Trivial.java

/*******************************************************************************
 * Copyright (c) 2004, 2006
 * Thomas Hallgren, Kenneth Olwing, Mitch Sonies
 * Pontus Rydin, Nils Unden, Peer Torngren
 * The code, documentation and other materials contained herein have been
 * licensed under the Eclipse Public License - v 1.0 by the individual
 * copyright holders listed above, as Initial Contributors under such license.
 * The text of such license is available at www.eclipse.org.
 *******************************************************************************/
package org.eclipse.buckminster.runtime;

import java.net.URL;

import org.eclipse.core.runtime.IPath;

public class Trivial {
	public static final Class<?>[] EMPTY_CLASS_ARRAY = new Class[0];

	public static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];

	public static final String[] EMPTY_STRING_ARRAY = new String[0];

	public static final IPath[] EMPTY_PATH_ARRAY = new IPath[0];

	public static final URL[] EMPTY_URL_ARRAY = new URL[0];

	public static <T extends Comparable<T>> int compareAllowNull(T a, T b) {
		return a == null ? (b == null ? 0 : -1) : (b == null ? 1 : a.compareTo(b));
	}

	public static boolean equalsAllowNull(Object a, Object b) {
		return a == null ? b == null : a.equals(b);
	}

	/**
	 * If <code>str</code> is <code>null</code> or if the result of a trim on
	 * <code>str</code> is a string of zero length, then <code>null</code> is
	 * returned, otherwise, trimmed string is returned.
	 * 
	 * @param str
	 *            The string to trim. Can be <code>null</code>.
	 * @return A trimmed string with a length greater then zero or
	 *         <code>null</code>.
	 */
	public static String trim(String str) {
		if (str != null) {
			str = str.trim();
			if (str.length() == 0)
				str = null;
		}
		return str;
	}
}