Spring Boot API with Multiple Controllers?

Apparently Controllers in different packages can't be seen with @springbootApplication notation in the main class. The solution explained here, https://kamwo.me/java-spring-boot-mvc-ontroller-not-called/.

I'm trying Spring Boot and got same problem, and just fixed it, I post my solution here because I think it maybe helpful for someone.

First, put application class ( which contain main method) at the root of controllers's package:

com.example.demo
              |
              +-> controller
              |      |
              |      +--> IndexController.java
              |      +--> LoginController.java
              |
              +-> Application.java

Application.java

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Spring will scan all the components of sub-packages of demo package

IndexController.java (return index.html view)

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping(value = {""})
public class IndexController {

    @GetMapping(value = {""})
    public ModelAndView index() {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        return modelAndView;
    }

}

LoginController.java (return login.html view)

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping(value = {"/login"})
public class LoginController {
    @GetMapping(value = {""})
    public ModelAndView login() {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("login");
        return modelAndView;
    }
}

And now I can enter Index view : http://localhost:8080/demo/ and Login view : http://localhost:8080/demo/login