| /****************************************************************************** |
| * Copyright (c) 2008 Oracle |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Konstantin Komissarchik - initial implementation and ongoing maintenance |
| ******************************************************************************/ |
| |
| package org.eclipse.jst.common.project.facet.core.libprov.internal; |
| |
| import static org.eclipse.jst.common.project.facet.core.internal.FacetedProjectFrameworkJavaPlugin.PLUGIN_ID; |
| import static org.eclipse.jst.common.project.facet.core.internal.FacetedProjectFrameworkJavaPlugin.log; |
| import static org.eclipse.wst.common.project.facet.core.util.internal.PluginUtil.findExtensions; |
| import static org.eclipse.wst.common.project.facet.core.util.internal.PluginUtil.findRequiredAttribute; |
| import static org.eclipse.wst.common.project.facet.core.util.internal.PluginUtil.getTopLevelElements; |
| import static org.eclipse.wst.common.project.facet.core.util.internal.PluginUtil.instantiate; |
| import static org.eclipse.wst.common.project.facet.core.util.internal.PluginUtil.loadClass; |
| |
| import java.lang.ref.WeakReference; |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.eclipse.core.resources.IProject; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.jst.common.project.facet.core.libprov.ILibraryProvider; |
| import org.eclipse.jst.common.project.facet.core.libprov.LegacyLibraryProviderDetector; |
| import org.eclipse.wst.common.project.facet.core.IProjectFacet; |
| import org.eclipse.wst.common.project.facet.core.util.internal.PluginUtil.InvalidExtensionException; |
| |
| /** |
| * Contains the logic for processing the <code>legacyLibraryProviderDetectors</code> extension point. |
| * |
| * @author <a href="mailto:konstantin.komissarchik@oracle.com">Konstantin Komissarchik</a> |
| */ |
| |
| public final class LegacyLibraryProviderDetectorsExtensionPoint |
| { |
| public static final String EXTENSION_POINT_ID = "legacyLibraryProviderDetectors"; //$NON-NLS-1$ |
| |
| private static final String ATTR_CLASS = "class"; //$NON-NLS-1$ |
| private static final String EL_DETECTOR = "detector"; //$NON-NLS-1$ |
| |
| private static List<DetectorExtension> extensions = null; |
| |
| public static synchronized ILibraryProvider detect( final IProject project, |
| final IProjectFacet facet ) |
| { |
| readExtensions(); |
| |
| for( Iterator<DetectorExtension> itr = extensions.iterator(); itr.hasNext(); ) |
| { |
| final DetectorExtension extension = itr.next(); |
| final LegacyLibraryProviderDetector detector; |
| |
| try |
| { |
| detector = extension.createDetector(); |
| } |
| catch( InvalidExtensionException e ) |
| { |
| // Problem already reported to the user in the log. Removing the extension from |
| // the list so that we don't keep tripping over it in the future. |
| |
| itr.remove(); |
| continue; |
| } |
| |
| try |
| { |
| final ILibraryProvider provider = detector.detect( project, facet ); |
| |
| if( provider != null ) |
| { |
| return provider; |
| } |
| } |
| catch( Exception e ) |
| { |
| log( e ); |
| } |
| } |
| |
| return null; |
| } |
| |
| private static synchronized void readExtensions() |
| { |
| if( extensions != null ) |
| { |
| return; |
| } |
| |
| extensions = new ArrayList<DetectorExtension>(); |
| |
| for( IConfigurationElement element |
| : getTopLevelElements( findExtensions( PLUGIN_ID, EXTENSION_POINT_ID ) ) ) |
| { |
| if( element.getName().equals( EL_DETECTOR ) ) |
| { |
| try |
| { |
| final String pluginId = element.getContributor().getName(); |
| final String className = findRequiredAttribute( element, ATTR_CLASS ); |
| extensions.add( new DetectorExtension( pluginId, className ) ); |
| } |
| catch( InvalidExtensionException e ) |
| { |
| // Continue. The problem has been reported to the user via the log. |
| } |
| } |
| } |
| } |
| |
| private static final class DetectorExtension |
| { |
| private final String pluginId; |
| private final String className; |
| private WeakReference<Class<? extends LegacyLibraryProviderDetector>> classWeakReference; |
| |
| public DetectorExtension( final String pluginId, |
| final String className ) |
| { |
| this.pluginId = pluginId; |
| this.className = className; |
| } |
| |
| public synchronized LegacyLibraryProviderDetector createDetector() |
| |
| throws InvalidExtensionException |
| |
| { |
| Class<? extends LegacyLibraryProviderDetector> detectorClass |
| = this.classWeakReference == null ? null : this.classWeakReference.get(); |
| |
| if( detectorClass == null ) |
| { |
| detectorClass = loadClass( this.pluginId, this.className, LegacyLibraryProviderDetector.class ); |
| |
| if( detectorClass == null ) |
| { |
| throw new InvalidExtensionException(); |
| } |
| |
| this.classWeakReference = new WeakReference<Class<? extends LegacyLibraryProviderDetector>>( detectorClass ); |
| } |
| |
| final LegacyLibraryProviderDetector detector = instantiate( this.pluginId, detectorClass ); |
| |
| if( detector == null ) |
| { |
| throw new InvalidExtensionException(); |
| } |
| |
| return detector; |
| } |
| } |
| |
| } |