/**
* Copyright 2005-2014 Restlet
*
* The contents of this file are subject to the terms of one of the following
* open source licenses: Apache 2.0 or or EPL 1.0 (the "Licenses"). You can
* select the license that you prefer but you may not use this file except in
* compliance with one of these Licenses.
*
* You can obtain a copy of the Apache 2.0 license at
* http://www.opensource.org/licenses/apache-2.0
*
* You can obtain a copy of the EPL 1.0 license at
* http://www.opensource.org/licenses/eclipse-1.0
*
* See the Licenses for the specific language governing permissions and
* limitations under the Licenses.
*
* Alternatively, you can obtain a royalty free commercial license with less
* limitations, transferable or non-transferable, directly at
* http://restlet.com/products/restlet-framework
*
* Restlet is a registered trademark of Restlet S.A.S.
*/
package org.restlet.service;
import java.util.List;
import org.restlet.Request;
import org.restlet.engine.application.Conneg;
import org.restlet.engine.application.FlexibleConneg;
import org.restlet.engine.application.StrictConneg;
import org.restlet.representation.Variant;
/**
* Application service negotiating the preferred resource variants. This service
* is leveraged by server-side and client-side content negotiation, annotated
* method dispatching, and so on.
*
* @author Jerome Louvel
*/
public class ConnegService extends Service {
/**
* Indicates if the conneg algorithm should strictly respect client
* preferences or be more flexible.
*/
private volatile boolean strict;
/**
* Constructor.
*/
public ConnegService() {
this(true);
}
/**
* Constructor.
*
* @param enabled
* True if the service has been enabled.
*/
public ConnegService(boolean enabled) {
super(enabled);
this.strict = false;
}
/**
* Returns the best variant representation for a given resource according
* the the client preferences.<br>
* A default language is provided in case the variants don't match the
* client preferences.
*
* @param variants
* The list of variants to compare.
* @param request
* The request including client preferences.
* @param metadataService
* The metadata service used to get default metadata values.
* @return The preferred variant.
* @see <a
* href="http://httpd.apache.org/docs/2.2/en/content-negotiation.html#algorithm">Apache
* content negotiation algorithm</a>
*/
public Variant getPreferredVariant(List<? extends Variant> variants,
Request request, MetadataService metadataService) {
Conneg conneg = isStrict() ? new StrictConneg(request, metadataService)
: new FlexibleConneg(request, metadataService);
return conneg.getPreferredVariant(variants);
}
/**
* Indicates if the conneg algorithm should strictly respect client
* preferences or be more flexible. Value is false by default.
*
* @return True if the conneg algorithm should strictly respect client
* preferences.
*/
public boolean isStrict() {
return strict;
}
/**
* Indicates if the conneg algorithm should strictly respect client
* preferences or be more flexible.
*
* @param strict
* True if the conneg algorithm should strictly respect client
* preferences.
*/
public void setStrict(boolean strict) {
this.strict = strict;
}
}