/* * 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 java.util.Hashtable;import javax.naming.*;import javax.naming.directory.Attributes; /**  * This interface represents a factory for creating an object given  * an object and attributes about the object.  *<p>  * The JNDI framework allows for object implementations to  * be loaded in dynamically via <em>object factories</em>. See  * <tt>ObjectFactory</tt> for details.  * <p>  * A <tt>DirObjectFactory</tt> extends <tt>ObjectFactory</tt> by allowing  * an <tt>Attributes</tt> instance  * to be supplied to the <tt>getObjectInstance()</tt> method.  * <tt>DirObjectFactory</tt> implementations are intended to be used by <tt>DirContext</tt>  * service providers. The service provider, in addition reading an  * object from the directory, might already have attributes that  * are useful for the object factory to check to see whether the  * factory is supposed to process the object. For instance, an LDAP-style  * service provider might have read the "objectclass" of the object.  * A CORBA object factory might be interested only in LDAP entries  * with "objectclass=corbaObject". By using the attributes supplied by  * the LDAP service provider, the CORBA object factory can quickly  * eliminate objects that it need not worry about, and non-CORBA object  * factories can quickly eliminate CORBA-related LDAP entries.  *  * @author Rosanna Lee  * @author Scott Seligman  *  * @see NamingManager#getObjectInstance  * @see DirectoryManager#getObjectInstance  * @see ObjectFactory  * @since 1.3  */ public interface DirObjectFactory extends ObjectFactory {/** * Creates an object using the location or reference information, and attributes * specified. * <p> * Special requirements of this object are supplied * using <code>environment</code>. * An example of such an environment property is user identity * information. *<p> * <tt>DirectoryManager.getObjectInstance()</tt> * successively loads in object factories. If it encounters a <tt>DirObjectFactory</tt>, * it will invoke <tt>DirObjectFactory.getObjectInstance()</tt>; * otherwise, it invokes * <tt>ObjectFactory.getObjectInstance()</tt>. It does this until a factory * produces a non-null answer. * <p> When an exception * is thrown by an object factory, the exception is passed on to the caller * of <tt>DirectoryManager.getObjectInstance()</tt>. The search for other factories * that may produce a non-null answer is halted. * An object factory should only throw an exception if it is sure that * it is the only intended factory and that no other object factories * should be tried. * If this factory cannot create an object using the arguments supplied, * it should return null.  *<p>Since <tt>DirObjectFactory</tt> extends <tt>ObjectFactory</tt>, it  * effectively  * has two <tt>getObjectInstance()</tt> methods, where one differs from the other by  * the attributes argument. Given a factory that implements <tt>DirObjectFactory</tt>,  * <tt>DirectoryManager.getObjectInstance()</tt> will only  * use the method that accepts the attributes argument, while  * <tt>NamingManager.getObjectInstance()</tt> will only use the one that does not accept  * the attributes argument. *<p> * See <tt>ObjectFactory</tt> for a description URL context factories and other * properties of object factories that apply equally to <tt>DirObjectFactory</tt>. *<p> * The <tt>name</tt>, <tt>attrs</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 The possibly null object containing location or reference *              information that can be used in creating an object. * @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 that is used in *              creating the object. * @param attrs The possibly null attributes containing some of <tt>obj</tt>'s * attributes. <tt>attrs</tt> might not necessarily have all of <tt>obj</tt>'s * attributes. If the object factory requires more attributes, it needs * to get it, either using <tt>obj</tt>, or <tt>name</tt> and <tt>nameCtx</tt>. *      The factory must not modify attrs. * @return The object created; null if an object cannot be created. * @exception Exception If this object factory encountered an exception * while attempting to create an object, and no other object factories are * to be tried. * * @see DirectoryManager#getObjectInstance * @see NamingManager#getURLContext */    public Object getObjectInstance(Object obj, Name name, Context nameCtx,                                    Hashtable<?,?> environment,                                    Attributes attrs)        throws Exception;}