Ktor-style Routing DSL

1import io.ktor.server.application.*
2import io.ktor.server.response.*
3import io.ktor.server.routing.*
4import io.ktor.server.request.*
5 
6data class User(val id: Int, val name: String, val email: String)
7 
8fun Application.configureRouting() {
9    routing {
10        route("/api") {
11            get("/users") {
12                val users = listOf(
13                    User(1, "Alice", "alice@example.com"),
14                    User(2, "Bob", "bob@example.com")
15                )
16                call.respond(users)
17            }
18 
19            get("/users/{id}") {
20                val id = call.parameters["id"]?.toIntOrNull()
21                if (id == null) {
22                    call.respondText("Invalid ID", status = HttpStatusCode.BadRequest)
23                    return@get
24                }
25                call.respond(User(id, "User$id", "user$id@example.com"))
26            }
27 
28            post("/users") {
29                val user = call.receive<User>()
30                call.respond(HttpStatusCode.Created, user)
31            }
32        }
33    }
34}