/*
* #%L
* JBossOSGi Resolver API
* %%
* Copyright (C) 2010 - 2013 JBoss by Red Hat
* %%
* This program 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, either version 2.1 of the
* License, or (at your option) any later version.
*
* This program 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 General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* <http://www.gnu.org/licenses/lgpl-2.1.html>.
* #L%
*/
package org.jboss.gravia.resolver;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import org.jboss.gravia.resource.Capability;
import org.jboss.gravia.resource.IdentityNamespace;
import org.jboss.gravia.resource.Resource;
import org.jboss.gravia.resource.Version;
import org.jboss.gravia.resource.Wiring;
import org.jboss.gravia.resource.spi.AbstractCapability;
/**
* The default {@link PreferencePolicy}.
*
* @author thomas.diesler@jboss.com
* @since 02-Apr-2012
*/
public class DefaultPreferencePolicy implements PreferencePolicy {
private final Comparator<Capability> comparator;
public DefaultPreferencePolicy(final Map<Resource, Wiring> wirings) {
comparator = new Comparator<Capability>() {
@Override
public int compare(Capability cap1, Capability cap2) {
// Prefer already wired
if (wirings != null) {
Wiring w1 = wirings.get(cap1.getResource());
Wiring w2 = wirings.get(cap2.getResource());
if (w1 != null && w2 == null)
return -1;
if (w1 == null && w2 != null)
return +1;
}
// Prefer higher version
Version v1 = AbstractCapability.getVersion(cap1, IdentityNamespace.CAPABILITY_VERSION_ATTRIBUTE);
Version v2 = AbstractCapability.getVersion(cap2, IdentityNamespace.CAPABILITY_VERSION_ATTRIBUTE);
return v2.compareTo(v1);
}
}; }
@Override
public void sort(List<Capability> providers) {
Collections.sort(providers, comparator);
}
@Override
public Comparator<Capability> getComparator() {
return comparator;
}
}