Adds service implementation documentation

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/Authenticator.java

@@ -82,6 +82,25 @@ public interface Authenticator<C extends AuthenticatorConfiguration> {
 	 * @author <a href="http://www.rogiel.com">Rogiel</a>
 	 */
 	public interface AuthenticatorConfiguration {
+		/**
+		 * Checks whether the configuration object can be casted to
+		 * <code>type</code>
+		 * 
+		 * @param type
+		 *            the casting type
+		 * @return <code>true</code> if this object can be casted to
+		 *         <code>type</code>
+		 */
+		boolean is(Class<? extends AuthenticatorConfiguration> type);
 
+		/**
+		 * Casts this object to <code>type</code>. If cannot be casted,
+		 * <code>null</code> is returned.
+		 * 
+		 * @param type
+		 *            the casting type
+		 * @return the casted configuration
+		 */
+		<T extends AuthenticatorConfiguration> T as(Class<T> type);
 	}
 }

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/Downloader.java

@@ -208,6 +208,25 @@ public interface Downloader<C extends DownloaderConfiguration> {
 	 * @author <a href="http://www.rogiel.com">Rogiel</a>
 	 */
 	public interface DownloaderConfiguration {
+		/**
+		 * Checks whether the configuration object can be casted to
+		 * <code>type</code>
+		 * 
+		 * @param type
+		 *            the casting type
+		 * @return <code>true</code> if this object can be casted to
+		 *         <code>type</code>
+		 */
+		boolean is(Class<? extends DownloaderConfiguration> type);
 
+		/**
+		 * Casts this object to <code>type</code>. If cannot be casted,
+		 * <code>null</code> is returned.
+		 * 
+		 * @param type
+		 *            the casting type
+		 * @return the casted configuration
+		 */
+		<T extends DownloaderConfiguration> T as(Class<T> type);
 	}
 }

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/Uploader.java

@@ -80,6 +80,26 @@ public interface Uploader<C extends UploaderConfiguration> {
 	 * @author <a href="http://www.rogiel.com">Rogiel</a>
 	 */
 	public interface UploaderConfiguration {
+		/**
+		 * Checks whether the configuration object can be casted to
+		 * <code>type</code>
+		 * 
+		 * @param type
+		 *            the casting type
+		 * @return <code>true</code> if this object can be casted to
+		 *         <code>type</code>
+		 */
+		boolean is(Class<? extends UploaderConfiguration> type);
+
+		/**
+		 * Casts this object to <code>type</code>. If cannot be casted,
+		 * <code>null</code> is returned.
+		 * 
+		 * @param type
+		 *            the casting type
+		 * @return the casted configuration
+		 */
+		<T extends UploaderConfiguration> T as(Class<T> type);
 	}
 
 	/**

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/config/NullAuthenticatorConfiguration.java

@@ -35,4 +35,14 @@ public final class NullAuthenticatorConfiguration implements
 
 	private NullAuthenticatorConfiguration() {
 	}
+
+	@Override
+	public boolean is(Class<? extends AuthenticatorConfiguration> type) {
+		return false;
+	}
+
+	@Override
+	public <T extends AuthenticatorConfiguration> T as(Class<T> type) {
+		return null;
+	}
 }

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/config/NullDownloaderConfiguration.java

@@ -34,4 +34,14 @@ public final class NullDownloaderConfiguration implements
 
 	private NullDownloaderConfiguration() {
 	}
+
+	@Override
+	public boolean is(Class<? extends DownloaderConfiguration> type) {
+		return false;
+	}
+
+	@Override
+	public <T extends DownloaderConfiguration> T as(Class<T> type) {
+		return null;
+	}
 }

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/config/NullUploaderConfiguration.java

@@ -33,4 +33,14 @@ public final class NullUploaderConfiguration implements UploaderConfiguration {
 
 	private NullUploaderConfiguration() {
 	}
+
+	@Override
+	public boolean is(Class<? extends UploaderConfiguration> type) {
+		return false;
+	}
+
+	@Override
+	public <T extends UploaderConfiguration> T as(Class<T> type) {
+		return null;
+	}
 }

httpchannel-api/src/main/java/com/rogiel/httpchannel/service/helper/Services.java

@@ -25,6 +25,7 @@ import java.util.ServiceLoader;
 import com.rogiel.httpchannel.service.DownloadService;
 import com.rogiel.httpchannel.service.Service;
 import com.rogiel.httpchannel.service.ServiceID;
+import com.rogiel.httpchannel.service.UploadService;
 
 /**
  * @author <a href="http://www.rogiel.com">Rogiel</a>
@@ -73,6 +74,36 @@ public class Services {
 		}
 		return null;
 	}
+	
+	/**
+	 * Tries to detect which service has the given <tt>id</tt>
+	 * 
+	 * @param id
+	 *            the service id
+	 * @return the matched service
+	 */
+	public static UploadService<?> getUploadService(ServiceID id) {
+		for (final Service service : iterate()) {
+			if (service.getServiceID().equals(id))
+				return (UploadService<?>) service;
+		}
+		return null;
+	}
+	
+	/**
+	 * Tries to detect which service has the given <tt>id</tt>
+	 * 
+	 * @param id
+	 *            the service id
+	 * @return the matched service
+	 */
+	public static DownloadService<?> getDownloadService(ServiceID id) {
+		for (final Service service : iterate()) {
+			if (service.getServiceID().equals(id))
+				return (DownloadService<?>) service;
+		}
+		return null;
+	}
 
 	/**
 	 * Creates a new {@link Iterable} instance to iterate over services