001    /*
002     * Copyright 2005 Stephen McConnell
003     *
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.tools.tasks;
020    
021    import net.dpml.library.Library;
022    import net.dpml.library.Resource;
023    import net.dpml.library.ResourceNotFoundException;
024    
025    import net.dpml.tools.Context;
026    
027    import org.apache.tools.ant.BuildException;
028    
029    /**
030     * The plugin task handles the establishment of ant tasks, listeners, and antlibs derived
031     * from a classloader established by the tools sub-system.
032     *
033     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
034     * @version 1.1.3
035     */
036    public class PluginTask extends net.dpml.transit.tools.PluginTask
037    {
038        private String m_ref;
039        
040       /**
041        * Set the ref address of a plugin resource.
042        * @param ref a resource ref
043        */
044        public void setRef( String ref )
045        {
046            m_ref = ref;
047        }
048        
049       /**
050        * Task initialization.
051        */
052        public void init()
053        {
054            super.init();
055            Thread.currentThread().setContextClassLoader( getClass().getClassLoader() );
056        }
057        
058       /**
059        * Task execution.
060        */
061        public void execute()
062        {
063            if( null != m_ref )
064            {
065                Context context = (Context) getProject().getReference( "project.context" );
066                if( null == context )
067                {
068                    final String error = 
069                      "Missing 'project.context' reference.";
070                    throw new IllegalStateException( error );
071                }
072                Library library = context.getLibrary();
073                try
074                {
075                    Resource resource = library.getResource( m_ref );
076                    String uri = resource.getArtifact( "plugin" ).toURI().toString();
077                    setUri( uri );
078                }
079                catch( ResourceNotFoundException e )
080                {
081                    String message = e.getMessage();
082                    throw new BuildException( message, e, getLocation() );
083                }
084                catch( Exception e )
085                {
086                    final String error = 
087                      "Unexpected error while attempting to initiaze plugin task uri.";
088                    throw new BuildException( error, e );
089                }
090            }
091            
092            super.execute();
093        }
094    }