Hands-On Microservices with Kotlin

Answering a GET request

According to our definition, initially, when we get a GET request for a resource we should answer with the resource and a 200 OK or with 404 NOT FOUND if the resource is not found.

So, we can modify our method:

@GetMapping(value = "/customer/{id}")fun getCustomer(@PathVariable id: Int): ResponseEntity<Customer?> {  val customer = customerService.getCustomer(id)  val status = if (customer == null) HttpStatus.NOT_FOUND else HttpStatus.OK  return ResponseEntity(customer, status)}

First, we get the customer; if the customer is not found, the service will return null, so we can set our status to 404 NOT FOUND or 200 OK.