001 /* Callback.java -- marker interface for callback classes 002 Copyright (C) 2003, Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package 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 */ 063 public interface Callback { 064 }