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<a class="nav-link" href="../apache-felix-maven-scr-plugin/apache-felix-scr-bndtools-use.html">Apache Felix SCR Annotations BndTools Use</a>
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<a class="nav-link" href="../apache-felix-maven-scr-plugin/apache-felix-scr-ant-task-use.html">Apache Felix SCR Ant Task Use</a>
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<a class="nav-link" href="../apache-felix-maven-scr-plugin/extending-scr-annotations.html">Extending SCR Annotations Excerpt: How add new Annotations extending the base Annotations</a>
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<a class="nav-link" href="../apache-felix-maven-scr-plugin/scr-annotations.html">SCR Annotations Excerpt: Using Java 5 Annotations to describe the component or service.</a>
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<a class="nav-link" href="../apache-felix-maven-scr-plugin/scr-javadoc-tags.html">SCR JavaDoc Tags Excerpt: Using JavaDoc Tags to describe the component or service.</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial.html">Apache Felix OSGi Tutorial</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-faq.html">OSGi Frequently Asked Questions</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-2.html">Apache Felix Tutorial Example 2</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-2b.html">Apache Felix Tutorial Example 2b</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-3.html">Apache Felix Tutorial Example 3</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-4.html">Apache Felix Tutorial Example 4</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-5.html">Apache Felix Tutorial Example 5</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-6.html">Example 6 - Spell Checker Service Bundle</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-7.html">Example 7 - Spell Checker Client Bundle</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-8.html">Example 8 - Spell Checker Service using Service Binder</a>
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<a class="nav-link" href="../../tutorials-examples-and-presentations/apache-felix-osgi-tutorial/apache-felix-tutorial-example-9.html">Example 9 - Spell Checker Service using Declarative Services</a>
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<h1 class="page">Apache Felix Framework Frequently Asked Questions</h1>
<div class="sect1">
<h2 id="_is_the_felix_framework_compliant_with_the_osgi_specification"><a class="anchor" href="#_is_the_felix_framework_compliant_with_the_osgi_specification"></a>Is the Felix framework compliant with the OSGi specification?</h2>
<div class="sectionbody">
<div class="paragraph">
<p>Yes.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_if_i_use_bundles_from_felix_will_my_application_be_tied_to_the_felix_framework"><a class="anchor" href="#_if_i_use_bundles_from_felix_will_my_application_be_tied_to_the_felix_framework"></a>If I use bundles from Felix, will my application be tied to the Felix framework?</h2>
<div class="sectionbody">
<div class="paragraph">
<p>See the answer in the <a href="../../tutorials-examples-and-presentations/apache-felix-osgi-faq.html#subproject-independence" class="page">OSGi FAQ</a>.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_when_i_update_my_bundle_why_are_my_bundles_old_classes_still_being_used"><a class="anchor" href="#_when_i_update_my_bundle_why_are_my_bundles_old_classes_still_being_used"></a>When I update my bundle, why are my bundle&#8217;s old classes still being used?</h2>
<div class="sectionbody">
<div class="paragraph">
<p>See the answer in the <a href="../../tutorials-examples-and-presentations/apache-felix-osgi-faq.html#bundle-update-visibility" class="page">OSGi FAQ</a>.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_why_do_i_get_an_unknown_protocol_http_exception_when_i_run_felix_on_a_non_sun_jre"><a class="anchor" href="#_why_do_i_get_an_unknown_protocol_http_exception_when_i_run_felix_on_a_non_sun_jre"></a>Why do I get an "Unknown protocol: http" exception when I run Felix on a non-Sun JRE?</h2>
<div class="sectionbody">
<div class="paragraph">
<p>Felix installs the URL Handlers service by default.
If you do not want this service you can disable it, by setting the <code>felix.service.urlhandlers</code> property to <code>false</code> in the <code>config.properties</code> file.
It is not recommended to disable this, but the main reason for doing so it because the URL Handlers implementation invokes methods to set the singleton factories for URL stream and content handler factories.
Assuming that you want to use URL Handlers service, you must configure it if you aren&#8217;t running on the standard Sun JRE.</p>
</div>
<div class="paragraph">
<p>The URL Handlers service extends the standard Java URL stream and content handler mechanism to work in an OSGi environment.
The way that built-in URL protocol and content handlers are discovered is by probing packages for the appropriate classes to handle the protocol/content.
For example, the default package for Sun protocol handlers is:</p>
</div>
<div class="literalblock">
<div class="content">
<pre>sun.net.www.protocol</pre>
</div>
</div>
<div class="paragraph">
<p>If someone tries to create a URL for the "http" protocol, then the class to handle the protocol will be:</p>
</div>
<div class="literalblock">
<div class="content">
<pre>sun.net.www.protocol.http.Handler</pre>
</div>
</div>
<div class="paragraph">
<p>A similar process is followed for content handlers, whose default package is:</p>
</div>
<div class="literalblock">
<div class="content">
<pre>sun.net.www.content</pre>
</div>
</div>
<div class="paragraph">
<p>If you are running on a VM that is different than Sun&#8217;s, then you must determine what are the default packages used for its protocol and content handlers.
Once you know this information, then you can configure Felix to use those packages instead of the default one.
You can configure Felix by setting the following system properties:</p>
</div>
<div class="literalblock">
<div class="content">
<pre>java.protocol.handler.pkgs</pre>
</div>
</div>
<div class="paragraph">
<p>and</p>
</div>
<div class="literalblock">
<div class="content">
<pre>java.content.handler.pkgs</pre>
</div>
</div>
<table class="tableblock frame-all grid-all stretch">
<colgroup>
<col style="width: 33.3333%;">
<col style="width: 33.3333%;">
<col style="width: 33.3334%;">
</colgroup>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">The value of these properties is a list of "</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">" delimited package names to be searched for protocol and content handlers, respectively.
See the Java documentation for <a href="http://java.sun.com/javase/6/docs/api/java/net/URL.html#URL(java.lang.String,%20java.lang.String,%20int,%20java.lang.String)">stream</a> and [content</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><a href="http://java.sun.com/javase/6/docs/api/java/net/URLConnection.html#getContent(" class="bare">http://java.sun.com/javase/6/docs/api/java/net/URLConnection.html#getContent(</a>)] handlers for more information.</p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
<p>There are two ways to set these system properties.
The first way is using the standard <code>-D&lt;property&gt;=&lt;value&gt;</code> syntax when executing <code>java</code> or if you are using Felix' standard <code>Main.java</code> launcher, you can put the system properties into the <code>conf/system.properties</code> file so that they get set automatically each time you execute Felix.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_what_is_the_daemon_status_of_framework_created_threads"><a class="anchor" href="#_what_is_the_daemon_status_of_framework_created_threads"></a>What is the daemon status of framework created threads?</h2>
<div class="sectionbody">
<div class="paragraph">
<p>The framework creates a few threads for handling specific tasks, such as event delivery or handling start level change requests.
All framework threads are explicitly started as daemon threads except the event dispatcher thread.
The logic behind this is that the event dispatcher thread should exit when it is done delivering events.
However, if an application is hosting an instance of the framework, it is possible to make the event dispatcher thread a daemon by starting your framework instance from a daemon thread, in which case the event dispatcher thread will inherit this setting.</p>
</div>
<div class="paragraph">
<p>For bundle developers, it is probably best to explicitly define any created threads as daemon or non-daemon to avoid any ambiguity.</p>
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