How to port SpringMVC Application to SpringREST?

Question

We have created SpringMVC application using Spring-Boot and Thymleaf. Now as per new requirement, I have to convert them to SPring-REST for external application consumption(AngularJS and Android App) without affecting the thymleaf pages.

Please assist.

Below is the sample code. Like this many controllers are there

@Controller
@RequestMapping(value = "/admin/register")
@SessionAttributes("roles")
public class AdminRegisterController {
    @Autowired
    private UserService userService;

    @Autowired
    private RoleRepository roleRepository;

    @ModelAttribute("user")
    public User constructUser() {
        return new User();
    }

    @ModelAttribute("roles")
    public List<Role> InitializeRoles() {
        return roleRepository.findAll();
    }

    // Display Register Page
    @RequestMapping
    public String showRegister(Model model) {
        model.addAttribute("current", "register");
        return "register";
    }

    // Inserting new User
    @RequestMapping(method = RequestMethod.POST)
    public ModelAndView doRegister(@Valid @ModelAttribute("user") User user, BindingResult result) {
        if (result.hasErrors()) {
            return new ModelAndView("register");
        }
        userService.save(user);
        RedirectView redirectView = new RedirectView("/admin/register?success=true");
        redirectView.setExposeModelAttributes(false);
        return new ModelAndView(redirectView);
    }


    @RequestMapping("/available")
    @ResponseBody
    public String available(@RequestParam String username) {
        User user = userService.findOne(username);
        Boolean available = userService.findOne(username) == null;
        return available.toString();
    }


}

Answer 1

You can use the javax.ws.rs api for doing that.

<dependency>
    <groupId>javax.ws.rs</groupId>
    <artifactId>javax.ws.rs-api</artifactId>
    <version>2.0</version>
</dependency>

And use @RestController instead of simple @Controllers in your current code.