class DemoApplication {
    static void main(String[] args) {
        SpringApplication.run DemoApplication, args
    }
    @PostMapping("/")
    String greet(@RequestBody Greeting greeting) {
        return "Hello ${greeting.name}, with email ${greeting.email}"
    }
}

@JsonInclude(JsonInclude.Include.NON_NULL)
class Greeting {
  String name
  String email
}

class DemoApplication {
    static void main(String[] args) {
        SpringApplication.run DemoApplication, args
    }
    @PostMapping("/")
    String greet(@RequestBody Greeting greeting) {
        return "Hello ${greeting.name}, with email ${greeting.email}"
    }
}

class Greeting {
  String name
  String email
}

~ curl -H "Content-Type: application/json" -X POST localhost:8080
{"timestamp":"2018-04-22T21:18:39.849+0000","status":400,"error":"Bad Request","message":"Required request body is missing: public java.lang.String com.example.demo.DemoApplication.greet(com.example.demo.Greeting)","path":"/"}
~ curl -H "Content-Type: application/json" -X POST localhost:8080  -d '{}'
Hello null, with email null
~ curl -H "Content-Type: application/json" -X POST localhost:8080  -d '{"name": "AlejoDev"}'
Hello AlejoDev, with email null
~ curl -H "Content-Type: application/json" -X POST localhost:8080  -d '{"name": "AlejoDev", "email":"info@alejodev.com"}'
Hello AlejoDev, with email info@alejodev.com

~ curl -H "Content-Type: application/json" -X POST localhost:8080  -d '{"name": "AlejoDev"}'