blob: b45345e927a13ffbff24f6959cca95b20da3829a [file] [log] [blame]
Clement Escoffier83507512008-10-13 07:33:03 +00001<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Clement Escoffier8251f602009-01-15 15:35:17 +00002<html><head>
3
4
Clement Escoffier83507512008-10-13 07:33:03 +00005
Clement Escoffier8251f602009-01-15 15:35:17 +00006 <title>Apache Felix - White Board Pattern Handler</title>
7 <link rel="stylesheet" href="white-board-pattern-handler_files/site.css" type="text/css" media="all">
8 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
9 </head><body>
10 <div class="title"><div class="logo"><a href="http://felix.apache.org/site/index.html"><img alt="Apache Felix" src="white-board-pattern-handler_files/logo.png" border="0"></a></div><div class="header"><a href="http://www.apache.org/"><img alt="Apache" src="white-board-pattern-handler_files/apache.png" border="0"></a></div></div>
11 <div class="menu">
12<ul>
13 <li><a href="http://felix.apache.org/site/news.html" title="news">news</a></li>
14 <li><a href="http://felix.apache.org/site/license.html" title="license">license</a></li>
Clement Escoffier373a57d2009-07-21 12:06:46 +000015 <li><a href="http://felix.apache.org/site/downloads.cgi" rel="nofollow">downloads</a></li>
Clement Escoffier8251f602009-01-15 15:35:17 +000016 <li><a href="http://felix.apache.org/site/documentation.html" title="documentation">documentation</a></li>
17 <li><a href="http://felix.apache.org/site/mailinglists.html" title="mailinglists">mailing lists</a></li>
18 <li><a href="http://felix.apache.org/site/contributing.html" title="Contributing">contributing</a></li>
Clement Escoffier373a57d2009-07-21 12:06:46 +000019 <li><a href="http://www.apache.org/" rel="nofollow">asf</a></li>
20 <li><a href="http://www.apache.org/foundation/sponsorship.html" rel="nofollow">sponsorship</a></li>
21 <li><a href="http://www.apache.org/foundation/thanks.html" rel="nofollow">sponsors</a>
Clement Escoffier83507512008-10-13 07:33:03 +000022<!-- ApacheCon Ad -->
Clement Escoffier373a57d2009-07-21 12:06:46 +000023<iframe src="white-board-pattern-handler_files/button.html" style="border-width: 0pt; float: left;" scrolling="no" frameborder="0" height="135" width="135"></iframe>
Clement Escoffier8251f602009-01-15 15:35:17 +000024<p style="height: 100px;">
25<!-- ApacheCon Ad -->
26</p></li></ul> </div>
27 <div class="main">
Clement Escoffier373a57d2009-07-21 12:06:46 +000028<style type="text/css">
29 @import url(http://people.apache.org/~clement/ipojo/site/superfish.css);
30</style>
31
32<style type="text/css">
33 @import url(http://people.apache.org/~clement/ipojo/site/style.css);
34</style>
35
36<p>
37<script class="javascript" src="white-board-pattern-handler_files/shCore.js"></script>
38<script class="javascript" src="white-board-pattern-handler_files/shBrushCSharp.js"></script>
39<script class="javascript" src="white-board-pattern-handler_files/shBrushPhp.js"></script>
40<script class="javascript" src="white-board-pattern-handler_files/shBrushJScript.js"></script>
41<script class="javascript" src="white-board-pattern-handler_files/shBrushVb.js"></script>
42<script class="javascript" src="white-board-pattern-handler_files/shBrushSql.js"></script>
43<script class="javascript" src="white-board-pattern-handler_files/shBrushXml.js"></script>
44<script class="javascript" src="white-board-pattern-handler_files/shBrushShell.js"></script>
45<script class="javascript" src="white-board-pattern-handler_files/shBrushDelphi.js"></script>
46<script class="javascript" src="white-board-pattern-handler_files/shBrushPython.js"></script>
47<script class="javascript" src="white-board-pattern-handler_files/shBrushJava.js"></script>
48
49<script type="text/javascript" src="white-board-pattern-handler_files/jquery-1.js"></script>
50<script type="text/javascript" src="white-board-pattern-handler_files/hoverIntent.js"></script>
51<script type="text/javascript" src="white-board-pattern-handler_files/superfish.js"></script>
52<script type="text/javascript" src="white-board-pattern-handler_files/supersubs.js"></script>
53
54<script type="text/javascript">
55
56 $(document).ready(function(){
57 $("ul.sf-menu").supersubs({
58 minWidth: 14, // minimum width of sub-menus in em units
59 maxWidth: 30, // maximum width of sub-menus in em units
60 extraWidth: 1 // extra width can ensure lines don't sometimes turn over
61 // due to slight rounding differences and font-family
62 }).superfish(); // call supersubs first, then superfish, so that subs are
63 // not display:none when measuring. Call before initialising
64 // containing tabs for same reason.
