Make use of new GetMapping and PostMapping annotations

Closes gh-5277

spring-boot-samples/spring-boot-sample-web-groovy-templates/src/main/java/sample/groovytemplates/mvc/MessageController.java

@@ -28,10 +28,11 @@ import org.springframework.stereotype.Controller;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.FieldError;
 import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.servlet.ModelAndView;
 import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 
@@ -45,23 +46,23 @@ public class MessageController {
 		this.messageRepository = messageRepository;
 	}
 
-	@RequestMapping
+	@GetMapping
 	public ModelAndView list() {
 		Iterable<Message> messages = this.messageRepository.findAll();
 		return new ModelAndView("messages/list", "messages", messages);
 	}
 
-	@RequestMapping("{id}")
+	@GetMapping("{id}")
 	public ModelAndView view(@PathVariable("id") Message message) {
 		return new ModelAndView("messages/view", "message", message);
 	}
 
-	@RequestMapping(params = "form", method = RequestMethod.GET)
+	@GetMapping(params = "form")
 	public String createForm(@ModelAttribute Message message) {
 		return "messages/form";
 	}
 
-	@RequestMapping(method = RequestMethod.POST)
+	@PostMapping
 	public ModelAndView create(@Valid Message message, BindingResult result,
 			RedirectAttributes redirect) {
 		if (result.hasErrors()) {