CreateUser.java

@RequestMapping(method = RequestMethod.POST,
        consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE})
@ResponseStatus(HttpStatus.CREATED)
void create(@RequestBody @Valid User user, HttpServletRequest request, HttpServletResponse response) {
    long userId = userService.create(user);
    String location = ServletUriComponentsBuilder.fromRequestUri(request).path("/{userid}")
            .build()
            .expand(userId).toUriString();
    response.addHeader("Location", location);
}

DeleteUser.java

@RequestMapping(value = "/{userId}",
        method = RequestMethod.DELETE)
@ResponseStatus(HttpStatus.NO_CONTENT)
void delete(@PathVariable("userId") long userId) {
    userService.delete(userId);
}

ReadUser.java

@RequestMapping(value = "/{userId}",
        method = RequestMethod.GET,
        produces = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE})
@ResponseBody
User read(@PathVariable("userId") long userId) {
    return userService.read(userId);
}

UpdateUser.java

@RequestMapping(value = "/{userId}",
        method = RequestMethod.PUT,
        consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE})
@ResponseStatus(HttpStatus.NO_CONTENT)
void update(@PathVariable("userId") long userId, @RequestBody @Valid User user) {
    userService.update(userId, user);
}

User.java

@XmlRootElement
public class User {

    @NotBlank
    @Length(min = 3, max = 30)
    private String name;

    @Email
    private String email;

    public User() {
    }

    public User(String name, String email) {
        this.name = name;
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

UserController.java

@Controller
@RequestMapping("/user")
class UserController {

    private final UserService userService;

    @Autowired
    UserController(UserService userService) {
        this.userService = userService;
    }

    // TODO implement CRUD methods
}

UserService.java

public interface UserService {

    long create(User user);

    User read(long userId) throws UnknownUserException;

    void update(long userId, User user) throws UnknownUserException;

    void delete(long userId) throws UnknownUserException;
}