65 });
66
67</script>
68</p><div class="main">
69<div class="page-header">
70<img src="white-board-pattern-handler_files/header.png" class="header">
71<a href="http://ipojo.org/"><img src="white-board-pattern-handler_files/ipojo.png" class="header-logo" width="225"></a>
72<ul class="sf-menu sf-js-enabled sf-shadow" id="ipojo-menu">
73<li class="current">
74<!-- Menu Overview -->
75<a href="" class="sf-with-ul">Overview<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
76<ul style="float: none; width: 14em; display: none; visibility: hidden;">
77 <li style="white-space: normal; float: left; width: 100%;">
78 <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo.html" title="Apache Felix iPOJO">Home</a>
79 </li>
80 <li style="white-space: normal; float: left; width: 100%;">
81 <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-why-choose-ipojo.html" title="apache-felix-ipojo-why-choose-ipojo">Why choose iPOJO</a>
82 </li>
83 <li style="white-space: normal; float: left; width: 100%;">
84 <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-successstories.html" title="apache-felix-ipojo-successstories">Success stories</a>
85 </li>
86 <li style="white-space: normal; float: left; width: 100%;">
87 <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-feature-overview.html" title="Apache Felix iPOJO Feature Overview">Features</a>
88 </li>
89</ul>
90</li>
91
92<li class="">
93<!-- Menu download -->
94</li><li>
95<a href="http://felix.apache.org/site/download.html" title="Download">Download </a>
96</li>
97
98<li class="">
99<!-- Menu Documentation -->
100<a href="" class="sf-with-ul">Documentation<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
101<ul style="float: none; width: 14em; display: none; visibility: hidden;">
102 <!-- sub- menu : getting started -->
103 <li style="white-space: normal; float: left; width: 100%;" class="">
104 <a style="float: none; width: auto;" href="" class="sf-with-ul">Getting Started<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
105 <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;">
106 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-in-10-minutes.html" title="iPOJO in 10 minutes">iPOJO in 10 minutes</a></li>
107 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/how-to-use-ipojo-annotations.html" title="How to use iPOJO Annotations">Using Annotations</a></li>
108 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-hello-word-maven-based-tutorial.html" title="iPOJO Hello Word (Maven-Based) tutorial">Maven tutorial</a></li>
109 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-advanced-tutorial.html" title="iPOJO Advanced Tutorial">Advanced tutorial</a></li>
110 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-dosgi.html" title="apache-felix-ipojo-dosgi">Using Distributed OSGi</a></li>
111 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-composition-tutorial.html" title="iPOJO Composition Tutorial">Application Composition</a></li>
112 </ul>
113 </li> <!-- end of getting started -->
114 <!-- sub menu : Describing Components -->
115 <li style="white-space: normal; float: left; width: 100%;" class="">
116 <a style="float: none; width: auto;" href="http://felix.apache.org/site/describing-components.html" class="sf-with-ul">Describing components<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
117 <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;">
118 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/service-requirement-handler.html" title="Service Requirement Handler">Requiring a service</a></li>
119 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/providing-osgi-services.html" title="Providing OSGi services">Providing a service</a></li>
120 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/lifecycle-callback-handler.html" title="Lifecycle Callback Handler">Lifecycle management</a></li>
121 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/configuration-handler.html" title="Configuration Handler">Configuration</a></li>
122 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/architecture-handler.html" title="Architecture Handler">Introspection</a></li>
123 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/controller-lifecycle-handler.html" title="Controller Lifecycle Handler">Impacting the lifecycle</a></li>
124 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/event-admin-handlers.html" title="Event Admin Handlers">Asynchronous communication</a></li>
