ProductRestApplication.kt

package com.example.productrest

import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RestController

@SpringBootApplication
open class ProductRestApplication

@RestController
internal class MyProductController {
    @GetMapping("/products")
    fun getproducts()= listOf("Windows phone", "blackberry")

}

fun main(args: Array<String>) {
    SpringApplication.run(ProductRestApplication::class.java, *args)
}