package com.example.springfigure;

public abstract class Figure {
    public abstract String printType();
}

package com.example.springfigure;

public class Circle extends Figure {
    @Override
    public String printType() {
        return "I am a circle!";
    }
}

package com.example.springfigure;

public class Rectangle extends Figure {
    @Override
    public String printType() {
       return "I am a rectangle!";
    }
}

package com.example.springfigure;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AppConfig {
    @Bean
    public Figure circle() {
        return new Circle();
    }

    @Bean
    public Figure rectangle() {
        return new Rectangle();
    }
}

package com.example.springfigure;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class MainController {
    @Qualifier("rectangle")
    private Figure figure;

    public MainController(Figure figure) {
        this.figure = figure;
    }

    @GetMapping("/")
    public String showFigure(Model model) {
        model.addAttribute("msg", figure.printType());
        return "figure";
    }
}

@Controller
public class MainController {
    @Autowired
    @Qualifier("rectangle")
    private Figure figure;

    @GetMapping("/")
    public String showFigure(Model model) {
        model.addAttribute("msg", figure.printType());
        return "figure";
    }
}

public MainController(@Qualifier(@Value("${type}")) Figure figure) {
        this.figure = figure;
}