membershipservice.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

/*
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" 
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: MembershipService.java,v 1.7 2006/01/13 22:40:34 bondolo Exp $
 */

package net.jxta.membership;

import java.beans.PropertyChangeListener;
import java.util.Enumeration;

import net.jxta.credential.AuthenticationCredential;
import net.jxta.credential.Credential;
import net.jxta.document.Element;
import net.jxta.service.Service;

import net.jxta.exception.PeerGroupException;
import net.jxta.exception.ProtocolNotSupportedException;

/**
 *  Allows a peer to establish an identity within a peer group. Identities are 
 *  used by services and applications to determine the capabilities available to 
 *  peers. A peer have any number of identities at one time. Once an identity 
 *  has been established a Credential object is available which allows the peer 
 *  to prove that it rightfully has that identity.
 *
 *  <p/>The sequence for associating an indentity with a peer within a peer
 *  group is as follows:
 *
 * <p/><table>
 *  <tr><td valign="top"><b>Apply</b></td>
 * <td>An application or service provides the membership service with an
 * initial credential which may be used by the membership service to determine
 *  the method of authentication to be used for establishing the identity.
 * If the membership service implementations allows authentication using the
 * requested mechanism then an {@link Authenticator} object is returned.
 * </td></tr>
 *
 *  <tr><td valign="top"><b>Join</b></td>
 * <td>The application or service completes the authenticator. This may involve
 * presenting a user interface, completing challenges, etc. How the
 * authenticator is completed depends on the type of membership service and
 * authenticator in use.
 *
 * <p/>Once completed, the authenticator is returned to the membership service.
 * If the authenticator has been correctly completed, a new credential for the
 * new identity will be available to the peer from the membership service.
 * </td></tr>
 *
 *  <tr><td valign="top"><b>Resign</b></td>
 * <td>Whenever the application or service no longer wishes to no longer use the
 * identities it has claimed, it may resign from the peergroup. This will cause
 * any identity credentials held by the membership service to  discarded.
 * </td></tr>
 *  </table>
 *
 *  @see net.jxta.credential.Credential
 *  @see net.jxta.credential.AuthenticationCredential
 *
 **/
public interface MembershipService extends Service {
    
    /**
     *  Property name for the default credential bound property.
     **/
    public final static String DEFAULT_CREDENTIAL_PROPERTY = "defaultCredential";
    
    /**
     *  Property name for credential addition bound property.
     **/
    public final static String ADD_CREDENTIAL_PROPERTY = "addCredential";
    
    /**
     * Request the necessary credentials to join the group with which this
     * service is associated.
     *
     * @param application The authentication Credential associated with this
     * membership application. See
     * {@link net.jxta.credential.AuthenticationCredential}
     * for more information.
     * @return An Authenticator for the membership service.
     *
     * @throws PeerGroupException Thrown in the event of errors.
     * @throws ProtocolNotSupportedException if the authentication method requested
     *       in the application is not supported by this service.
     **/
    public Authenticator apply( AuthenticationCredential application ) throws PeerGroupException, ProtocolNotSupportedException;
    
    /**
     * Join the group by virtue of the completed authentication provided.
     *
     * @param authenticated the completed authentication.
     * @return Credential the credential for this completed authentication.
     * @throws PeerGroupException Thrown in the event of errors.
     **/
    public Credential join(Authenticator authenticated ) throws PeerGroupException;
    
    /**
     * Resign all credentials which were previously gained through prior
     * {@link #join(Authenticator) join()} operations.
     *
     * @throws PeerGroupException Thrown in the event of errors. 
     **/
    public void resign() throws PeerGroupException;
    
    /**
     *  Returns the default credential for this peer.
     *
     *  @return The current default Credential or {@code null} if there is no
     *  current default.
     *  @throws PeerGroupException Thrown in the event of errors.
     **/
    public Credential getDefaultCredential() throws PeerGroupException;
    
    /**
     * Returns the current credentials for this peer. The elements of the
     * enumeration are all of types derived from "Credential". Before
     * {@link #join(Authenticator) join()} or after {@link #resign()} are called, this
     * enumeration will consist of a single element, a default credential
     * which is usually has the identity "nobody". This credential always
     * exists, but likely offers few, if any, privledges within this group.
     *
     * @return Enumeration of the Credentials currently associated with this
     * peer for this peergroup.
     * @throws PeerGroupException Thrown in the event of errors.
     **/
    public Enumeration getCurrentCredentials() throws PeerGroupException;
    
    /**
     * Returns the current credentials for this peer. The elements of the
     * enumeration are all of types derived from
     * {@link net.jxta.credential.AuthenticationCredential}
     *
     * @return Enumeration of the AuthenticationCredentials which were used to
     * establish the current identities.
     * @throws PeerGroupException Thrown in the event of errors.
     **/
    public Enumeration getAuthCredentials() throws PeerGroupException;
    
    /**
     * Given a fragment of a StructuredDocument, reconstruct a Credential object
     * from that fragment.
     *
     * @return Credential The created credential
     * @param element The StructuredDocument fragment to use for building the
     * credential.
     * @throws PeerGroupException Thrown in the event of errors.
     * @throws Exception Thrown in the event of errors.
     **/
    public Credential makeCredential( Element element ) throws PeerGroupException, Exception;
    
    /**
     *  Add a listener
     *
     *  @param listener the listener
     **/
    public void addPropertyChangeListener( PropertyChangeListener listener );
    
    /**
     *  Add a listener. Available properties from all Membership Services are : 
     *      
     *      <p/><ul>
     *          <li>{@code defaultCredential}</li>
     *          <li>{@code addCredential}</li>
     *      </ul>
     *
     *  <p/>Membership Services may offer additional properties.
     *
     *  @param propertyName The property to watch
     *  @param listener The listener
     **/
    public void addPropertyChangeListener( String propertyName, PropertyChangeListener listener );
    
    /**
     *  Remove a listener
     *
     *  @param listener the listener
     **/
    public void removePropertyChangeListener( PropertyChangeListener listener );
    
    /**
     *  Remove a listener
     *
     *  @param propertyName the property which was watched
     *  @param listener the listener
     **/
    public void removePropertyChangeListener( String propertyName, PropertyChangeListener listener );
}