001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.blueprint;
018    
019    import java.io.IOException;
020    import java.util.Map;
021    import java.util.Properties;
022    
023    import org.apache.camel.TypeConverter;
024    import org.apache.camel.core.osgi.OsgiCamelContextHelper;
025    import org.apache.camel.core.osgi.OsgiCamelContextPublisher;
026    import org.apache.camel.core.osgi.OsgiFactoryFinderResolver;
027    import org.apache.camel.core.osgi.OsgiTypeConverter;
028    import org.apache.camel.core.osgi.utils.BundleContextUtils;
029    import org.apache.camel.core.osgi.utils.BundleDelegatingClassLoader;
030    import org.apache.camel.impl.DefaultCamelContext;
031    import org.apache.camel.spi.EventNotifier;
032    import org.apache.camel.spi.FactoryFinder;
033    import org.apache.camel.spi.Registry;
034    import org.apache.camel.util.LoadPropertiesException;
035    import org.osgi.framework.BundleContext;
036    import org.osgi.framework.ServiceEvent;
037    import org.osgi.framework.ServiceListener;
038    import org.osgi.framework.ServiceRegistration;
039    import org.osgi.service.blueprint.container.BlueprintContainer;
040    import org.osgi.service.blueprint.container.BlueprintEvent;
041    import org.osgi.service.blueprint.container.BlueprintListener;
042    import org.slf4j.Logger;
043    import org.slf4j.LoggerFactory;
044    
045    /**
046     * OSGi Blueprint based {@link org.apache.camel.CamelContext}.
047     */
048    public class BlueprintCamelContext extends DefaultCamelContext implements ServiceListener, BlueprintListener {
049    
050        private static final Logger LOG = LoggerFactory.getLogger(BlueprintCamelContext.class);
051        
052        private BundleContext bundleContext;
053        private BlueprintContainer blueprintContainer;
054        private ServiceRegistration<?> registration;
055    
056        public BlueprintCamelContext() {
057        }
058    
059        public BlueprintCamelContext(BundleContext bundleContext, BlueprintContainer blueprintContainer) {
060            this.bundleContext = bundleContext;
061            this.blueprintContainer = blueprintContainer;
062    
063            // inject common osgi
064            OsgiCamelContextHelper.osgiUpdate(this, bundleContext);
065    
066            // and these are blueprint specific
067            setComponentResolver(new BlueprintComponentResolver(bundleContext));
068            setLanguageResolver(new BlueprintLanguageResolver(bundleContext));
069            setDataFormatResolver(new BlueprintDataFormatResolver(bundleContext));
070            setApplicationContextClassLoader(new BundleDelegatingClassLoader(bundleContext.getBundle()));
071        }
072    
073        public BundleContext getBundleContext() {
074            return bundleContext;
075        }
076    
077        public void setBundleContext(BundleContext bundleContext) {
078            this.bundleContext = bundleContext;
079        }
080    
081        public BlueprintContainer getBlueprintContainer() {
082            return blueprintContainer;
083        }
084    
085        public void setBlueprintContainer(BlueprintContainer blueprintContainer) {
086            this.blueprintContainer = blueprintContainer;
087        }
088       
089        public void init() throws Exception {
090            LOG.trace("init {}", this);
091    
092            // add service listener so we can be notified when blueprint container is done
093            // and we would be ready to start CamelContext
094            bundleContext.addServiceListener(this);
095            // add blueprint listener as service, as we need this for the blueprint container
096            // to support change events when it changes states
097            registration = bundleContext.registerService(BlueprintListener.class, this, null);
098        }
099    
100        public void destroy() throws Exception {
101            LOG.trace("destroy {}", this);
102    
103            // remove listener and stop this CamelContext
104            try {
105                bundleContext.removeServiceListener(this);
106            } catch (Exception e) {
107                LOG.warn("Error removing ServiceListener " + this + ". This exception is ignored.", e);
108            }
109            if (registration != null) {
110                try {
111                    registration.unregister();
112                } catch (Exception e) {
113                    LOG.warn("Error unregistering service registration " + registration + ". This exception is ignored.", e);
114                }
115                registration = null;
116            }
117    
118            // must stop Camel
119            stop();
