| author | igerasim |
| Tue, 09 Sep 2014 19:02:36 +0400 | |
| changeset 26458 | d6a5aed9204b |
| parent 25859 | 3317bb8137f4 |
| child 30678 | a8b7fd8ede97 |
| permissions | -rw-r--r-- |
| 2 | 1 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> |
2 |
<html> |
|
3 |
<head> |
|
4 |
<!-- |
|
| 5506 | 5 |
Copyright (c) 1999, 2006, Oracle and/or its affiliates. All rights reserved. |
| 2 | 6 |
DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
7 |
||
8 |
This code is free software; you can redistribute it and/or modify it |
|
9 |
under the terms of the GNU General Public License version 2 only, as |
|
| 5506 | 10 |
published by the Free Software Foundation. Oracle designates this |
| 2 | 11 |
particular file as subject to the "Classpath" exception as provided |
| 5506 | 12 |
by Oracle in the LICENSE file that accompanied this code. |
| 2 | 13 |
|
14 |
This code is distributed in the hope that it will be useful, but WITHOUT |
|
15 |
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
16 |
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
17 |
version 2 for more details (a copy is included in the LICENSE file that |
|
18 |
accompanied this code). |
|
19 |
||
20 |
You should have received a copy of the GNU General Public License version |
|
21 |
2 along with this work; if not, write to the Free Software Foundation, |
|
22 |
Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
|
23 |
||
|
5551
327690766109
6956202: Fix a few missed rebranding issues, please contact lines etc.
ohair
parents:
5506
diff
changeset
|
24 |
Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
327690766109
6956202: Fix a few missed rebranding issues, please contact lines etc.
ohair
parents:
5506
diff
changeset
|
25 |
or visit www.oracle.com if you need additional information or have any |
|
327690766109
6956202: Fix a few missed rebranding issues, please contact lines etc.
ohair
parents:
5506
diff
changeset
|
26 |
questions. |
| 2 | 27 |
--> |
28 |
</head> |
|
29 |
<body bgcolor="white"> |
|
30 |
||
31 |
Provides support for event notification when accessing naming and |
|
32 |
directory services. |
|
33 |
||
34 |
<p> |
|
35 |
This package defines the event notification operations of the Java Naming |
|
36 |
and Directory Interface<font size=-2><sup>TM</sup></font> (JNDI). |
|
37 |
JNDI provides naming and directory functionality to applications |
|
38 |
written in the Java programming language. It is designed to be |
|
39 |
independent of any specific naming or directory service |
|
40 |
implementation. Thus a variety of services--new, emerging, and |
|
41 |
already deployed ones--can be accessed in a common way. |
|
42 |
||
43 |
<h4>Naming Events</h4> |
|
44 |
<p> |
|
45 |
This package defines a <tt>NamingEvent</tt> class to represent an event |
|
46 |
that is generated by a naming/directory service. |
|
47 |
It also defines subinterfaces of <tt>Context</tt> and <tt>DirContext</tt>, |
|
48 |
called <tt>EventContext</tt> and <tt>EventDirContext</tt>, |
|
49 |
through which applications can register their interest in events |
|
50 |
fired by the context. |
|
51 |
<p> |
|
52 |
<tt>NamingEvent</tt> represents an event that occurs in a |
|
53 |
naming or directory service. There are two categories of naming events: |
|
54 |
<ul> |
|
55 |
<li>Those that affect the namespace (add/remove/rename an object) |
|
56 |
<li>Those that affect the objects' contents. |
|
57 |
</ul> |
|
58 |
Each category of events is handled by a corresponding listener: |
|
59 |
<tt>NamespaceChangeListener</tt>, <tt>ObjectChangeListener</tt>. |
|
60 |
<p> |
|
61 |
An application, for example, can register its interest in changes to |
|
62 |
objects in a context as follows: |
|
63 |
<blockquote> |
|
64 |
<pre> |
|
65 |
EventContext src = |
|
66 |
(EventContext)(new InitialContext()).lookup("o=wiz,c=us");
|
|
67 |
src.addNamingListener("ou=users", EventContext.ONELEVEL_SCOPE,
|
|
68 |
new ChangeHandler()); |
|
69 |
... |
|
70 |
class ChangeHandler implements ObjectChangeListener {
|
|
71 |
public void objectChanged(NamingEvent evt) {
|
|
72 |
System.out.println(evt.getNewBinding()); |
|
73 |
} |
|
74 |
public void namingExceptionThrown(NamingExceptionEvent evt) {
|
|
75 |
System.out.println(evt.getException()); |
|
76 |
} |
|
77 |
} |
|
78 |
</pre> |
|
79 |
</blockquote> |
|
80 |
||
81 |
<a name=THREADING></a> |
|
82 |
<h4>Threading Issues</h4> |
|
83 |
||
84 |
When an event is dispatched to a listener, the listener method (such |
|
85 |
as <tt>objectChanged()</tt>) may be executed in a thread other than the |
|
86 |
one in which the call to <tt>addNamingListener()</tt> was executed. |
|
87 |
The choice of which thread to use is made by the service provider. |
|
88 |
When an event is dispatched to multiple listeners, the service provider |
|
89 |
may choose (and is generally encouraged) to execute the listener methods |
|
90 |
concurrently in separate threads. |
|
91 |
<p> |
|
92 |
When a listener instance invokes <tt>NamingEvent.getEventContext()</tt>, |
|
93 |
it must take into account the possibility that other threads will be |
|
94 |
working with that context concurrently. Likewise, when a listener is |
|
95 |
registered via <tt>addNamingListener()</tt>, the registering thread |
|
96 |
must take into account the likely possibility that the service provider |
|
97 |
will later invoke the listeners in newly-created threads. As <tt>Context</tt> |
|
98 |
instances are not guaranteed to be thread-safe in general, all context |
|
99 |
operations must be synchronized as needed. |
|
100 |
||
101 |
<h4>Exception Handling</h4> |
|
102 |
||
103 |
When a listener registers for events with a context, the context might |
|
104 |
need to do some internal processing in order to collect information |
|
105 |
required to generate the events. The context, for example, might need |
|
106 |
to make a request to the server to register interest in changes |
|
107 |
on the server that will eventually be translated into events. |
|
108 |
If an exception occurs that prevents information about the events from |
|
109 |
being collected, the listener will never be notified of the events. |
|
110 |
When such an exception occurs, a <tt>NamingExceptionEvent</tt> is |
|
111 |
fired to notify the listener. The listener's |
|
112 |
<tt>namingExceptionThrown()</tt> method is invoked, as shown in the |
|
113 |
sample code above, |
|
114 |
and the listener is automatically deregistered. |
|
115 |
||
116 |
<h2>Package Specification</h2> |
|
117 |
||
118 |
||
119 |
The JNDI API Specification and related documents can be found in the |
|
120 |
<a href="../../../../technotes/guides/jndi/index.html">JNDI documentation</a>. |
|
121 |
||
122 |
@since 1.3 |
|
123 |
||
124 |
</body> |
|
125 |
</html> |