1 /* 2 * Copyright (c) 2000, 2014, 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 42 /** 43 * Constructs new {@code HeadlessException} 44 */ 45 public HeadlessException() {} 46 47 /** 48 * Create a new instance with the specified detailed error message. 49 * 50 * @param msg the error message 51 */ 52 public HeadlessException(String msg) { 53 super(msg); 54 } 55 56 /** 57 * {@inheritDoc} 58 */ 59 public String getMessage() { 60 String superMessage = super.getMessage(); 61 String headlessMessage = GraphicsEnvironment.getHeadlessMessage(); 62 63 if (superMessage == null) { 64 return headlessMessage; 65 } else if (headlessMessage == null) { 66 return superMessage; 67 } else { 68 return superMessage + headlessMessage; 69 } 70 } 71 }