001    /*
002     * Cumulus4j - Securing your data in the cloud - http://cumulus4j.org
003     * Copyright (C) 2011 NightLabs Consulting GmbH
004     *
005     * This program is free software: you can redistribute it and/or modify
006     * it under the terms of the GNU Affero General Public License as
007     * published by the Free Software Foundation, either version 3 of the
008     * License, or (at your option) any later version.
009     *
010     * This program is distributed in the hope that it will be useful,
011     * but WITHOUT ANY WARRANTY; without even the implied warranty of
012     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
013     * GNU Affero General Public License for more details.
014     *
015     * You should have received a copy of the GNU Affero General Public License
016     * along with this program.  If not, see <http://www.gnu.org/licenses/>.
017     */
018    package org.cumulus4j.keymanager.back.shared;
019    
020    import javax.xml.bind.annotation.XmlRootElement;
021    
022    /**
023     * {@link Response} implementation not containing any data and symbolising Java's <code>null</code> value.
024     *
025     * @author Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de
026     */
027    @XmlRootElement
028    public class NullResponse
029    extends Response
030    {
031            private static final long serialVersionUID = 1L;
032    
033            /**
034             * Create a <code>NullResponse</code> without a prior request. This is just used as filler
035             * without being forwarded to any requester. It circumvents the problem that Jersey has a problem
036             * when a REST service (aka resource) method expecting an entity should be called without one.
037             */
038            public NullResponse() { }
039    
040            /**
041             * Create a <code>NullResponse</code> as answer to a prior request. It is
042             * processed like any other response, i.e. forwarded to the requester, but finally
043             * translated to <code>null</code>
044             * (<code>org.cumulus4j.store.crypto.keymanager.messagebroker.MessageBroker.query(Class<R>, Request)</code>
045             * never returns a <code>NullResponse</code> instance; instead it returns <code>null</code>).
046             * @param request the request that is answered by this new <code>NullResponse</code> instance.
047             */
048            public NullResponse(Request request)
049            {
050                    super(request);
051            }
052    }