| /* |
| * Copyright (c) 2000, 2016, Oracle and/or its affiliates. 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.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. Any code that depends on any of those devices should firstly |
| * ensure their availability using the {@code GraphicsEnvironment.isHeadless()} |
| * method and throw {@code HeadlessException} if the latter returns |
| * {@code true}. |
| * |
| * @since 1.4 |
| * @author Michael Martak |
| * @see GraphicsEnvironment#isHeadless |
| */ |
| public class HeadlessException extends UnsupportedOperationException { |
| /* |
| * JDK 1.4 serialVersionUID |
| */ |
| private static final long serialVersionUID = 167183644944358563L; |
| |
| /** |
| * Constructs new {@code HeadlessException} with empty message. |
| * For such {@code HeadlessException} the default headless error message |
| * may be auto-generated for some platforms. |
| * The text of the default headless message may depend on |
| * whether the GraphicsEnvironment is in fact headless. |
| * That is, the default headless message is both system and environmentally |
| * dependent. |
| */ |
| public HeadlessException() {} |
| |
| /** |
| * Create a new instance with the specified detailed error message. |
| * For some platforms the default headless error message may be |
| * added at the end of the specified message. |
| * The text of the default headless message may depend on |
| * whether the GraphicsEnvironment is in fact headless. |
| * That is, the default headless message is both system and environmentally |
| * dependent. |
| * |
| * @param msg the error message |
| */ |
| public HeadlessException(String msg) { |
| super(msg); |
| } |
| |
| /** |
| * Returns the detail message string of this {@code HeadlessException}. |
| * Depending on the platform the message specified in the constructor may |
| * be followed by the default headless error message. |
| * The text of the default headless message may depend on |
| * whether the GraphicsEnvironment is in fact headless. |
| * That is, the default headless message is both system and environmentally |
| * dependent. |
| * |
| * @return the detail message string of this {@code HeadlessException} |
| * instance (which may be {@code null}). |
| */ |
| 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; |
| } |
| } |
| } |