125 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-jmx-handler.html" title="iPOJO JMX Handler">JMX management</a></li>
126 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/extender-pattern-handler.html" title="Extender Pattern Handler">Extender pattern</a></li>
127 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="" title="White Board Pattern Handler">Whiteboard pattern</a></li>
128 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/temporal-service-dependency.html" title="Temporal Service Dependency">Temporal dependencies</a></li>
129 </ul>
130 </li> <!-- End of describing components -->
131 <!-- sub- menu : User Guide -->
132 <li style="white-space: normal; float: left; width: 100%;" class="">
133 <a style="float: none; width: auto;" href="" class="sf-with-ul">User Guide<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
134 <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;">
135 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/using-xml-schemas.html" title="Using XML Schemas">XML Schemas</a></li>
136 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-api.html" title="apache-felix-ipojo-api">API</a></li>
137 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-testing-components.html" title="apache-felix-ipojo-testing-components">Testing components</a></li>
138 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-eclipse-integration.html" title="apache-felix-ipojo-eclipse-integration">Eclipse Integration</a></li>
139 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-faq.html" title="iPOJO FAQ">FAQ</a></li>
140 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-reference-card.html" title="iPOJO-Reference-Card">Reference Card</a></li>
141 </ul>
142 </li> <!-- end of user guide -->
143 <!-- sub- menu : Dev Guide -->
144 <li class="" style="white-space: normal; float: left; width: 100%;">
145 <a style="float: none; width: auto;" href="" class="sf-with-ul">Advanced Topics<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
146 <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;">
147 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/ipojo/api/1.2.0" rel="nofollow">Javadoc</a></li>
148 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/how-to-write-your-own-handler.html" title="How to write your own handler">Handler guide</a></li>
149 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/how-to-use-ipojo-manipulation-metadata.html" title="How to use iPOJO Manipulation Metadata">Manipulation Metadata </a></li>
150 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/dive-into-the-ipojo-manipulation-depths.html" title="Dive into the iPOJO Manipulation depths">Dive into the iPOJO Manipulation depths</a></li>
151 </ul>
152 </li> <!-- End of Dev guide -->
153</ul>
154</li> <!-- End of doc -->
155<!-- Menu 4 : Tools -->
156<li class="">
157<a href="" class="sf-with-ul">Tools<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
158<ul style="float: none; width: 14em; display: none; visibility: hidden;">
159 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-ant-task.html" title="iPOJO Ant Task">Ant Task</a></li>
160 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-eclipse-plug-in.html" title="iPOJO Eclipse Plug-in">Eclipse Plugin</a></li>
161 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-maven-plug-in.html" title="iPOJO Maven Plug-in">Maven Plugin</a></li>
162 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-online-manipulator.html" title="apache-felix-ipojo-online-manipulator">Online Manipulator</a></li>
163 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-webconsole-plugin.html" title="iPOJO Webconsole Plugin">Webconsole plugin</a></li>
164 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-junit4osgi.html" title="apache-felix-ipojo-junit4osgi">Junit4OSGi</a></li>
165</ul>
166</li><!-- End of tools -->
167<!-- Menu 5 : Misc -->
168<li class="">
169<a href="" class="sf-with-ul">Misc<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a>
170<ul style="float: none; width: 14em; display: none; visibility: hidden;">
171 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-issuestracker.html" title="apache-felix-ipojo-issuestracker">Issues Tracker</a></li>
172 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-supportedvms.html" title="apache-felix-ipojo-supportedVMs">Supported JVMs</a></li>
