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1   /*
2    * Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package java.awt;
27  
28  /**
29   * Thrown when code that is dependent on a keyboard, display, or mouse
30   * is called in an environment that does not support a keyboard, display,
31   * or mouse.
32   *
33   * @since 1.4
34   * @author  Michael Martak
35   */
36  public class HeadlessException extends UnsupportedOperationException {
37      /*
38       * JDK 1.4 serialVersionUID
39       */
40      private static final long serialVersionUID = 167183644944358563L;
41      public HeadlessException() {}
42      public HeadlessException(String msg) {
43          super(msg);
44      }
45      public String getMessage() {
46          String superMessage = super.getMessage();
47          String headlessMessage = GraphicsEnvironment.getHeadlessMessage();
48  
49          if (superMessage == null) {
50              return headlessMessage;
51          } else if (headlessMessage == null) {
52              return superMessage;
53          } else {
54              return superMessage + headlessMessage;
55          }
56      }
57  }