Gatekeeper component example

gistfile1.java

package org.example.exchange.gatekeeper;

import java.io.File;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import org.example.osgi.utils.components.ComponentHelper;
import org.osgi.service.component.ComponentContext;

import aQute.bnd.annotation.component.Activate;
import aQute.bnd.annotation.component.Component;
import aQute.bnd.annotation.component.Deactivate;

@Component(name = GatekeeperComp.COMP_NAME)
public class GatekeeperComp {
  
	static final String COMP_NAME = "org.example.exchange.gatekeeper";

	private ScheduledExecutorService executor;

	@Activate
	void activate(final ComponentContext context) {
		executor = Executors.newScheduledThreadPool(1);
		Runnable check = new Runnable() {
			public void run() {
				if (new File("licence.txt").exists()) {
					context.enableComponent(null);
				} else {
					List<String> names = ComponentHelper.getComponentNames(context.getBundleContext());
					for (String name : names) {
						if (!COMP_NAME.equals(name)) {
							context.disableComponent(name);
						}
					}
				}
			}
		};
		executor.scheduleAtFixedRate(check, 2, 2, TimeUnit.SECONDS);
	}
	
	@Deactivate
	void deactivate() {
		executor.shutdown();
	}
}