173 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-supportedosgi.html" title="apache-felix-ipojo-supportedOSGi">Supported OSGi Implementations</a></li>
174 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://ipojo-dark-side.blogspot.com/" rel="nofollow">iPOJO's Dark Side Blog</a></li>
175 <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/article-presentations.html" title="Article &amp; Presentations">Article &amp; Presentations</a></li>
176</ul>
177</li><!-- End of misc -->
178</ul> <!-- End of the menu -->
179</div> <!-- Page header -->
180
181
182<div class="content">
183
Clement Escoffier8251f602009-01-15 15:35:17 +0000184<h1><a name="WhiteBoardPatternHandler-Thewhiteboardpatternhandler"></a>The white board pattern handler</h1>
185<p>The objective of this handler is to simplify the development of
186white-board architecture. This architecture-style is based is very
187close to the extender architecture style but use services instead of
Clement Escoffier373a57d2009-07-21 12:06:46 +0000188bundles.</p>
189
190<div class="toc">
191<ul>
192 <li><a href="#WhiteBoardPatternHandler-Thewhiteboardpattern">The whiteboard pattern</a></li>
193 <li><a href="#WhiteBoardPatternHandler-Usingthehandler">Using the handler</a></li>
194 <li><a href="#WhiteBoardPatternHandler-Configuration">Configuration</a></li>
195 <li><a href="#WhiteBoardPatternHandler-Configuringthehandlerwithannotations">Configuring the handler with annotations</a></li>
196 <li><a href="#WhiteBoardPatternHandler-Download">Download</a></li>
197</ul></div>
198
199<div class="panelMacro"><table class="infoMacro"><colgroup><col width="24"><col></colgroup><tbody><tr><td valign="top"><img src="white-board-pattern-handler_files/information.gif" alt="" border="0" align="absmiddle" height="16" width="16"></td><td><b>Change in the 1.2.0</b><br><p>The 1.2.0 uses the namespace <tt>org.apache.felix.ipojo.whiteboard</tt> instead of <tt>org.apache.felix.ipojo.white-board-pattern</tt></p></td></tr></tbody></table></div>
200
201<h2><a name="WhiteBoardPatternHandler-Thewhiteboardpattern"></a>The whiteboard pattern</h2>
202<p>A whiteboard is based on two different roles:</p>
Clement Escoffier8251f602009-01-15 15:35:17 +0000203<ul>
204 <li>A consumer looking to special services or a services published with a special mark</li>
205 <li>Looked services</li>
206</ul>
Clement Escoffier83507512008-10-13 07:33:03 +0000207
208
Clement Escoffier373a57d2009-07-21 12:06:46 +0000209<p>More information on this pattern is available in this <a href="http://www.osgi.org/wiki/uploads/Links/whiteboard.pdf" rel="nofollow">document</a><br>
Clement Escoffier8251f602009-01-15 15:35:17 +0000210Implementing a white board pattern could be complex as the extender
211needs to track these services dynamically. Indeed looked services can
212be highly dynamic; they can arrive, leave or be modified at runtime.<br>
213Several services specified in the OSGi specification use white board pattern such as the Device Access Manager.</p>
214
Clement Escoffier8251f602009-01-15 15:35:17 +0000215<h2><a name="WhiteBoardPatternHandler-Usingthehandler"></a>Using the handler</h2>
216<p>First of all, you need to configure the component type to use the handler such as:</p>
Clement Escoffier373a57d2009-07-21 12:06:46 +0000217<div class="code">
218<div class="dp-highlighter"><table class="dp-xml" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="line1"><span></span><span class="tag">&lt;</span><span>ipojo&nbsp;xmlns:</span><span class="attribute">wbp</span><span>=</span><span class="attribute-value">"org.apache.felix.ipojo.whiteboard"</span><span>&gt;&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span>component&nbsp;&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">className</span><span>=</span><span class="attribute-value">"org.apache.felix.ipojo.test.FooWhiteBoardPattern"</span><span>&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&gt;</span><span>&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span>wbp:wbp&nbsp;&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">filter</span><span>=</span><span class="attribute-value">"(my.property=1)"</span><span>&nbsp;&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">onArrival</span><span>=</span><span class="attribute-value">"onArrival"</span><span>&nbsp;&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">onDeparture</span><span>=</span><span