Spring. Defining Spring Beans with Java Code (no XML)

 package com.example.demo;

public interface FortuneService {

    public String getFortune();

}

package com.example.demo;

public class SadFortuneService implements FortuneService{
    @Override
    public String getFortune() {
        return "Today is a sad day";
    }
}
package com.example.demo;

public interface Coach {

    public String getDailyWorkout();

    public String getDailyFortune();

}
package com.example.demo;

public class SwimCoach implements Coach {

    private FortuneService fortuneService;

    public SwimCoach(FortuneService fortuneService) {
        this.fortuneService = fortuneService;
    }

    @Override
    public String getDailyWorkout() {
        return "Swim 1000 meters as a warm up.";
    }

    @Override
    public String getDailyFortune() {
        return fortuneService.getFortune();
    }
}
package com.example.demo;

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

@Configuration
//@ComponentScan("com.example.demo")
public class SportConfig {

    @Bean
    public FortuneService sadFortuneService() {
        return new SadFortuneService();
    }

    @Bean
    public Coach swimCoach() {
        return new SwimCoach(sadFortuneService());
    }
}
package com.example.demo;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class SwimJavaConfigDemoApp {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SportConfig.class);
        Coach coach = context.getBean("swimCoach", Coach.class);
        System.out.println(coach.getDailyWorkout());
        System.out.println(coach.getDailyFortune());
        context.close();
    }
}