getting-started/src/web-module/osgi-service.xml

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<!DOCTYPE section PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
		"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<section id="osgi.service">
	<title>Publishing an OSGi Service</title>
	<para>
		At the end of the previous step, a dependency was created on an OSGi Service Registry exposed instance of
		<classname>greenpages.Directory</classname>. The application would not start because no other bundle was
		contributing an instance of this service to the Service Registry.
	</para>
<para>Stop the server instance before proceeding.</para>


	<section id="osgi.service.implementation">
		<title>Add Implementation</title>
		<para>
			In this step Spring&rsquo;s context scanning is added which will create an instance of the
			<classname>DirectoryImpl</classname> class.
		</para>

		<para>
			Open the <classname>greenpages.internal.DirectoryImpl</classname> class in the <literal>greenpages.app</literal>
			project. Add the <interfacename>@Component</interfacename> annotation to the class:
<programlisting language="java"><![CDATA[@Component("directory")
public class DirectoryImpl implements Directory {
…]]>
</programlisting>
			generating imports with Eclipse&rsquo;s help if necessary.
		</para>
		<para>
			Open the <filename>META-INF/spring/module-context.xml</filename> in the <literal>greenpages.app</literal>
			project.  Add component scanning to this file:
<programlisting language="xml"><![CDATA[<context:component-scan base-package="greenpages.internal"/>]]>
</programlisting>
		</para>
		<para>
			When complete, go to the next step.
		</para>
	</section>

	<section id="osgi.service.publish">
		<title>Publish OSGi Service</title>
		<para>
			In this step the <classname>DirectoryImpl</classname> instance is published to the OSGi Service
			Registry.
		</para>
		
		<para>
			Open the <filename>META-INF/spring/osgi-context.xml</filename> file. Add the
			<literal><![CDATA[<osgi:service/>]]></literal> tag to publish the <literal>directory</literal> bean with an
			interface of <interfacename>greenpages.Directory</interfacename>.
<programlisting language="xml"><![CDATA[<osgi:service ref="directory" interface="greenpages.Directory"/>]]>
</programlisting>
		</para>
	</section>

	<section id="osgi.server.working">
		<title>A Working Web Application</title>

		<para>
			Start (or restart) the @webserv@ instance from the <literal>Servers</literal> view. If the @greenpages@ PAR was not 
			removed before, it will be automatically deployed, otherwise deploy it as before. There should be no errors reported.
            When @greenpages@ is deployed successfully, open a web browser and navigate to
			<ulink url="http://localhost:8080/greenpages">http://localhost:8080/greenpages</ulink>. On
			the home page type <literal>wilkinson</literal> into the search field and press <emphasis>Submit</emphasis>.
			Unlike the previous attempt, this should return a list (of size 1) of search results. From here, select
			<emphasis>view</emphasis> to get the <quote>detailed</quote> listing.
		<mediaobject>
			<imageobject role="fo">
				<imagedata fileref="images/web-module/greenpages-listing-success.png" format="PNG" align="center" width="15cm"/>
			</imageobject>
			<imageobject role="html">
				<imagedata fileref="images/web-module/greenpages-listing-success.png" format="PNG" align="center"/>
			</imageobject>
		</mediaobject>
    	This uses a stub implementation of the <classname>Directory</classname> interface which only knows about <quote>Andy Wilkinson</quote>.
		</para>
		<para>
			The web interface is complete enough. Go to the next chapter to see the middle tier implementation.
		</para>
	</section>
</section>