class="attribute-value">"onDeparture"</span><span>&nbsp;&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="attribute">onModification</span><span>=</span><span class="attribute-value">"onModification"</span><span>&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">/&gt;</span><span>&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;</span><span>provides</span><span class="tag">/&gt;</span><span>&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="tag">&lt;/</span><span>component</span><span class="tag">&gt;</span><span>&nbsp;</span></td></tr></tbody></table></div><textarea style="display: none;" name="newcodemacro" class="xml:nocontrols:nogutter" rows="10" readonly="readonly">&lt;ipojo xmlns:wbp="org.apache.felix.ipojo.whiteboard"&gt;
Clement Escoffier83507512008-10-13 07:33:03 +0000219 &lt;component
Clement Escoffier373a57d2009-07-21 12:06:46 +0000220 className="org.apache.felix.ipojo.test.FooWhiteBoardPattern"
Clement Escoffier83507512008-10-13 07:33:03 +0000221 &gt;
222 &lt;wbp:wbp
Clement Escoffier373a57d2009-07-21 12:06:46 +0000223 filter="(my.property=1)"
224 onArrival="onArrival"
225 onDeparture="onDeparture"
226 onModification="onModification"
Clement Escoffier83507512008-10-13 07:33:03 +0000227 /&gt;
228
Clement Escoffier373a57d2009-07-21 12:06:46 +0000229 &lt;provides/&gt;
230 &lt;/component&gt;</textarea>
231<script class="javascript">
232 if(!window.newcodemacro_initialised)
233 {
234 window.newcodemacro_initialised = true;
235 window.oldonloadmethod = window.onload;
236 window.onload = function(){
237 dp.SyntaxHighlighter.HighlightAll('newcodemacro');
238 if(window.oldonloadmethod)
239 {
240 window.oldonloadmethod();
241 }
242 }
243 }
244
245</script>
246</div>
247
Clement Escoffier8251f602009-01-15 15:35:17 +0000248<p>Notice that, this handler is an external handler. So, it uses the "org.apache.felix.ipojo.whiteboard" namespace.<br>
249Once described, you can implement your component. The methods specified
250methods will be called when a matching services arrives or leaves or
251are modified. The modification callback is optional. A matching service
252is detected by confronting the service reference against the specified
253filter.<br>
254The filter can target specific service interface (with the objectclass property) or property values.<br>
255In the previous example, these methods could be: </p>
Clement Escoffier373a57d2009-07-21 12:06:46 +0000256<div class="code">
257<div class="dp-highlighter"><table class="dp-c" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="line1"><span></span><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;FooWhiteBoardPattern&nbsp;</span><span class="keyword">implements</span><span>&nbsp;Observable&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;List&nbsp;list&nbsp;=&nbsp;new&nbsp;ArrayList();&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;modifications&nbsp;=&nbsp;0;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">synchronized</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onArrival(ServiceReference&nbsp;ref)&nbsp;{&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;list.add(ref);&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">synchronized</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onDeparture(ServiceReference&nbsp;ref)&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;list.remove(ref);&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">synchronized</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onModification(ServiceReference&nbsp;ref)&nbsp;{&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;modifications&nbsp;=&nbsp;modifications&nbsp;+&nbsp;1;&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">synchronized</span><span>&nbsp;Map&nbsp;getObservations()&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Map&nbsp;map&nbsp;=&nbsp;new&nbsp;HashMap();&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;map.put(<span class="string">"list"</span><span>,&nbsp;list);&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;map.put(<span class="string">"modifications"</span><span>,&nbsp;new&nbsp;Integer(modifications));&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">return</span><span>&nbsp;map;&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;</td></tr></tbody></table></div><textarea style="display: none;" name="newcodemacro" class="java:nocontrols:nogutter" rows="10" readonly="readonly">public class FooWhiteBoardPattern implements Observable {