120        }
121    
122        @Override
123        public Map<String, Properties> findComponents() throws LoadPropertiesException, IOException {
124            return BundleContextUtils.findComponents(bundleContext, this);
125        }
126    
127        @Override
128        public String getComponentDocumentation(String componentName) throws IOException {
129            return BundleContextUtils.getComponentDocumentation(bundleContext, this, componentName);
130        }
131    
132        @Override
133        public void blueprintEvent(BlueprintEvent event) {
134            // noop as we just needed to enlist the BlueprintListener to have events triggered to serviceChanged method
135        }
136    
137        @Override
138        public void serviceChanged(ServiceEvent event) {
139            if (LOG.isDebugEnabled()) {
140                LOG.debug("Service {} changed to {}", event, event.getType());
141            }
142            // look for blueprint container to be registered, and then we can start the CamelContext
143            if (event.getType() == ServiceEvent.REGISTERED
144                    && event.getServiceReference().isAssignableTo(bundleContext.getBundle(), "org.osgi.service.blueprint.container.BlueprintContainer")
145                    && bundleContext.getBundle().equals(event.getServiceReference().getBundle())) {
146                try {
147                    maybeStart();
148                } catch (Exception e) {
149                    LOG.error("Error occurred during starting Camel: " + this + " due " + e.getMessage(), e);
150                }
151            }
152        }
153    
154        @Override
155        protected TypeConverter createTypeConverter() {
156            // CAMEL-3614: make sure we use a bundle context which imports org.apache.camel.impl.converter package
157            BundleContext ctx = BundleContextUtils.getBundleContext(getClass());
158            if (ctx == null) {
159                ctx = bundleContext;
160            }
161            FactoryFinder finder = new OsgiFactoryFinderResolver(bundleContext).resolveDefaultFactoryFinder(getClassResolver());
162            return new OsgiTypeConverter(ctx, getInjector(), finder);
163        }
164    
165        @Override
166        protected Registry createRegistry() {
167            Registry reg = new BlueprintContainerRegistry(getBlueprintContainer());
168            return OsgiCamelContextHelper.wrapRegistry(this, reg, bundleContext);
169        }
170        
171        @Override
172        public void start() throws Exception {
173            final ClassLoader original = Thread.currentThread().getContextClassLoader();
174            try {
175                // let's set a more suitable TCCL while starting the context
176                Thread.currentThread().setContextClassLoader(getApplicationContextClassLoader());
177                super.start();
178            } finally {
179                Thread.currentThread().setContextClassLoader(original);
180            }
181        }
182    
183        private void maybeStart() throws Exception {
184            LOG.trace("maybeStart: {}", this);
185    
186            // allow to regsiter the BluerintCamelContext eager in the OSGi Service Registry, which ex is needed
187            // for unit testing with camel-test-blueprint
188            boolean eager = "true".equalsIgnoreCase(System.getProperty("registerBlueprintCamelContextEager"));
189            if (eager) {
190                for (EventNotifier notifer : getManagementStrategy().getEventNotifiers()) {
191                    if (notifer instanceof OsgiCamelContextPublisher) {
192                        OsgiCamelContextPublisher publisher = (OsgiCamelContextPublisher) notifer;
193                        publisher.registerCamelContext(this);
194                        break;
195                    }
196                }
197            }
198    
199            // for example from unit testing we want to start Camel later and not
200            // when blueprint loading the bundle
201            boolean skip = "true".equalsIgnoreCase(System.getProperty("skipStartingCamelContext"));
202            if (skip) {
203                LOG.trace("maybeStart: {} is skipping as System property skipStartingCamelContext is set", this);
204                return;
205            }
206    
207            if (!isStarted() && !isStarting()) {
208                LOG.debug("Starting {}", this);
209                start();
210            } else {
211                // ignore as Camel is already started
212                LOG.trace("Ignoring maybeStart() as {} is already started", this);
213            }
214        }
215    
216    }