Basic class scan for external logic's with Interface --> Implementation with @foo.bla.Component. Think a better way for this scan.

ExternalComponentScanning.java

package br.inf.carlos.dindin.components.scan;

import java.io.IOException;
import java.net.URL;
import java.util.Map;
import java.util.Set;

import org.apache.log4j.Logger;
import org.scannotation.AnnotationDB;
import org.scannotation.WarUrlFinder;

import br.com.caelum.vraptor.ComponentRegistry;
import br.com.caelum.vraptor.ioc.guice.GuiceProvider;
import br.inf.carlos.base.cdi.provider.Component;

public class ExternalComponentScanning extends GuiceProvider{

	private static final Logger logger = Logger.getLogger(ExternalComponentScanning.class);
	
	private void register(ComponentRegistry registry, Set<String> keySet) throws ClassNotFoundException{
		
		if(keySet == null){
			return;
		}
		
		for (String clazz : keySet) {
			Class<?> componentClass = Class.forName(clazz);
			
			Class<?>[] interfaces = componentClass.getInterfaces();
			
			if(interfaces == null || interfaces.length == 0){
				logger.warn("No interfaces found for class " + componentClass.getName() + ". Only class will be provided by Container.");
				registry.register(componentClass, componentClass);
			}
			else{
				logger.info("Providing " + interfaces[0].getName() + " for class " + componentClass.getName() + ".");
				registry.register(interfaces[0], componentClass);
			}
		}
	}
	
	@Override
	protected void registerCustomComponents(ComponentRegistry registry) {
		
		try {
			URL[] urls = WarUrlFinder.findWebInfLibClasspaths(this.context);
			
			AnnotationDB db = new AnnotationDB();
			db.setScanClassAnnotations(true);
			db.scanArchives(urls);
			Map<String, Set<String>> index = db.getAnnotationIndex();
			this.register(registry, index.get(Component.class.getName()));
			
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}
}