LoadShedControlConfigPriorityComparator.java

/* ==================================================================
 * LoadShedControlConfigPriorityComparator.java - 27/06/2015 5:06:21 pm
 * 
 * Copyright 2007-2015 SolarNetwork.net Dev Team
 * 
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 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 Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 
 * 02111-1307 USA
 * ==================================================================
 */

package net.solarnetwork.node.control.loadshedder;

import java.util.Comparator;

/**
 * Comparator for {@link LoadShedControlConfig} to order by priority from lowest to
 * highest, with <em>null<em> sorted last.
 * A secondary sort on <b>controlId</b> is used if both priority values are null.
 * 
 * @author matt
 * @version 1.0
 */
public class LoadShedControlConfigPriorityComparator implements Comparator<LoadShedControlConfig> {

	/**
	 * A static instance of the comparator.
	 */
	public static final LoadShedControlConfigPriorityComparator COMPARATOR = new LoadShedControlConfigPriorityComparator();

	@Override
	public int compare(LoadShedControlConfig o1, LoadShedControlConfig o2) {
		if ( o1.getPriority() != null && o2.getPriority() != null ) {
			return o1.getPriority().compareTo(o2.getPriority());
		}
		if ( o2.getPriority() == null && o1.getPriority() != null ) {
			return -1;
		}
		if ( o1.getPriority() == null && o2.getPriority() != null ) {
			return 1;
		}
		if ( o1.getControlId() != null && o2.getControlId() != null ) {
			return o1.getControlId().compareToIgnoreCase(o2.getControlId());
		}
		if ( o2.getControlId() == null ) {
			return -1;
		}
		if ( o1.getControlId() == null ) {
			return 1;
		}
		return 0;
	}

}