ConsolePrinter.java

package org.example;

import org.springframework.stereotype.Component;

@Component

public class ConsolePrinter implements Printer {
    @Override
    public void printMessage(String message) {
        System.out.println("Console : " + message);
    }
}

FilePrinter.java

package org.example;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component

public class FilePrinter {
    private final Printer printer;

    @Autowired
    public FilePrinter(Printer printer) {
        this.printer = printer;
    }

    public void play() {
        printer.printMessage("Hello World");
        System.out.println("파일이 출력됩니다.");
    }
}

Main.java

package org.example;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Main {
    public static void main(String[] args) {
        // IoC 컨테이너 초기화
        ApplicationContext context = new AnnotationConfigApplicationContext("org.example");

        // Spring container가 관리하는 객체 가져오기
        FilePrinter fileprinter = context.getBean(FilePrinter.class);
        fileprinter.play();

    }
}

Printer.java

package org.example;

public interface Printer {
    void printMessage(String message);
}