| /* |
| * 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.felix.dm.impl.dependencies; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.util.ArrayList; |
| import java.util.Dictionary; |
| import java.util.List; |
| import java.util.Properties; |
| |
| import org.apache.felix.dm.dependencies.ResourceDependency; |
| import org.apache.felix.dm.impl.Logger; |
| import org.apache.felix.dm.resources.Resource; |
| import org.apache.felix.dm.resources.ResourceHandler; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.ServiceRegistration; |
| |
| public class ResourceDependencyImpl implements ResourceDependency, ResourceHandler, DependencyActivation { |
| private volatile BundleContext m_context; |
| private volatile ServiceRegistration m_registration; |
| // private long m_resourceCounter; |
| |
| private Object m_callbackInstance; |
| private String m_callbackAdded; |
| private String m_callbackChanged; |
| private String m_callbackRemoved; |
| private boolean m_autoConfig; |
| private final Logger m_logger; |
| private String m_autoConfigInstance; |
| protected List m_services = new ArrayList(); |
| private boolean m_isRequired; |
| private String m_resourceFilter; |
| private Resource m_trackedResource; |
| private boolean m_isStarted; |
| private List m_resources = new ArrayList(); |
| private Resource m_resourceInstance; |
| private boolean m_propagate; |
| private boolean m_isInstanceBound; |
| |
| public ResourceDependencyImpl(BundleContext context, Logger logger) { |
| m_context = context; |
| m_logger = logger; |
| m_autoConfig = true; |
| } |
| |
| public synchronized boolean isAvailable() { |
| return m_resources.size() > 0; |
| } |
| |
| public boolean isRequired() { |
| return m_isRequired; |
| } |
| |
| public boolean isInstanceBound() { |
| return m_isInstanceBound; |
| } |
| |
| public ResourceDependency setInstanceBound(boolean isInstanceBound) { |
| m_isInstanceBound = isInstanceBound; |
| return this; |
| } |
| |
| public void start(DependencyService service) { |
| boolean needsStarting = false; |
| synchronized (this) { |
| m_services.add(service); |
| if (!m_isStarted) { |
| m_isStarted = true; |
| needsStarting = true; |
| } |
| } |
| if (needsStarting) { |
| Properties props = null; |
| if (m_resourceFilter != null) { |
| props = new Properties(); |
| props.setProperty(Resource.FILTER, m_resourceFilter); |
| } |
| m_registration = m_context.registerService(ResourceHandler.class.getName(), this, props); |
| } |
| } |
| |
| public void stop(DependencyService service) { |
| boolean needsStopping = false; |
| synchronized (this) { |
| if (m_services.size() == 1 && m_services.contains(service)) { |
| m_isStarted = false; |
| needsStopping = true; |
| m_services.remove(service); |
| } |
| } |
| if (needsStopping) { |
| m_registration.unregister(); |
| m_registration = null; |
| } |
| } |
| |
| public void added(Resource resource) { |
| if (m_trackedResource == null || m_trackedResource.equals(resource)) { |
| long counter; |
| Object[] services; |
| synchronized (this) { |
| m_resources.add(resource); |
| counter = m_resources.size(); |
| services = m_services.toArray(); |
| } |
| for (int i = 0; i < services.length; i++) { |
| DependencyService ds = (DependencyService) services[i]; |
| if (counter == 1) { |
| ds.dependencyAvailable(this); |
| if (!isRequired()) { |
| invokeAdded(ds, resource); |
| } |
| } |
| else { |
| ds.dependencyChanged(this); |
| invokeAdded(ds, resource); |
| } |
| } |
| } |
| } |
| |
| public void changed(Resource resource) { |
| if (m_trackedResource == null || m_trackedResource.equals(resource)) { |
| Object[] services; |
| synchronized (this) { |
| services = m_services.toArray(); |
| } |
| for (int i = 0; i < services.length; i++) { |
| DependencyService ds = (DependencyService) services[i]; |
| invokeChanged(ds, resource); |
| } |
| } |
| } |
| |
| public void removed(Resource resource) { |
| if (m_trackedResource == null || m_trackedResource.equals(resource)) { |
| long counter; |
| Object[] services; |
| synchronized (this) { |
| m_resources.remove(resource); |
| counter = m_resources.size(); |
| services = m_services.toArray(); |
| } |
| for (int i = 0; i < services.length; i++) { |
| DependencyService ds = (DependencyService) services[i]; |
| if (counter == 0) { |
| ds.dependencyUnavailable(this); |
| if (!isRequired()) { |
| invokeRemoved(ds, resource); |
| } |
| } |
| else { |
| ds.dependencyChanged(this); |
| invokeRemoved(ds, resource); |
| } |
| } |
| } |
| } |
| |
| public void invokeAdded(DependencyService ds, Resource serviceInstance) { |
| Object[] callbackInstances = getCallbackInstances(ds); |
| if ((callbackInstances != null) && (m_callbackAdded != null)) { |
