package org.codehaus.plexus.component.discovery;
import org.codehaus.classworlds.ClassRealm;
import org.codehaus.plexus.component.repository.ComponentSetDescriptor;
import org.codehaus.plexus.configuration.PlexusConfigurationException;
import org.codehaus.plexus.context.Context;
import org.codehaus.plexus.context.ContextMapAdapter;
import org.codehaus.plexus.util.IOUtil;
import org.codehaus.plexus.util.InterpolationFilterReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
/**
* @author <a href="mailto:jason@maven.org">Jason van Zyl</a>
* @author <a href="mailto:trygvis@inamo.no">Trygve Laugstøl</a>
* @version $Id: AbstractComponentDiscoverer.java 2665 2005-10-12 05:37:44Z brett $
*/
public abstract class AbstractComponentDiscoverer
implements ComponentDiscoverer
{
private ComponentDiscovererManager manager;
// ----------------------------------------------------------------------
// Abstract methods
// ----------------------------------------------------------------------
protected abstract String getComponentDescriptorLocation();
protected abstract ComponentSetDescriptor createComponentDescriptors( Reader reader, String source )
throws PlexusConfigurationException;
// ----------------------------------------------------------------------
// ComponentDiscoverer
// ----------------------------------------------------------------------
public void setManager( ComponentDiscovererManager manager )
{
this.manager = manager;
}
public List findComponents( Context context, ClassRealm classRealm )
throws PlexusConfigurationException
{
List componentSetDescriptors = new ArrayList();
Enumeration resources;
try
{
resources = classRealm.findResources( getComponentDescriptorLocation() );
}
catch ( IOException e )
{
throw new PlexusConfigurationException( "Unable to retrieve resources for: " +
getComponentDescriptorLocation() + " in class realm: " + classRealm.getId() );
}
for ( Enumeration e = resources; e.hasMoreElements(); )
{
URL url = (URL) e.nextElement();
InputStreamReader reader = null;
try
{
URLConnection conn = url.openConnection();
conn.setUseCaches( false );
conn.connect();
reader = new InputStreamReader( conn.getInputStream() );
InterpolationFilterReader input = new InterpolationFilterReader( reader,
new ContextMapAdapter( context ) );
ComponentSetDescriptor componentSetDescriptor = createComponentDescriptors( input, url.toString() );
componentSetDescriptors.add( componentSetDescriptor );
// Fire the event
ComponentDiscoveryEvent event = new ComponentDiscoveryEvent( componentSetDescriptor );
manager.fireComponentDiscoveryEvent( event );
}
catch ( IOException ex )
{
throw new PlexusConfigurationException( "Error reading configuration " + url, ex );
}
finally
{
IOUtil.close( reader );
}
}
return componentSetDescriptors;
}
}