/* * Copyright (c) 1999, 2004, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.naming; /**  * This class represents a Reference whose contents is a name, called the link name,  * that is bound to an atomic name in a context.  *<p>  * The name is a URL, or a name to be resolved relative to the initial  * context, or if the first character of the name is ".", the name  * is relative to the context in which the link is bound.  *<p>  * Normal resolution of names in context operations always follow links.  * Resolution of the link name itself may cause resolution to pass through  * other  links. This gives rise to the possibility of a cycle of links whose  * resolution could not terminate normally. As a simple means to avoid such  * non-terminating resolutions, service providers may define limits on the  * number of links that may be involved in any single operation invoked  * by the caller.  *<p>  * A LinkRef contains a single StringRefAddr, whose type is "LinkAddress",  * and whose contents is the link name. The class name field of the  * Reference is that of this (LinkRef) class.  *<p>  * LinkRef is bound to a name using the normal Context.bind()/rebind(), and  * DirContext.bind()/rebind(). Context.lookupLink() is used to retrieve the link  * itself if the terminal atomic name is bound to a link.  *<p>  * Many naming systems support a native notion of link that may be used  * within the naming system itself. JNDI does not specify whether  * there is any relationship between such native links and JNDI links.  *<p>  * A LinkRef instance is not synchronized against concurrent access by multiple  * threads. Threads that need to access a LinkRef instance concurrently should  * synchronize amongst themselves and provide the necessary locking.  *  * @author Rosanna Lee  * @author Scott Seligman  *  * @see LinkException  * @see LinkLoopException  * @see MalformedLinkException  * @see Context#lookupLink  * @since 1.3  */   /*<p>  * The serialized form of a LinkRef object consists of the serialized  * fields of its Reference superclass.  */ public class LinkRef extends Reference {    /* code for link handling */    static final String linkClassName = LinkRef.class.getName();    static final String linkAddrType = "LinkAddress";     /**      * Constructs a LinkRef for a name.      * @param linkName The non-null name for which to create this link.      */    public LinkRef(Name linkName) {        super(linkClassName, new StringRefAddr(linkAddrType, linkName.toString()));    }     /**      * Constructs a LinkRef for a string name.      * @param linkName The non-null name for which to create this link.      */    public LinkRef(String linkName) {        super(linkClassName, new StringRefAddr(linkAddrType, linkName));    }     /**      * Retrieves the name of this link.      *      * @return The non-null name of this link.      * @exception MalformedLinkException If a link name could not be extracted      * @exception NamingException If a naming exception was encountered.      */    public String getLinkName() throws NamingException {        if (className != null && className.equals(linkClassName)) {            RefAddr addr = get(linkAddrType);            if (addr != null && addr instanceof StringRefAddr) {                return (String)((StringRefAddr)addr).getContent();            }        }        throw new MalformedLinkException();    }    /**     * Use serialVersionUID from JNDI 1.1.1 for interoperability     */    private static final long serialVersionUID = -5386290613498931298L;}