Routing requests

Now, let’s examine the routing block more closely:

routing {
    get("/") {
        call.respondText("Hello World!")
    }
}

This block defines all the URLs that our server will handle. Currently, it only manages the root URL. When this URL is requested, the server returns a text response, “OK”, to the user.

Next, we explore how to return a JSON response:

get("/status") {
    call.respond(mapOf("status" to "OK"))
}

Instead of the respondText() method, we use respond(), which accepts an object rather than a string. In this example, we pass a map of strings. However, running this code as is will cause an exception, as objects aren’t automatically serialized into JSON. We can overcome this by using the kotlinx-serialization and ktor-server-content-negotiation libraries. We begin by adding them to our dependencies:

dependencies {
    ...
    implementation("io...