| invokeCallbackMethod(callbackInstances, m_callbackAdded, serviceInstance); |
| } |
| } |
| |
| public void invokeChanged(DependencyService ds, Resource serviceInstance) { |
| Object[] callbackInstances = getCallbackInstances(ds); |
| if ((callbackInstances != null) && (m_callbackChanged != null)) { |
| invokeCallbackMethod(callbackInstances, m_callbackChanged, serviceInstance); |
| } |
| } |
| |
| public void invokeRemoved(DependencyService ds, Resource serviceInstance) { |
| Object[] callbackInstances = getCallbackInstances(ds); |
| if ((callbackInstances != null) && (m_callbackRemoved != null)) { |
| invokeCallbackMethod(callbackInstances, m_callbackRemoved, serviceInstance); |
| } |
| } |
| |
| /** |
| * Sets the callbacks for this service. These callbacks can be used as hooks whenever a |
| * dependency is added or removed. When you specify callbacks, the auto configuration |
| * feature is automatically turned off, because we're assuming you don't need it in this |
| * case. |
| * |
| * @param added the method to call when a service was added |
| * @param removed the method to call when a service was removed |
| * @return this service dependency |
| */ |
| public synchronized ResourceDependency setCallbacks(String added, String removed) { |
| return setCallbacks(null, added, null, removed); |
| } |
| |
| /** |
| * Sets the callbacks for this service. These callbacks can be used as hooks whenever a |
| * dependency is added, changed or removed. When you specify callbacks, the auto |
| * configuration feature is automatically turned off, because we're assuming you don't |
| * need it in this case. |
| * |
| * @param added the method to call when a service was added |
| * @param changed the method to call when a service was changed |
| * @param removed the method to call when a service was removed |
| * @return this service dependency |
| */ |
| public synchronized ResourceDependency setCallbacks(String added, String changed, String removed) { |
| return setCallbacks(null, added, changed, removed); |
| } |
| |
| /** |
| * Sets the callbacks for this service. These callbacks can be used as hooks whenever a |
| * dependency is added or removed. They are called on the instance you provide. When you |
| * specify callbacks, the auto configuration feature is automatically turned off, because |
| * we're assuming you don't need it in this case. |
| * |
| * @param instance the instance to call the callbacks on |
| * @param added the method to call when a service was added |
| * @param removed the method to call when a service was removed |
| * @return this service dependency |
| */ |
| public synchronized ResourceDependency setCallbacks(Object instance, String added, String removed) { |
| return setCallbacks(instance, added, null, removed); |
| } |
| |
| /** |
| * Sets the callbacks for this service. These callbacks can be used as hooks whenever a |
| * dependency is added, changed or removed. They are called on the instance you provide. When you |
| * specify callbacks, the auto configuration feature is automatically turned off, because |
| * we're assuming you don't need it in this case. |
| * |
| * @param instance the instance to call the callbacks on |
| * @param added the method to call when a service was added |
| * @param changed the method to call when a service was changed |
| * @param removed the method to call when a service was removed |
| * @return this service dependency |
| */ |
| public synchronized ResourceDependency setCallbacks(Object instance, String added, String changed, String removed) { |
| ensureNotActive(); |
| // if at least one valid callback is specified, we turn off auto configuration |
| if (added != null || removed != null || changed != null) { |
| setAutoConfig(false); |
| } |
| m_callbackInstance = instance; |
| m_callbackAdded = added; |
| m_callbackChanged = changed; |
| m_callbackRemoved = removed; |
| return this; |
| } |
| |
| private void ensureNotActive() { |
| if (m_registration != null) { |
| throw new IllegalStateException("Cannot modify state while active."); |
| } |
| } |
| |
| /** |
| * Sets auto configuration for this service. Auto configuration allows the |
| * dependency to fill in any attributes in the service implementation that |
| * are of the same type as this dependency. Default is on. |
| * |
| * @param autoConfig the value of auto config |
| * @return this service dependency |
| */ |
| public synchronized ResourceDependency setAutoConfig(boolean autoConfig) { |
| ensureNotActive(); |
| m_autoConfig = autoConfig; |
| return this; |
| } |
| |
| /** |
| * Sets auto configuration for this service. Auto configuration allows the |
