Add request method constraints to some request mappings

Some request mappings that were only intended to handle GET requests
were unconstrained. The commit adds a method = GET constraint to those
mappings to prevent them from handling other HTTP request methods

rest-notes-spring-hateoas/src/main/java/com/example/notes/IndexController.java

@@ -20,13 +20,14 @@ import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 
 import org.springframework.hateoas.ResourceSupport;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 @RequestMapping("/")
 public class IndexController {
 
-	@RequestMapping
+	@RequestMapping(method=RequestMethod.GET)
 	public ResourceSupport index() {
 		ResourceSupport index = new ResourceSupport();
 		index.add(linkTo(NotesController.class).withRel("notes"));

rest-notes-spring-hateoas/src/main/java/com/example/notes/NotesController.java

@@ -55,7 +55,7 @@ public class NotesController {
 		this.noteResourceAssembler = noteResourceAssembler;
 	}
 
-	@RequestMapping
+	@RequestMapping(method = RequestMethod.GET)
 	Iterable<NoteResource> all() {
 		return this.noteResourceAssembler.toResources(this.noteRepository.findAll());
 	}

rest-notes-spring-hateoas/src/main/java/com/example/notes/TagsController.java

@@ -46,7 +46,7 @@ public class TagsController {
 		this.resourceAssembler = resourceAssembler;
 	}
 
-	@RequestMapping
+	@RequestMapping(method = RequestMethod.GET)
 	Iterable<TagResource> all() {
 		return this.resourceAssembler.toResources(this.repository.findAll());
 	}
@@ -65,7 +65,7 @@ public class TagsController {
 		return httpHeaders;
 	}
 
-	@RequestMapping("/{id}")
+	@RequestMapping(value = "/{id}", method = RequestMethod.GET)
 	Resource<Tag> tag(@PathVariable("id") long id) {
 		Tag tag = this.repository.findOne(id);
 		return this.resourceAssembler.toResource(tag);