258 List list = new ArrayList();
259 int modifications = 0;
260 public synchronized void onArrival(ServiceReference ref) {
Clement Escoffier83507512008-10-13 07:33:03 +0000261 list.add(ref);
262 }
Clement Escoffier373a57d2009-07-21 12:06:46 +0000263 public synchronized void onDeparture(ServiceReference ref) {
Clement Escoffier83507512008-10-13 07:33:03 +0000264 list.remove(ref);
265 }
Clement Escoffier373a57d2009-07-21 12:06:46 +0000266 public synchronized void onModification(ServiceReference ref) {
Clement Escoffier83507512008-10-13 07:33:03 +0000267 modifications = modifications + 1;
268 }
Clement Escoffier373a57d2009-07-21 12:06:46 +0000269 public synchronized Map getObservations() {
270 Map map = new HashMap();
271 map.put("list", list);
272 map.put("modifications", new Integer(modifications));
273 return map;
274 }</textarea>
275<script class="javascript">
276 if(!window.newcodemacro_initialised)
277 {
278 window.newcodemacro_initialised = true;
279 window.oldonloadmethod = window.onload;
280 window.onload = function(){
281 dp.SyntaxHighlighter.HighlightAll('newcodemacro');
282 if(window.oldonloadmethod)
283 {
284 window.oldonloadmethod();
285 }
286 }
287 }
288
289</script>
290</div>
291
Clement Escoffier8251f602009-01-15 15:35:17 +0000292<p>All method received the arriving, leaving or modified service reference.</p>
293<h2><a name="WhiteBoardPatternHandler-Configuration"></a>Configuration</h2>
294<p>The handler has only three mandatory attributes:</p>
295<ul>
296 <li>Filter: filter use to discover matching filter.</li>
297 <li>onArrival: declaring the method to invoke when a matching service arrives</li>
298 <li>onDeparture: declaring the method to invoke when a matching service leaves</li>
299</ul>
Clement Escoffier83507512008-10-13 07:33:03 +0000300
301
Clement Escoffier8251f602009-01-15 15:35:17 +0000302<p>The onModification attribute is optional. This method is called when
303an injected service reference is modified but stills valid against the
304filter.</p>
Clement Escoffier373a57d2009-07-21 12:06:46 +0000305<div class="panelMacro"><table class="noteMacro"><colgroup><col width="24"><col></colgroup><tbody><tr><td valign="top"><img src="white-board-pattern-handler_files/warning.gif" alt="" border="0" align="absmiddle" height="16" width="16"></td><td><b>Notifications</b><br><p>The
306implementation will be notified of arrivals, modifications and
Clement Escoffier8251f602009-01-15 15:35:17 +0000307departures, despite the instance is invalid. Indeed, the implementation
Clement Escoffier373a57d2009-07-21 12:06:46 +0000308must release all objects created from another bundle as soon it leaves.</p></td></tr></tbody></table></div>
309<h2><a name="WhiteBoardPatternHandler-Configuringthehandlerwithannotations"></a>Configuring the handler with annotations</h2>
Clement Escoffier8251f602009-01-15 15:35:17 +0000310
311<p>It is possible to configure the handler with a simple annotation
312available in the annotation pack ('annotation' project in the iPOJO
313trunk). Here is an example of usage:</p>
Clement Escoffier373a57d2009-07-21 12:06:46 +0000314<div class="code">
315<div class="dp-highlighter"><table class="dp-c" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="line1"><span></span><span class="keyword">import</span><span>&nbsp;org.apache.felix.ipojo.annotations.Component;&nbsp;</span></td></tr><tr><td class="line2"><span class="keyword">import</span><span>&nbsp;org.osgi.framework.ServiceReference;&nbsp;</span></td></tr><tr><td class="line1"><span class="preprocessor"></span></td></tr><tr><td class="line2"><span class="preprocessor">@Component</span><span>&nbsp;</span></td></tr><tr><td class="line1"><span class="preprocessor">@org.apache.felix.ipojo.whiteboard.Wbp(filter="(foo=true)",&nbsp;</span><span>&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;onArrival=<span class="string">"onArrival"</span><span>,&nbsp;&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;onDeparture=<span class="string">"onDeparture"</span><span>,&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;onModification=<span class="string">"onModification"</span><span>)&nbsp;</span></td></tr><tr><td class="line1"><span class="keyword">public</span><span>&nbsp;</span><span