J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1999-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.naming.spi; |
| 27 | |
| 28 | import java.util.Hashtable; |
| 29 | import javax.naming.*; |
| 30 | import javax.naming.directory.Attributes; |
| 31 | |
| 32 | /** |
| 33 | * This interface represents a factory for creating an object given |
| 34 | * an object and attributes about the object. |
| 35 | *<p> |
| 36 | * The JNDI framework allows for object implementations to |
| 37 | * be loaded in dynamically via <em>object factories</em>. See |
| 38 | * <tt>ObjectFactory</tt> for details. |
| 39 | * <p> |
| 40 | * A <tt>DirObjectFactory</tt> extends <tt>ObjectFactory</tt> by allowing |
| 41 | * an <tt>Attributes</tt> instance |
| 42 | * to be supplied to the <tt>getObjectInstance()</tt> method. |
| 43 | * <tt>DirObjectFactory</tt> implementations are intended to be used by <tt>DirContext</tt> |
| 44 | * service providers. The service provider, in addition reading an |
| 45 | * object from the directory, might already have attributes that |
| 46 | * are useful for the object factory to check to see whether the |
| 47 | * factory is supposed to process the object. For instance, an LDAP-style |
| 48 | * service provider might have read the "objectclass" of the object. |
| 49 | * A CORBA object factory might be interested only in LDAP entries |
| 50 | * with "objectclass=corbaObject". By using the attributes supplied by |
| 51 | * the LDAP service provider, the CORBA object factory can quickly |
| 52 | * eliminate objects that it need not worry about, and non-CORBA object |
| 53 | * factories can quickly eliminate CORBA-related LDAP entries. |
| 54 | * |
| 55 | * @author Rosanna Lee |
| 56 | * @author Scott Seligman |
| 57 | * |
| 58 | * @see NamingManager#getObjectInstance |
| 59 | * @see DirectoryManager#getObjectInstance |
| 60 | * @see ObjectFactory |
| 61 | * @since 1.3 |
| 62 | */ |
| 63 | |
| 64 | public interface DirObjectFactory extends ObjectFactory { |
| 65 | /** |
| 66 | * Creates an object using the location or reference information, and attributes |
| 67 | * specified. |
| 68 | * <p> |
| 69 | * Special requirements of this object are supplied |
| 70 | * using <code>environment</code>. |
| 71 | * An example of such an environment property is user identity |
| 72 | * information. |
| 73 | *<p> |
| 74 | * <tt>DirectoryManager.getObjectInstance()</tt> |
| 75 | * successively loads in object factories. If it encounters a <tt>DirObjectFactory</tt>, |
| 76 | * it will invoke <tt>DirObjectFactory.getObjectInstance()</tt>; |
| 77 | * otherwise, it invokes |
| 78 | * <tt>ObjectFactory.getObjectInstance()</tt>. It does this until a factory |
| 79 | * produces a non-null answer. |
| 80 | * <p> When an exception |
| 81 | * is thrown by an object factory, the exception is passed on to the caller |
| 82 | * of <tt>DirectoryManager.getObjectInstance()</tt>. The search for other factories |
| 83 | * that may produce a non-null answer is halted. |
| 84 | * An object factory should only throw an exception if it is sure that |
| 85 | * it is the only intended factory and that no other object factories |
| 86 | * should be tried. |
| 87 | * If this factory cannot create an object using the arguments supplied, |
| 88 | * it should return null. |
| 89 | *<p>Since <tt>DirObjectFactory</tt> extends <tt>ObjectFactory</tt>, it |
| 90 | * effectively |
| 91 | * has two <tt>getObjectInstance()</tt> methods, where one differs from the other by |
| 92 | * the attributes argument. Given a factory that implements <tt>DirObjectFactory</tt>, |
| 93 | * <tt>DirectoryManager.getObjectInstance()</tt> will only |
| 94 | * use the method that accepts the attributes argument, while |
| 95 | * <tt>NamingManager.getObjectInstance()</tt> will only use the one that does not accept |
| 96 | * the attributes argument. |
| 97 | *<p> |
| 98 | * See <tt>ObjectFactory</tt> for a description URL context factories and other |
| 99 | * properties of object factories that apply equally to <tt>DirObjectFactory</tt>. |
| 100 | *<p> |
| 101 | * The <tt>name</tt>, <tt>attrs</tt>, and <tt>environment</tt> parameters |
| 102 | * are owned by the caller. |
| 103 | * The implementation will not modify these objects or keep references |
| 104 | * to them, although it may keep references to clones or copies. |
| 105 | * |
| 106 | * @param obj The possibly null object containing location or reference |
| 107 | * information that can be used in creating an object. |
| 108 | * @param name The name of this object relative to <code>nameCtx</code>, |
| 109 | * or null if no name is specified. |
| 110 | * @param nameCtx The context relative to which the <code>name</code> |
| 111 | * parameter is specified, or null if <code>name</code> is |
| 112 | * relative to the default initial context. |
| 113 | * @param environment The possibly null environment that is used in |
| 114 | * creating the object. |
| 115 | * @param attrs The possibly null attributes containing some of <tt>obj</tt>'s |
| 116 | * attributes. <tt>attrs</tt> might not necessarily have all of <tt>obj</tt>'s |
| 117 | * attributes. If the object factory requires more attributes, it needs |
| 118 | * to get it, either using <tt>obj</tt>, or <tt>name</tt> and <tt>nameCtx</tt>. |
| 119 | * The factory must not modify attrs. |
| 120 | * @return The object created; null if an object cannot be created. |
| 121 | * @exception Exception If this object factory encountered an exception |
| 122 | * while attempting to create an object, and no other object factories are |
| 123 | * to be tried. |
| 124 | * |
| 125 | * @see DirectoryManager#getObjectInstance |
| 126 | * @see NamingManager#getURLContext |
| 127 | */ |
| 128 | public Object getObjectInstance(Object obj, Name name, Context nameCtx, |
| 129 | Hashtable<?,?> environment, |
| 130 | Attributes attrs) |
| 131 | throws Exception; |
| 132 | } |