001    /*
002     * Copyright 2005 Niclas Hedhman
003     * Copyright 2005-2006 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;
020    
021    import java.io.IOException;
022    import java.net.URI;
023    
024    /** 
025     * The LinkManager is responsible for storing the mapping between a Link
026     * instance and a URI.
027     * @author <a href="http://www.dpml.net">Digital Product Management Laboratory</a>
028     * @version 2.0.2
029     */
030    public interface LinkManager
031    {
032       /** 
033        * Sets the URI for the provided link URI.
034        * The LinkManager is required to persist this information between
035        * JVM restarts and should be persisted on a scope larger than a
036        * single JVM, typically a host or a local area network. LinkManagers
037        * are encouraged to establish other virtual scopes independent of
038        * network topologies.
039        *
040        * @param link the uri of the link
041        * @param target the uri of the target that the link redirects to
042        * @exception IOException if an IO error occurs
043        */
044        void setTargetURI( URI link, URI target ) throws IOException;
045    
046       /** 
047        * Returns the URI that the supplied link URI is referencing.
048        * 
049        * @param link the link uri
050        * @return the target uri
051        * @exception IOException if an IO error occurs
052        */
053        URI getTargetURI( URI link ) throws IOException;
054    
055    }