class="keyword">class</span><span>&nbsp;WhiteBoardExemple&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onArrival(ServiceReference&nbsp;ref)&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;do&nbsp;something</span><span>&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onDeparture(ServiceReference&nbsp;ref)&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;do&nbsp;something</span><span>&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;</td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">public</span><span>&nbsp;</span><span class="keyword">void</span><span>&nbsp;onModification(ServiceReference&nbsp;ref)&nbsp;{&nbsp;</span></td></tr><tr><td class="line2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="comment">//&nbsp;do&nbsp;something</span><span>&nbsp;</span></td></tr><tr><td class="line1">&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;</td></tr><tr><td class="line2">&nbsp;</td></tr><tr><td class="line1">}&nbsp;</td></tr></tbody></table></div><textarea style="display: none;" name="newcodemacro" class="java:nocontrols:nogutter" rows="10" readonly="readonly">import org.apache.felix.ipojo.annotations.Component;
316import org.osgi.framework.ServiceReference;
Clement Escoffier8251f602009-01-15 15:35:17 +0000317
318@Component
Clement Escoffier373a57d2009-07-21 12:06:46 +0000319@org.apache.felix.ipojo.whiteboard.Wbp(filter="(foo=true)",
320 onArrival="onArrival",
321 onDeparture="onDeparture",
322 onModification="onModification")
323public class WhiteBoardExemple {
Clement Escoffier8251f602009-01-15 15:35:17 +0000324
Clement Escoffier373a57d2009-07-21 12:06:46 +0000325 public void onArrival(ServiceReference ref) {
326 // do something
327 }
Clement Escoffier8251f602009-01-15 15:35:17 +0000328
Clement Escoffier373a57d2009-07-21 12:06:46 +0000329 public void onDeparture(ServiceReference ref) {
330 // do something
331 }
Clement Escoffier8251f602009-01-15 15:35:17 +0000332
Clement Escoffier373a57d2009-07-21 12:06:46 +0000333 public void onModification(ServiceReference ref) {
334 // do something
335 }
Clement Escoffier8251f602009-01-15 15:35:17 +0000336
Clement Escoffier373a57d2009-07-21 12:06:46 +0000337}</textarea>
338<script class="javascript">
339 if(!window.newcodemacro_initialised)
340 {
341 window.newcodemacro_initialised = true;
342 window.oldonloadmethod = window.onload;
343 window.onload = function(){
344 dp.SyntaxHighlighter.HighlightAll('newcodemacro');
345 if(window.oldonloadmethod)
346 {
347 window.oldonloadmethod();
348 }
349 }
350 }
351
352</script>
353</div>
354
Clement Escoffier8251f602009-01-15 15:35:17 +0000355
356<p>The <tt>onModification</tt> attribute is optional.The <tt>filter</tt> attribute allows setting the service filter.</p>
Clement Escoffier83507512008-10-13 07:33:03 +0000357
Clement Escoffier8251f602009-01-15 15:35:17 +0000358<h2><a name="WhiteBoardPatternHandler-Download"></a>Download</h2>
359<p>The handler is available on the <a href="http://felix.apache.org/site/download.html" title="Download">download</a> page.<br>
Clement Escoffier373a57d2009-07-21 12:06:46 +0000360Sources are available on the Felix trunk at the following location: <a href="http://svn.apache.org/repos/asf/felix/trunk/ipojo/handler/whiteboard" rel="nofollow">http://svn.apache.org/repos/asf/felix/trunk/ipojo/handler/whiteboard</a>.
361<br clear="all">
362<br clear="all"></p>
Clement Escoffier83507512008-10-13 07:33:03 +0000363
Clement Escoffier373a57d2009-07-21 12:06:46 +0000364 </div>
365 <img src="white-board-pattern-handler_files/footer.png" class="footer">
366</div>
Clement Escoffier8251f602009-01-15 15:35:17 +0000367
368<script type="text/javascript">
369var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
370document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
371</script><script src="white-board-pattern-handler_files/ga.js" type="text/javascript"></script>
372<script type="text/javascript">
Clement Escoffier373a57d2009-07-21 12:06:46 +0000373try{
Clement Escoffier8251f602009-01-15 15:35:17 +0000374var pageTracker = _gat._getTracker("UA-1518442-4");
375pageTracker._trackPageview();
Clement Escoffier373a57d2009-07-21 12:06:46 +0000376} catch(err) {}
Clement Escoffier8251f602009-01-15 15:35:17 +0000377</script>
Clement Escoffier373a57d2009-07-21 12:06:46 +0000378
Clement Escoffier8251f602009-01-15 15:35:17 +0000379 </div>
380 </body></html>