001    /*
002     * Copyright 2005 Niclas Hedhman
003     * Copyright 2005 Stephen McConnell
004     * Licensed  under the  Apache License,  Version 2.0  (the "License");
005     * you may not use  this file  except in  compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *   http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed  under the  License is distributed on an "AS IS" BASIS,
012     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
013     * implied.
014     *
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package net.dpml.transit.link;
020    
021    import java.io.IOException;
022    
023    import java.net.URI;
024    
025    /** 
026     * The LinkManager is responsible for storing the mapping between a Link
027     * instance and a URI.
028     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
029     * @version 1.0.1
030     */
031    public interface LinkManager
032    {
033       /** 
034        * Sets the URI for the provided link URI.
035        * The LinkManager is required to persist this information between
036        * JVM restarts and should be persisted on a scope larger than a
037        * single JVM, typically a host or a local area network. LinkManagers
038        * are encouraged to establish other virtual scopes independent of
039        * network topologies.
040        *
041        * @param link the uri of the link
042        * @param target the uri of the target that the link redirects to
043        * @exception IOException if an IO error occurs
044        */
045        void setTargetURI( URI link, URI target ) throws IOException;
046    
047       /** 
048        * Returns the URI that the supplied link URI is referencing.
049        * 
050        * @param link the link uri
051        * @return the target uri
052        * @exception IOException if an IO error occurs
053        */
054        URI getTargetURI( URI link ) throws IOException;
055    
056    }