    println("Price: $price")
    println()


    //Let's try using a data class / POJO object instead
    val testProduct = Product(parsed)

    //Print the product.
    println("Printing Data Class")
    println("Name: ${testProduct.name} Description: ${testProduct.description}")
    println()

    println("Printing Data Class' built-in toString()")
    println(testProduct)
    println()

}

data class Product(private val model: JsonNode,
                   val name: String = model["product"]["name"]?.toString() ?: "No name",
                   val description: String = model["product"]["description"]?.toString() ?: "No description",
                   val sku: String = model["product"]["name"]["sku"]?.toString() ?: "No SKU",
                   val price: String = "${model["product"]["pricing"].first()["currency"]} ${model["product"]["pricing"].first()["price"]}")