001    /*
002     * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
003     *
004     * The Apache Software License, Version 1.1
005     *
006     * Redistribution and use in source and binary forms, with or without
007     * modification, are permitted provided that the following conditions
008     * are met:
009     *
010     * 1. Redistributions of source code must retain the above copyright
011     *    notice, this list of conditions and the following disclaimer.
012     *
013     * 2. Redistributions in binary form must reproduce the above copyright
014     *    notice, this list of conditions and the following disclaimer in
015     *    the documentation and/or other materials provided with the
016     *    distribution.
017     *
018     * 3. The end-user documentation included with the redistribution, if
019     *    any, must include the following acknowlegement:
020     *       "This product includes software developed by the
021     *        Caucho Technology (http://www.caucho.com/)."
022     *    Alternately, this acknowlegement may appear in the software itself,
023     *    if and wherever such third-party acknowlegements normally appear.
024     *
025     * 4. The names "Burlap", "Hessian", "Resin", and "Caucho" must not be
026     *    used to endorse or promote products derived from this software
027     *    without prior written permission. For written permission, please contact
028     *    info@caucho.com.
029     *
030     * 5. Products derived from this software may not be called "Resin"
031     *    nor may "Resin" appear in their names without prior written
032     *    permission of Caucho Technology.
033     *
034     * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
035     * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
036     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
037     * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
038     * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
039     * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
040     * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
041     * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
042     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
043     * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
044     * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
045     *
046     * @author Scott Ferguson
047     */
048    
049    package com.caucho.services.name;
050    
051    import java.rmi.RemoteException;
052    
053    /**
054     * A read-only name service.  The name service provides hierarchical
055     * object lookup.  The path names are separated by '/'.
056     *
057     * <p>Because the name service is hierarchical, a lookup of an intermediate
058     * node will return a NameServer instance.
059     *
060     * <p>The following example is a simple use of the NameServer:
061     * <pre>
062     * /dir-1/1 - where foo contains the string "foo-1"
063     * /dir-1/2 - where foo contains the string "foo-2"
064     * /dir-2/1 - where foo contains the string "foo-1"
065     * /dir-2/2 - where foo contains the string "foo-2"
066     * </pre>
067     *
068     * <p/>The root server might have a URL like:
069     * <pre>
070     * http://www.caucho.com/hessian/hessian/name?ejbid=/
071     * </pre>
072     *
073     * <p/>So <code>root.lookup("/dir-1/1")</code> will return the string
074     * "foo-1", and <code>root.lookup("/dir-1")</code> will return the
075     * NameServer with the URL:
076     * <pre>
077     * http://www.caucho.com/hessian/hessian/name?ejbid=/dir-1
078     * </pre>
079     */
080    public interface NameServerRemote {
081      /**
082       * Lookup an object from the name server.
083       *
084       * @param name the relative path name
085       *
086       * @return the matching object or null if no object maches
087       *
088       * @exception NameServiceException if there's an error
089       */
090      public Object lookup(String name)
091        throws NameServiceException, RemoteException;
092    
093      /**
094       * Lists all the object name components directly below the current context.
095       * The names are the relative compent name.
096       *
097       * <p>For example, if the name server context is "/dir-1", the returned
098       * values will be ["1", "2"].
099       */
100      public String []list()
101        throws NameServiceException, RemoteException;
102    }