예제 3-19 애너테이션을 사용해 빈 정의를 생성하는 클래스 예([[setter-injection]] HelloWorldMessageProvider.java, StandardOutMessageRenderer)

package com.apress.prospring5.ch2.decoupled;

import com.apress.prospring5.ch2.decoupled.MessageProvider;
import org.springframework.stereotype.Component;

//간단한 빈
@Component("provider")
public class HelloWorldMessageProvider implements MessageProvider {

    @Override
    public String getMessage() {
        return "Hello World!";
    }
}

import com.apress.prospring5.ch2.decoupled.MessageProvider;
import com.apress.prospring5.ch2.decoupled.MessageRenderer;
import org.springframework.stereotype.Service;
import org.springframework.beans.factory.annotation.Autowired;

//복잡한 서비스 빈
@Service("renderer")
public class StandardOutMessageRenderer
    implements MessageRenderer {

    private MessageProvider messageProvider;

    @Override
    public void render() {
        if (messageProvider == null) {
            throw new RuntimeException(
                "messageProvider 클래스의 프로퍼티를 설정해야 합니다:"
                + StandardOutMessageRenderer.class.getName());
        }

        System.out.println(messageProvider.getMessage());
    }

    @Override
    @Autowired
    public void setMessageProvider(MessageProvider provider) {
        this.messageProvider = provider;
    }

    @Override
    public MessageProvider getMessageProvider() {
        return this.messageProvider;
    }
}