jax-rs.whiteboard/src/main/java/org/apache/aries/jax/rs/whiteboard/internal/SingletonServiceTrackerCustomizer.java

/*
 * 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.
 */

package org.apache.aries.jax.rs.whiteboard.internal;

import org.apache.cxf.Bus;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
import org.osgi.util.tracker.ServiceTrackerCustomizer;

import javax.ws.rs.core.Application;
import java.util.Collections;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;
import java.util.Set;

public class SingletonServiceTrackerCustomizer
    implements ServiceTrackerCustomizer
        <Object, SingletonServiceTrackerCustomizer.Tracked> {

    private BundleContext _bundleContext;
    private Bus _bus;

    public SingletonServiceTrackerCustomizer(
        BundleContext bundleContext, Bus bus) {

        _bundleContext = bundleContext;
        _bus = bus;
    }

    @Override
    public Tracked addingService(
        ServiceReference<Object> serviceReference) {

        final Object service = _bundleContext.getService(
            serviceReference);

        try {
            String[] propertyKeys = serviceReference.getPropertyKeys();

            Map<String, Object> properties = new HashMap<>(
                propertyKeys.length);

            for (String propertyKey : propertyKeys) {
                if (propertyKey.equals("osgi.jaxrs.resource.base")) {
                    continue;
                }
                properties.put(
                    propertyKey, serviceReference.getProperty(propertyKey));
            }

            properties.put(
                "CXF_ENDPOINT_ADDRESS",
                serviceReference.getProperty("osgi.jaxrs.resource.base").
                    toString());

            CXFJaxRsServiceRegistrator cxfJaxRsServiceRegistrator =
                new CXFJaxRsServiceRegistrator(
                    _bus,
                    new Application() {
                        @Override
                        public Set<Object> getSingletons() {
                            return Collections.singleton(service);
                        }
                    },
                    properties);

            return new Tracked(
                cxfJaxRsServiceRegistrator, service,
                _bundleContext.registerService(
                    CXFJaxRsServiceRegistrator.class,
                    cxfJaxRsServiceRegistrator, new Hashtable<>(properties)));
        }
        catch (Exception e) {
            _bundleContext.ungetService(serviceReference);

            throw e;
        }
    }

    @Override
    public void modifiedService(
        ServiceReference<Object> serviceReference, Tracked tracked) {

        removedService(serviceReference, tracked);

        addingService(serviceReference);
    }

    @Override
    public void removedService(
        ServiceReference<Object> reference, Tracked tracked) {

        _bundleContext.ungetService(reference);

        Object service = tracked.getService();

        CXFJaxRsServiceRegistrator cxfJaxRsServiceRegistrator =
            tracked.getCxfJaxRsServiceRegistrator();

        cxfJaxRsServiceRegistrator.close();

        tracked.getCxfJaxRsServiceRegistratorServiceRegistration().unregister();
    }

    public static class Tracked {

        private final CXFJaxRsServiceRegistrator _cxfJaxRsServiceRegistrator;
        private final Object _service;
        private final ServiceRegistration<CXFJaxRsServiceRegistrator>
            _cxfJaxRsServiceRegistratorServiceRegistration;

        public Object getService() {
            return _service;
        }

        public CXFJaxRsServiceRegistrator getCxfJaxRsServiceRegistrator() {
            return _cxfJaxRsServiceRegistrator;
        }

        public ServiceRegistration<CXFJaxRsServiceRegistrator>
            getCxfJaxRsServiceRegistratorServiceRegistration() {

            return _cxfJaxRsServiceRegistratorServiceRegistration;
        }

        public Tracked(
            CXFJaxRsServiceRegistrator cxfJaxRsServiceRegistrator,
            Object service,
            ServiceRegistration<CXFJaxRsServiceRegistrator>
                cxfJaxRsServiceRegistratorServiceRegistration) {

            _cxfJaxRsServiceRegistrator = cxfJaxRsServiceRegistrator;
            _service = service;
            _cxfJaxRsServiceRegistratorServiceRegistration =
                cxfJaxRsServiceRegistratorServiceRegistration;
        }

    }

}