/* * 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 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * 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: ResolverService.java,v 1.9 2003/03/06 18:37:45 bondolo Exp $ */package net.jxta.resolver;import net.jxta.service.Service;/** * ResolverService provides a generic mechanism for JXTA Services * to send "Queries", and receive "Responses".  It removes the burden for * registered handlers in deal with : * *<ul type-disc> *    <li><p>Setting message tags, to ensure uniqueness of tags and *     ensures that messages are sent to the correct address, and group *    <li><p>Authentication, and Verification of credentials *    <li><p>drop rogue messages *</ul> * * <p/>The ResolverService does not proccess the queries, nor does it not compose * reponses. Handling of queries, and composition of responses are left up * to the registered handlers. Services that wish to handle queries, * and generate reponses must implement {@link net.jxta.resolver.QueryHandler} * * <p/>Message Format: * * <ul><li>A Query message: * * <pre>&lt;?xml version="1.0" standalone='yes'?&gt; * &lt;ResolverQuery&gt; *   &lt;handlername&gt; name &lt;/handlername&gt; *   &lt;credentialServiecUri&gt; uri &lt;/credentialServiecUri&gt; *   &lt;credentialToken&gt; token &lt;/credentialToken&gt; *   &lt;srcpeerid&gt; srcpeerid &lt;/srcpeerid&gt; *   &lt;queryid&gt; id &lt;/queryid&gt; *   &lt;query&gt; query &lt;/query&gt; * &lt;/ResolverQuery&gt;</pre> * * <p/>Note: queryid is unique to the originating node only, it can be utilized to * match queries to responses.</p></li> * * <li>A Response Message: * * <pre>&lt;?xml version="1.0" standalone='yes'?&gt; * &lt;ResolverResponse&gt; *   &lt;handlername&gt; name &lt;/handlername&gt; *   &lt;credentialServiecUri&gt; uri &lt;/credentialServiecUri&gt; *   &lt;credentialToken&gt; token &lt;/credentialToken&gt; *   &lt;queryid&gt; id &lt;/queryid&gt; *   &lt;response&gt; response &lt;/response&gt; * &lt;/ResolverResponse&gt;</pre> * * <p/>Note: queryid is unique to the originating node only, it can be * utilized to match queries to responses.</li></ul> * * @see net.jxta.service.Service * @see net.jxta.resolver.GenericResolver * @see net.jxta.resolver.QueryHandler * @see net.jxta.protocol.ResolverQueryMsg * @see net.jxta.protocol.ResolverResponseMsg * **/public interface ResolverService extends Service, GenericResolver {    /**     *  Returned by query handlers to indicate that the query should be     *  forwarded to the rest of the network.     **/    public final static int Repropagate = -1;        /**     *  Returned by query handlers to indicate that the query has been resolved     *  and a response has been sent.     **/    public final static int OK = 0;        /**     * Registers a given ResolveHandler, returns the previous handler registered under this name     *     * @param name The name under which this handler is to be registered.     * @param handler The handler.     * @return The previous handler registered under this name          *     */    public QueryHandler registerHandler( String name, QueryHandler handler );   /**     * unregisters a given ResolveHandler, returns the previous handler registered under this name     *     * @param name The name of the handler to unregister.     * @return The previous handler registered under this name          *     */        public QueryHandler unregisterHandler( String name );    /**     * Registers a given SrdiHandler, returns the previous handler registered under this name      *     * @param name The name under which this handler is to be registered.     * @param handler The handler.     * @return The previous handler registered under this name          *     */    public SrdiHandler registerSrdiHandler( String name, SrdiHandler handler );    /**     * unregisters a given SrdiHandler, returns the previous handler registered under this name     *     * @param name The name of the handler to unregister.     * @return The previous handler registered under this name     *     */        public SrdiHandler unregisterSrdiHandler( String name );}