Form controller file

HelloController.java

package hello;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;

@Controller
public class HelloController {
	@GetMapping("/hello")
	public String helloForm(Model model) {
		model.addAttribute("hello", new Hello());
		return "hello";
	}

	@PostMapping("/hello")
	public String helloSubmit(@ModelAttribute Hello hello) {
		return "result";
	}
}