juneau-doc/docs/Topics/06.juneau-rest-server/37.UsingWithOsgi.html

<!--
/***************************************************************************************************************************
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *  
 *  http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations under the License.
 ***************************************************************************************************************************/
 -->

Using with OSGi

<p>
	Since REST servlets are basically just <l>HttpServlets</l>, incorporating them into an OSGi environment
	is pretty straightforward.
</p>
<p>
	The following code shows how to register your REST servlets in an OSGi <l>Activator</l>:
</p>
<p class='bpcode w800'>
	<jk>package</jk> org.apache.juneau.examples.rest;
	
	<jk>import</jk> org.osgi.framework.*;
	<jk>import</jk> org.osgi.service.http.*;
	<jk>import</jk> org.osgi.util.tracker.*;
	
	<jk>import</jk> org.apache.juneau.rest.samples.*;
	
	<jd>/**
	 * Activator class used when running samples as a bundle in an OSGi environment.
	 */</jd>
	<jk>public class</jk> Activator <jk>implements</jk> BundleActivator, ServiceTrackerCustomizer {
	
		<jk>private</jk> ServiceTracker <jf>httpServiceTracker</jf>;
		<jk>private</jk> BundleContext <jf>context</jf>;
	
		<ja>@Override</ja> <jc>/* BundleActivator */</jc>
		<jk>public void</jk> start(BundleContext context) <jk>throws</jk> Exception {
			<jk>this</jk>.<jf>context</jf> = context;
			<jf>httpServiceTracker</jf> = <jk>new</jk> ServiceTracker(context, HttpService.<jk>class</jk>.getName(), <jk>this</jk>);
			<jf>httpServiceTracker</jf>.open();
		}
	
		<ja>@Override</ja> <jc>/* BundleActivator */</jc>
		<jk>public void</jk> stop(BundleContext context) <jk>throws</jk> Exception {
			<jf>httpServiceTracker</jf>.close();
		}
	
		<ja>@Override</ja> <jc>/* ServiceTrackerCustomizer */</jc>
		<jk>public</jk> Object addingService(ServiceReference reference) {
			Object service = <jf>context</jf>.getService(reference);
	
			<jk>if</jk> (service <jk>instanceof</jk> HttpService) {
				HttpService s = (HttpService)service;
				<jk>try</jk> {
					s.registerServlet(<js>"/sample"</js>, <jk>new</jk> MyRestServlet(), <jk>null</jk>, <jk>null</jk>);
				} <jk>catch</jk> (Exception e) {
					<jk>throw new</jk> RuntimeException(e);
				}
			}
	
			<jk>return</jk> service;
		}
	
		<ja>@Override</ja> <jc>/* ServiceTrackerCustomizer */</jc>
		<jk>public void</jk> modifiedService(ServiceReference reference, Object service) {
		}
	
		<ja>@Override</ja> <jc>/* ServiceTrackerCustomizer */</jc>
		<jk>public void</jk> removedService(ServiceReference reference, Object service) {
		}
	}
</p>