CollectionUtils.java

/**
 * Mad-Advertisement
 * Copyright (C) 2011 Thorsten Marx <thmarx@gmx.net>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */
package net.mad.ads.common.util;

import java.util.ArrayList;
import java.util.Collection;

public class CollectionUtils {
	public interface Predicate<T> { boolean apply(T type); }
	
	public static <T> Collection<T> filter(Collection<T> target, Predicate<T> predicate) {
		if (predicate == null) {
			return target;
		}
		if (target == null || target.isEmpty()) {
			return target;
		}
	    Collection<T> result = new ArrayList<T>();
	    for (T element: target) {
	        if (predicate.apply(element)) {
	            result.add(element);
	        }
	    }
	    return result;
	}
}