ObjectClassDefinition 개체로서의 OSGi 구성

package com.adobe.aem.wknd.examples.core.adventures.impl;

import java.util.Random;

import com.adobe.aem.wknd.examples.core.adventures.Activities;

import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Deactivate;
import org.osgi.service.metatype.annotations.AttributeDefinition;
import org.osgi.service.metatype.annotations.Designate;
import org.osgi.service.metatype.annotations.ObjectClassDefinition;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Component(
    service = { Activities.class }
)
@Designate(ocd = ActivitiesImpl.Config.class)
public class ActivitiesImpl implements Activities {
    private static final Logger log = LoggerFactory.getLogger(ActivitiesImpl.class);

    @ObjectClassDefinition(
        name = "WKND Examples - Activities Service",
        description = "OSGi Service providing information about WKND Adventures activities"
    )
    @interface Config {

        @AttributeDefinition(
            name = "WKND Activities",
            description = "Human-friendly list of activity names"
        )
        String[] activities() default { "Hiking", "Jogging", "Walking" };

        @AttributeDefinition(
            name = "Random Activity Seed",
            description = "Seed used to randomize activity selection"
        )
        int random_seed() default 10;

    }

    private String[] activities;

    private Random random;

    /**
     * @return the name of a random WKND adventure activity
     */
    public String getRandomActivity() {
        int randomIndex = random.nextInt(activities.length);
        return activities[randomIndex];
    }

    @Activate
    protected void activate(Config config) {

        this.activities = config.activities();

        final int randomSeed = config.random_seed();

        this.random = new Random(randomSeed);

        log.info("Activated ActivitiesImpl with activities [ {} ]", String.join(", ", this.activities));
    }

    @Deactivate
    protected void deactivate() {
        log.info("ActivitiesImpl has been deactivated!");
    }
}