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 org.apache.camel.TypeConverter;
020    import org.apache.camel.core.osgi.OsgiCamelContextHelper;
021    import org.apache.camel.core.osgi.OsgiFactoryFinderResolver;
022    import org.apache.camel.core.osgi.OsgiTypeConverter;
023    import org.apache.camel.core.osgi.utils.BundleContextUtils;
024    import org.apache.camel.core.osgi.utils.BundleDelegatingClassLoader;
025    import org.apache.camel.impl.DefaultCamelContext;
026    import org.apache.camel.spi.FactoryFinder;
027    import org.apache.camel.spi.Registry;
028    import org.osgi.framework.BundleContext;
029    import org.osgi.framework.ServiceEvent;
030    import org.osgi.framework.ServiceListener;
031    import org.osgi.framework.ServiceRegistration;
032    import org.osgi.service.blueprint.container.BlueprintContainer;
033    import org.osgi.service.blueprint.container.BlueprintEvent;
034    import org.osgi.service.blueprint.container.BlueprintListener;
035    import org.slf4j.Logger;
036    import org.slf4j.LoggerFactory;
037    
038    public class BlueprintCamelContext extends DefaultCamelContext implements ServiceListener, BlueprintListener {
039    
040        private static final transient Logger LOG = LoggerFactory.getLogger(BlueprintCamelContext.class);
041    
042        private BundleContext bundleContext;
043        private BlueprintContainer blueprintContainer;
044        private ServiceRegistration<?> registration;
045    
046        public BlueprintCamelContext() {
047        }
048    
049        public BlueprintCamelContext(BundleContext bundleContext, BlueprintContainer blueprintContainer) {
050            this.bundleContext = bundleContext;
051            this.blueprintContainer = blueprintContainer;
052    
053            // inject common osgi
054            OsgiCamelContextHelper.osgiUpdate(this, bundleContext);
055    
056            // and these are blueprint specific
057            setComponentResolver(new BlueprintComponentResolver(bundleContext));
058            setLanguageResolver(new BlueprintLanguageResolver(bundleContext));
059            setDataFormatResolver(new BlueprintDataFormatResolver(bundleContext));
060            setApplicationContextClassLoader(new BundleDelegatingClassLoader(bundleContext.getBundle()));
061        }
062    
063        public BundleContext getBundleContext() {
064            return bundleContext;
065        }
066    
067        public void setBundleContext(BundleContext bundleContext) {
068            this.bundleContext = bundleContext;
069        }
070    
071        public BlueprintContainer getBlueprintContainer() {
072            return blueprintContainer;
073        }
074    
075        public void setBlueprintContainer(BlueprintContainer blueprintContainer) {
076            this.blueprintContainer = blueprintContainer;
077        }
078    
079        public void init() throws Exception {
080            LOG.trace("init {}", this);
081    
082            // add service listener so we can be notified when blueprint container is done
083            // and we would be ready to start CamelContext
084            bundleContext.addServiceListener(this);
085            // add blueprint listener as service, as we need this for the blueprint container
086            // to support change events when it changes states
087            registration = bundleContext.registerService(BlueprintListener.class, this, null);
088        }
089    
090        public void destroy() throws Exception {
091            LOG.trace("destroy {}", this);
092    
093            // remove listener and stop this CamelContext
094            try {
095                bundleContext.removeServiceListener(this);
096            } catch (Exception e) {
097                LOG.warn("Error removing ServiceListener " + this + ". This exception is ignored.", e);
098            }
099            if (registration != null) {
100                try {
101                    registration.unregister();
102                } catch (Exception e) {
103                    LOG.warn("Error unregistering service registration " + registration + ". This exception is ignored.", e);
104                }
105                registration = null;
106            }
107    
108            // must stop Camel
109            stop();
110        }
111    
112    
113        @Override
114        public void blueprintEvent(BlueprintEvent event) {
115            // noop as we just needed to enlist the BlueprintListener to have events triggered to serviceChanged method
116        }
117    
118        @Override
119        public void serviceChanged(ServiceEvent event) {
120            if (LOG.isDebugEnabled()) {
121                LOG.debug("Service {} changed to {}", event, event.getType());
122            }
123            // look for blueprint container to be registered, and then we can start the CamelContext
124            if (event.getType() == ServiceEvent.REGISTERED
125                    && event.getServiceReference().isAssignableTo(bundleContext.getBundle(), "org.osgi.service.blueprint.container.BlueprintContainer")
126                    && bundleContext.getBundle().equals(event.getServiceReference().getBundle())) {
127                try {
128                    maybeStart();
129                } catch (Exception e) {
130                    LOG.error("Error occurred during starting Camel: " + this + " due " + e.getMessage(), e);
131                }
132            }
133        }
134    
135        @Override
136        protected TypeConverter createTypeConverter() {
137            // CAMEL-3614: make sure we use a bundle context which imports org.apache.camel.impl.converter package
138            BundleContext ctx = BundleContextUtils.getBundleContext(getClass());
139            if (ctx == null) {
140                ctx = bundleContext;
141            }
142            FactoryFinder finder = new OsgiFactoryFinderResolver(bundleContext).resolveDefaultFactoryFinder(getClassResolver());
143            return new OsgiTypeConverter(ctx, getInjector(), finder);
144        }
145    
146        @Override
147        protected Registry createRegistry() {
148            Registry reg = new BlueprintContainerRegistry(getBlueprintContainer());
149            return OsgiCamelContextHelper.wrapRegistry(this, reg, bundleContext);
150        }
151    
152        private void maybeStart() throws Exception {
153            LOG.trace("maybeStart: {}", this);
154    
155            if (!isStarted() && !isStarting()) {
156                final ClassLoader original = Thread.currentThread().getContextClassLoader();
157                try {
158                    // let's set a more suitable TCCL while starting the context
159                    Thread.currentThread().setContextClassLoader(getApplicationContextClassLoader());
160                    LOG.debug("Starting {}", this);
161                    start();
162                } finally {
163                    Thread.currentThread().setContextClassLoader(original);
164                }
165            } else {
166                // ignore as Camel is already started
167                LOG.trace("Ignoring maybeStart() as {} is already started", this);
168            }
169        }
170    }