/* * 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. *
* The JNDI framework allows for object implementations to * be loaded in dynamically via object factories. See * {@code ObjectFactory} for details. *
* A {@code DirObjectFactory} extends {@code ObjectFactory} by allowing * an {@code Attributes} instance * to be supplied to the {@code getObjectInstance()} method. * {@code DirObjectFactory} implementations are intended to be used by {@code DirContext} * 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. *
* Special requirements of this object are supplied
* using environment
.
* An example of such an environment property is user identity
* information.
*
* {@code DirectoryManager.getObjectInstance()} * successively loads in object factories. If it encounters a {@code DirObjectFactory}, * it will invoke {@code DirObjectFactory.getObjectInstance()}; * otherwise, it invokes * {@code ObjectFactory.getObjectInstance()}. It does this until a factory * produces a non-null answer. *
When an exception * is thrown by an object factory, the exception is passed on to the caller * of {@code DirectoryManager.getObjectInstance()}. 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. *
Since {@code DirObjectFactory} extends {@code ObjectFactory}, it * effectively * has two {@code getObjectInstance()} methods, where one differs from the other by * the attributes argument. Given a factory that implements {@code DirObjectFactory}, * {@code DirectoryManager.getObjectInstance()} will only * use the method that accepts the attributes argument, while * {@code NamingManager.getObjectInstance()} will only use the one that does not accept * the attributes argument. *
* See {@code ObjectFactory} for a description URL context factories and other * properties of object factories that apply equally to {@code DirObjectFactory}. *
* The {@code name}, {@code attrs}, and {@code environment} 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 nameCtx
,
* or null if no name is specified.
* @param nameCtx The context relative to which the name
* parameter is specified, or null if name
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 {@code obj}'s
* attributes. {@code attrs} might not necessarily have all of {@code obj}'s
* attributes. If the object factory requires more attributes, it needs
* to get it, either using {@code obj}, or {@code name} and {@code nameCtx}.
* 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;
}