/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
*/
package org.geotools.gce.imagemosaic.properties;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.geotools.coverage.grid.io.GridFormatFactorySpi;
import org.geotools.factory.FactoryCreator;
import org.geotools.factory.FactoryRegistry;
/**
*
* @author Simone Giannecchini, GeoSolutions SAS
*
*
*
* @source $URL$
*/
public final class PropertiesCollectorFinder {
/**
* The service registry for this manager. Will be initialized only when
* first needed.
*/
private static FactoryRegistry registry;
/**
* Do not allows any instantiation of this class.
*/
private PropertiesCollectorFinder() {
// singleton
}
/**
* Finds all avalaible implementations of {@link GridFormatFactorySpi} which
* have registered using the services mechanism, and that have the
* appropriate libraries on the classpath.
*
* @return An unmodifiable {@link Set} of all discovered datastores which
* have registered factories, and whose available method returns
* true.
*/
public static synchronized Set<PropertiesCollectorSPI> getPropertiesCollectorSPI() {
// get all GridFormatFactorySpi implementations
scanForPlugins();
final Iterator<PropertiesCollectorSPI> it = getServiceRegistry().getServiceProviders(PropertiesCollectorSPI.class, true);
final Set<PropertiesCollectorSPI> collectors= new HashSet<PropertiesCollectorSPI>();
while (it.hasNext()) {
final PropertiesCollectorSPI spi = (PropertiesCollectorSPI) it.next();
if (spi.isAvailable())
collectors.add(spi);
}
return Collections.unmodifiableSet(collectors);
}
/**
* Returns the service registry. The registry will be created the first time
* this method is invoked.
*/
private static FactoryRegistry getServiceRegistry() {
assert Thread.holdsLock(PropertiesCollectorFinder.class);
if (registry == null) {
registry = new FactoryCreator(Arrays.asList(new Class<?>[] { PropertiesCollectorSPI.class }));
}
return registry;
}
/**
* Scans for factory plug-ins on the application class path. This method is
* needed because the application class path can theoretically change, or
* additional plug-ins may become available. Rather than re-scanning the
* classpath on every invocation of the API, the class path is scanned
* automatically only on the first invocation. Clients can call this method
* to prompt a re-scan. Thus this method need only be invoked by
* sophisticated applications which dynamically make new plug-ins available
* at runtime.
*/
public static synchronized void scanForPlugins() {
getServiceRegistry().scanForPlugins();
}
}