/*
 * Copyright 2000-2004 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package java.awt;

/**
 * Thrown when code that is dependent on a keyboard, display, or mouse
 * is called in an environment that does not support a keyboard, display,
 * or mouse.
 *
 * @since 1.4
 * @author  Michael Martak
 */
public class HeadlessException extends UnsupportedOperationException {
    /*
     * JDK 1.4 serialVersionUID
     */
    private static final long serialVersionUID = 167183644944358563L;
    public HeadlessException() {}
    public HeadlessException(String msg) {
        super(msg);
    }
    public String getMessage() {
        String superMessage = super.getMessage();
        String headlessMessage = GraphicsEnvironment.getHeadlessMessage();

        if (superMessage == null) {
            return headlessMessage;
        } else if (headlessMessage == null) {
            return superMessage;
        } else {
            return superMessage + headlessMessage;
        }
    }
}