Let's start with creating a simple REST service returning a welcome message:
@RestController class BasicController { @GetMapping("/welcome") fun welcome() = "Hello World" }
A comparable Java method is shown as follows. A major difference is how we are able to define a function in one line in Kotlin--fun welcome() = "Hello World":
@GetMapping("/welcome") public String welcome() { return "Hello World"; }
If we run FirstWebServiceWithKotlinApplication.kt as a Kotlin application, it will start up the embedded Tomcat container. We can launch up the URL (http://localhost:8080/welcome) in the browser, as shown in the following screenshot:
