001/* Callback.java -- marker interface for callback classes 002 Copyright (C) 2003, Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package javax.security.auth.callback; 040 041/** 042 * <p>Implementations of this interface are passed to a {@link CallbackHandler}, 043 * allowing underlying security services the ability to interact with a calling 044 * application to retrieve specific authentication data such as usernames and 045 * passwords, or to display certain information, such as error and warning 046 * messages.</p> 047 * 048 * <p><code>Callback</code> implementations do not retrieve or display the 049 * information requested by underlying security services. <code>Callback</code> 050 * implementations simply provide the means to pass such requests to 051 * applications, and for applications, if appropriate, to return requested 052 * information back to the underlying security services.</p> 053 * 054 * @see CallbackHandler 055 * @see ChoiceCallback 056 * @see ConfirmationCallback 057 * @see LanguageCallback 058 * @see NameCallback 059 * @see PasswordCallback 060 * @see TextInputCallback 061 * @see TextOutputCallback 062 */ 063public interface Callback { 064}