| * dependency to fill in the attribute in the service implementation that |
| * has the same type and instance name. |
| * |
| * @param instanceName the name of attribute to auto config |
| * @return this service dependency |
| */ |
| public synchronized ResourceDependency setAutoConfig(String instanceName) { |
| ensureNotActive(); |
| m_autoConfig = (instanceName != null); |
| m_autoConfigInstance = instanceName; |
| return this; |
| } |
| |
| private void invokeCallbackMethod(Object[] instances, String methodName, Object service) { |
| for (int i = 0; i < instances.length; i++) { |
| try { |
| invokeCallbackMethod(instances[i], methodName, service); |
| } |
| catch (NoSuchMethodException e) { |
| m_logger.log(Logger.LOG_DEBUG, "Method '" + methodName + "' does not exist on " + instances[i] + ". Callback skipped."); |
| } |
| } |
| } |
| |
| private void invokeCallbackMethod(Object instance, String methodName, Object service) throws NoSuchMethodException { |
| Class currentClazz = instance.getClass(); |
| boolean done = false; |
| while (!done && currentClazz != null) { |
| done = invokeMethod(instance, currentClazz, methodName, |
| new Class[][] {{Resource.class}, {Object.class}, {}}, |
| new Object[][] {{service}, {service}, {}}, |
| false); |
| if (!done) { |
| currentClazz = currentClazz.getSuperclass(); |
| } |
| } |
| if (!done && currentClazz == null) { |
| throw new NoSuchMethodException(methodName); |
| } |
| } |
| |
| private boolean invokeMethod(Object object, Class clazz, String name, Class[][] signatures, Object[][] parameters, boolean isSuper) { |
| Method m = null; |
| for (int i = 0; i < signatures.length; i++) { |
| Class[] signature = signatures[i]; |
| try { |
| m = clazz.getDeclaredMethod(name, signature); |
| if (!(isSuper && Modifier.isPrivate(m.getModifiers()))) { |
| m.setAccessible(true); |
| try { |
| m.invoke(object, parameters[i]); |
| } |
| catch (InvocationTargetException e) { |
| m_logger.log(Logger.LOG_ERROR, "Exception while invoking method " + m + ".", e); |
| } |
| // we did find and invoke the method, so we return true |
| return true; |
| } |
| } |
| catch (NoSuchMethodException e) { |
| // ignore this and keep looking |
| } |
| catch (Exception e) { |
| // could not even try to invoke the method |
| m_logger.log(Logger.LOG_ERROR, "Exception while trying to invoke method " + m + ".", e); |
| } |
| } |
| return false; |
| } |
| |
| private synchronized Object[] getCallbackInstances(DependencyService ds) { |
| if (m_callbackInstance == null) { |
| return ds.getCompositionInstances(); |
| } |
| else { |
| return new Object[] { m_callbackInstance }; |
| } |
| } |
| |
| public ResourceDependency setResource(Resource resource) { |
| m_trackedResource = resource; |
| return this; |
| } |
| |
| public synchronized ResourceDependency setRequired(boolean required) { |
| ensureNotActive(); |
| m_isRequired = required; |
| return this; |
| } |
| |
| public ResourceDependency setFilter(String resourceFilter) { |
| ensureNotActive(); |
| m_resourceFilter = resourceFilter; |
| return this; |
| } |
| public synchronized boolean isAutoConfig() { |
| return m_autoConfig; |
| } |
| |
| public Resource getResource() { |
| return lookupResource(); |
| } |
| |
| private Resource lookupResource() { |
| try { |
| return (Resource) m_resources.get(0); |
| } |
| catch (IndexOutOfBoundsException e) { |
| return null; |
| } |
| } |
| |
| public Object getAutoConfigInstance() { |
| return lookupResource(); |
| } |
| |
| public String getAutoConfigName() { |
| return m_autoConfigInstance; |
| } |
| |
| public Class getAutoConfigType() { |
| return Resource.class; |
| } |
| |
| public void invokeAdded(DependencyService service) { |
| // we remember these for future reference, needed for required callbacks |
| m_resourceInstance = lookupResource(); |
| invokeAdded(service, m_resourceInstance); |
| } |
| |
| public void invokeRemoved(DependencyService service) { |
| invokeRemoved(service, m_resourceInstance); |
| m_resourceInstance = null; |
| } |
| |
| public ResourceDependency setPropagate(boolean propagate) { |
| ensureNotActive(); |
| m_propagate = propagate; |
| return this; |
| } |
| |
| public Dictionary getProperties() { |
| Resource resource = lookupResource(); |
| if (resource != null) { |
| Properties props = new Properties(); |
| props.put(Resource.NAME, resource.getName()); |
| props.put(Resource.PATH, resource.getPath()); |
| props.put(Resource.REPOSITORY, resource.getRepository()); |
| return props; |
| } |
| else { |
| throw new IllegalStateException("cannot find resource"); |
| } |
| } |
| |
| public boolean isPropagated() { |
| return m_propagate; |
| } |
| } |