/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
package com.sun.enterprise.security.auth.realm;

import java.security.Principal;

import java.util.Enumeration;


/**
 * All users are principals ... perhaps in the native OS, perhaps
 * not.
 *
 * <P> Users always have authentication information, which is used
 * to validate a user's proferred credentials.  Different kinds of
 * realms use different kinds of authentication information.  For
 * example, realms could use X.509 public key certificates, shared
 * passphrases, encrypted passwords, smart cards, or biometric data
 * to figure out if the user's credentials are valid.
 * 
 * <P> Users typically have attributes that identify privileges 
 * granted/possesed by the user.
 *
 * @author Harish Prabandham
 */

public interface User extends Principal {
    /**
     * Returns the realm with which this user is associated.
     */
    Realm getRealm () throws NoSuchRealmException;


    /**
     * Returns the single requested attribute for the user.
     *
     * @param name string identifying the attribute.
     * @return value of that attribute, or null if no value
     *	has been defined
     */
    Object getAttribute (String name);


    /**
     * Returns an enumeration of the keys for the attributes
     * supported for this user.
     */
    Enumeration	getAttributeNames ();
}