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 package javax.naming.spi;
26
27 import javax.naming;
28 import javax.naming.directory.Attributes;
29 import java.util.Hashtable;
30
31 /**
32 * This interface represents a factory for obtaining the state of an
33 * object and corresponding attributes for binding.
34 *<p>
35 * The JNDI framework allows for object implementations to
36 * be loaded in dynamically via <tt>object factories</tt>.
37 * <p>
38 * A <tt>DirStateFactory</tt> extends <tt>StateFactory</tt>
39 * by allowing an <tt>Attributes</tt> instance
40 * to be supplied to and be returned by the <tt>getStateToBind()</tt> method.
41 * <tt>DirStateFactory</tt> implementations are intended to be used by
42 * <tt>DirContext</tt> service providers.
43 * When a caller binds an object using <tt>DirContext.bind()</tt>,
44 * he might also specify a set of attributes to be bound with the object.
45 * The object and attributes to be bound are passed to
46 * the <tt>getStateToBind()</tt> method of a factory.
47 * If the factory processes the object and attributes, it returns
48 * a corresponding pair of object and attributes to be bound.
49 * If the factory does not process the object, it must return null.
50 *<p>
51 * For example, a caller might bind a printer object with some printer-related
52 * attributes.
53 *<blockquote><pre>
54 * ctx.rebind("inky", printer, printerAttrs);
55 *</pre></blockquote>
56 * An LDAP service provider for <tt>ctx</tt> uses a <tt>DirStateFactory</tt>
57 * (indirectly via <tt>DirectoryManager.getStateToBind()</tt>)
58 * and gives it <tt>printer</tt> and <tt>printerAttrs</tt>. A factory for
59 * an LDAP directory might turn <tt>printer</tt> into a set of attributes
60 * and merge that with <tt>printerAttrs</tt>. The service provider then
61 * uses the resulting attributes to create an LDAP entry and updates
62 * the directory.
63 *
64 * <p> Since <tt>DirStateFactory</tt> extends <tt>StateFactory</tt>, it
65 * has two <tt>getStateToBind()</tt> methods, where one
66 * differs from the other by the attributes
67 * argument. <tt>DirectoryManager.getStateToBind()</tt> will only use
68 * the form that accepts the attributes argument, while
69 * <tt>NamingManager.getStateToBind()</tt> will only use the form that
70 * does not accept the attributes argument.
71 *
72 * <p> Either form of the <tt>getStateToBind()</tt> method of a
73 * DirStateFactory may be invoked multiple times, possibly using different
74 * parameters. The implementation is thread-safe.
75 *
76 * @author Rosanna Lee
77 * @author Scott Seligman
78 *
79 * @see DirectoryManager#getStateToBind
80 * @see DirObjectFactory
81 * @since 1.3
82 */
83 public interface DirStateFactory extends StateFactory {
84 /**
85 * Retrieves the state of an object for binding given the object and attributes
86 * to be transformed.
87 *<p>
88 * <tt>DirectoryManager.getStateToBind()</tt>
89 * successively loads in state factories. If a factory implements
90 * <tt>DirStateFactory</tt>, <tt>DirectoryManager</tt> invokes this method;
91 * otherwise, it invokes <tt>StateFactory.getStateToBind()</tt>.
92 * It does this until a factory produces a non-null answer.
93 *<p>
94 * When an exception is thrown by a factory,
95 * the exception is passed on to the caller
96 * of <tt>DirectoryManager.getStateToBind()</tt>. The search for other factories
97 * that may produce a non-null answer is halted.
98 * A factory should only throw an exception if it is sure that
99 * it is the only intended factory and that no other factories
100 * should be tried.
101 * If this factory cannot create an object using the arguments supplied,
102 * it should return null.
103 * <p>
104 * The <code>name</code> and <code>nameCtx</code> parameters may
105 * optionally be used to specify the name of the object being created.
106 * See the description of "Name and Context Parameters" in
107 * {@link ObjectFactory#getObjectInstance ObjectFactory.getObjectInstance()}
108 * for details.
109 * If a factory uses <code>nameCtx</code> it should synchronize its use
110 * against concurrent access, since context implementations are not
111 * guaranteed to be thread-safe.
112 *<p>
113 * The <tt>name</tt>, <tt>inAttrs</tt>, and <tt>environment</tt> parameters
114 * are owned by the caller.
115 * The implementation will not modify these objects or keep references
116 * to them, although it may keep references to clones or copies.
117 * The object returned by this method is owned by the caller.
118 * The implementation will not subsequently modify it.
119 * It will contain either a new <tt>Attributes</tt> object that is
120 * likewise owned by the caller, or a reference to the original
121 * <tt>inAttrs</tt> parameter.
122 *
123 * @param obj A possibly null object whose state is to be retrieved.
124 * @param name The name of this object relative to <code>nameCtx</code>,
125 * or null if no name is specified.
126 * @param nameCtx The context relative to which the <code>name</code>
127 * parameter is specified, or null if <code>name</code> is
128 * relative to the default initial context.
129 * @param environment The possibly null environment to
130 * be used in the creation of the object's state.
131 * @param inAttrs The possibly null attributes to be bound with the object.
132 * The factory must not modify <tt>inAttrs</tt>.
133 * @return A <tt>Result</tt> containing the object's state for binding
134 * and the corresponding
135 * attributes to be bound; null if the object don't use this factory.
136 * @exception NamingException If this factory encountered an exception
137 * while attempting to get the object's state, and no other factories are
138 * to be tried.
139 *
140 * @see DirectoryManager#getStateToBind
141 */
142 public Result getStateToBind(Object obj, Name name, Context nameCtx,
143 Hashtable<?,?> environment,
144 Attributes inAttrs)
145 throws NamingException;
146
147
148 /**
149 * An object/attributes pair for returning the result of
150 * DirStateFactory.getStateToBind().
151 */
152 public static class Result {
153 /**
154 * The possibly null object to be bound.
155 */
156 private Object obj;
157
158
159 /**
160 * The possibly null attributes to be bound.
161 */
162 private Attributes attrs;
163
164 /**
165 * Constructs an instance of Result.
166 *
167 * @param obj The possibly null object to be bound.
168 * @param outAttrs The possibly null attributes to be bound.
169 */
170 public Result(Object obj, Attributes outAttrs) {
171 this.obj = obj;
172 this.attrs = outAttrs;
173 }
174
175 /**
176 * Retrieves the object to be bound.
177 * @return The possibly null object to be bound.
178 */
179 public Object getObject() { return obj; };
180
181 /**
182 * Retrieves the attributes to be bound.
183 * @return The possibly null attributes to be bound.
184 */
185 public Attributes getAttributes() { return attrs; };
186
187 }
188 }
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