/* * 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.spi; import javax.naming.*;import java.util.Hashtable; /**  * This interface represents a factory for obtaining the state of an  * object for binding.  *<p>  * The JNDI framework allows for object implementations to  * be loaded in dynamically via <em>object factories</em>.  * For example, when looking up a printer bound in the name space,  * if the print service binds printer names to <tt>Reference</tt>s, the printer  * <tt>Reference</tt> could be used to create a printer object, so that  * the caller of lookup can directly operate on the printer object  * after the lookup.  * <p>An <tt>ObjectFactory</tt> is responsible  * for creating objects of a specific type.  In the above example,  * you may have a <tt>PrinterObjectFactory</tt> for creating  * <tt>Printer</tt> objects.  * <p>  * For the reverse process, when an object is bound into the namespace,  * JNDI provides <em>state factories</em>.  * Continuing with the printer example, suppose the printer object is  * updated and rebound:  * <blockquote><pre>  * ctx.rebind("inky", printer);  * </pre></blockquote>  * The service provider for <tt>ctx</tt> uses a state factory  * to obtain the state of <tt>printer</tt> for binding into its namespace.  * A state factory for the <tt>Printer</tt> type object might return  * a more compact object for storage in the naming system.  *<p>  * A state factory must implement the <tt>StateFactory</tt> interface.  * In addition, the factory class must be public and must have a  * public constructor that accepts no parameters.  *<p>  * The <tt>getStateToBind()</tt> method of a state factory may  * be invoked multiple times, possibly using different parameters.  * The implementation is thread-safe.  *<p>  * <tt>StateFactory</tt> is intended for use with service providers  * that implement only the <tt>Context</tt> interface.  * <tt>DirStateFactory</tt> is intended for use with service providers  * that implement the <tt>DirContext</tt> interface.  *  * @author Rosanna Lee  * @author Scott Seligman  *  * @see NamingManager#getStateToBind  * @see DirectoryManager#getStateToBind  * @see ObjectFactory  * @see DirStateFactory  * @since 1.3  */public interface StateFactory {/** * Retrieves the state of an object for binding. *<p> * <tt>NamingManager.getStateToBind()</tt> * successively loads in state factories and invokes this method * on them until one produces a non-null answer. * <tt>DirectoryManager.getStateToBind()</tt> * successively loads in state factories.  If a factory implements * <tt>DirStateFactory</tt>, then <tt>DirectoryManager</tt> * invokes <tt>DirStateFactory.getStateToBind()</tt>; otherwise * it invokes <tt>StateFactory.getStateToBind()</tt>. *<p> When an exception * is thrown by a factory, the exception is passed on to the caller * of <tt>NamingManager.getStateToBind()</tt> and * <tt>DirectoryManager.getStateToBind()</tt>. * The search for other factories * that may produce a non-null answer is halted. * A factory should only throw an exception if it is sure that * it is the only intended factory and that no other factories * should be tried. * If this factory cannot create an object using the arguments supplied, * it should return null. * <p> * The <code>name</code> and <code>nameCtx</code> parameters may * optionally be used to specify the name of the object being created. * See the description of "Name and Context Parameters" in * {@link ObjectFactory#getObjectInstance ObjectFactory.getObjectInstance()} * for details. * If a factory uses <code>nameCtx</code> it should synchronize its use * against concurrent access, since context implementations are not * guaranteed to be thread-safe. * <p> * The <tt>name</tt> and <tt>environment</tt> parameters * are owned by the caller. * The implementation will not modify these objects or keep references * to them, although it may keep references to clones or copies. * * @param obj A non-null object whose state is to be retrieved. * @param name The name of this object relative to <code>nameCtx</code>, *              or null if no name is specified. * @param nameCtx The context relative to which the <code>name</code> *              parameter is specified, or null if <code>name</code> is *              relative to the default initial context. * @param environment The possibly null environment to *              be used in the creation of the object's state. * @return The object's state for binding; *              null if the factory is not returning any changes. * @exception NamingException if this factory encountered an exception * while attempting to get the object's state, and no other factories are * to be tried. * * @see NamingManager#getStateToBind * @see DirectoryManager#getStateToBind */    public Object getStateToBind(Object obj, Name name, Context nameCtx,                                 Hashtable<?,?> environment)        throws NamingException;}