| /* |
| * 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.dependencymanager; |
| |
| import java.util.Dictionary; |
| import java.util.List; |
| |
| import org.osgi.framework.ServiceRegistration; |
| |
| /** |
| * Service interface. |
| * |
| * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> |
| */ |
| public interface Service { |
| /** |
| * Adds a new dependency to this service. |
| * |
| * @param dependency the dependency to add |
| * @return this service |
| */ |
| public Service add(Dependency dependency); |
| |
| /** |
| * Removes a dependency from this service. |
| * |
| * @param dependency the dependency to remove |
| * @return this service |
| */ |
| public Service remove(Dependency dependency); |
| |
| /** |
| * Sets the public interface under which this service should be registered |
| * in the OSGi service registry. |
| * |
| * @param serviceName the name of the service interface |
| * @param properties the properties for this service |
| * @return this service |
| */ |
| public Service setInterface(String serviceName, Dictionary properties); |
| |
| /** |
| * Sets the public interfaces under which this service should be registered |
| * in the OSGi service registry. |
| * |
| * @param serviceNames the names of the service interface |
| * @param properties the properties for this service |
| * @return this service |
| */ |
| public Service setInterface(String[] serviceNames, Dictionary properties); |
| |
| /** |
| * Sets the implementation for this service. You can actually specify |
| * an instance you have instantiated manually, or a <code>Class</code> |
| * that will be instantiated using its default constructor when the |
| * required dependencies are resolved (effectively giving you a lazy |
| * instantiation mechanism). |
| * |
| * There are four special methods that are called when found through |
| * reflection to give you some life-cycle management options: |
| * <ol> |
| * <li><code>init()</code> is invoked right after the instance has been |
| * created, and before any dependencies are resolved, and can be used to |
| * initialize the internal state of the instance</li> |
| * <li><code>start()</code> is invoked after the required dependencies |
| * are resolved and injected, and before the service is registered</li> |
| * <li><code>stop()</code> is invoked right after the service is |
| * unregistered</li> |
| * <li><code>destroy()</code> is invoked after all dependencies are |
| * removed</li> |
| * </ol> |
| * In short, this allows you to initialize your instance before it is |
| * registered, perform some post-initialization and pre-destruction code |
| * as well as final cleanup. If a method is not defined, it simply is not |
| * called, so you can decide which one(s) you need. If you need even more |
| * fine-grained control, you can register as a service state listener too. |
| * |
| * @param implementation the implementation |
| * @return this service |
| * @see ServiceStateListener |
| */ |
| public Service setImplementation(Object implementation); |
| |
| /** |
| * Returns a list of dependencies. |
| * |
| * @return a list of dependencies |
| */ |
| public List getDependencies(); |
| |
| /** |
| * Returns the service registration for this service. The method |
| * will return <code>null</code> if no service registration is |
| * available. |
| * |
| * @return the service registration |
| */ |
| public ServiceRegistration getServiceRegistration(); |
| |
| /** |
| * Returns the service instance for this service. The method will |
| * return <code>null</code> if no service instance is available. |
| * |
| * @return the service instance |
| */ |
| public Object getService(); |
| |
| /** |
| * Returns the service properties associated with the service. |
| * |
| * @return the properties or <code>null</code> if there are none |
| */ |
| public Dictionary getServiceProperties(); |
| |
| /** |
| * Sets the service properties associated with the service. If the service |
| * was already registered, it will be updated. |
| * |
| * @param serviceProperties the properties |
| */ |
| public void setServiceProperties(Dictionary serviceProperties); |
| |
| /** |
| * Sets the names of the methods used as callbacks. These methods, when found, are |
| * invoked as part of the life-cycle management of the service implementation. The |
| * methods should not have any parameters. |
| * |
| * @param init the name of the init method |
| * @param start the name of the start method |
| * @param stop the name of the stop method |
| * @param destroy the name of the destroy method |
| * @return the service instance |
| */ |
| public Service setCallbacks(String init, String start, String stop, String destroy); |
| |
| // listener |
| /** |
| * Adds a service state listener to this service. |
| * |
| * @param listener the state listener |
| */ |
| public void addStateListener(ServiceStateListener listener); |
| |
| /** |
| * Removes a service state listener from this service. |
| * |
| * @param listener the state listener |
| */ |
| public void removeStateListener(ServiceStateListener listener); |
| |
| // events, must be fired when the dependency is started/active |
| |
| /** |
| * Will be called when the dependency becomes available. |
| * |
| * @param dependency the dependency |
| */ |
| public void dependencyAvailable(Dependency dependency); |
| |
| /** |
| * Will be called when the dependency changes. |
| * |
| * @param dependency the dependency |
| */ |
| public void dependencyUnavailable(Dependency dependency); |
| |
| /** |
| * Will be called when the dependency becomes unavailable. |
| * |
| * @param dependency the dependency |
| */ |
| public void dependencyChanged(Dependency dependency); |
| |
| /** |
| * Starts the service. This activates the dependency tracking mechanism |
| * for this service. |
| */ |
| public void start(); |
| |
| /** |
| * Stops the service. This deactivates the dependency tracking mechanism |
| * for this service. |
| */ |
| public void stop(); |
| |
| /** |
| * Sets the factory to use to create the implementation. You can specify |
| * both the factory class and method to invoke. The method should return |
| * the implementation, and can use any method to create it. Actually, this |
| * can be used together with <code>setComposition</code> to create a |
| * composition of instances that work together to implement a service. The |
| * factory itself can also be instantiated lazily by not specifying an |
| * instance, but a <code>Class</code>. |
| * |
| * @param factory the factory instance or class |
| * @param createMethod the name of the create method |
| */ |
| public Service setFactory(Object factory, String createMethod); |
| |
| /** |
| * Sets the factory to use to create the implementation. You specify the |
| * method to invoke. The method should return the implementation, and can |
| * use any method to create it. Actually, this can be used together with |
| * <code>setComposition</code> to create a composition of instances that |
| * work together to implement a service. |
| * <p> |
| * Note that currently, there is no default for the factory, so please use |
| * <code>setFactory(factory, createMethod)</code> instead. |
| * |
| * @param createMethod the name of the create method |
| */ |
| public Service setFactory(String createMethod); |
| |
| /** |
| * Sets the instance and method to invoke to get back all instances that |
| * are part of a composition and need dependencies injected. All of them |
| * will be searched for any of the dependencies. The method that is |
| * invoked must return an <code>Object[]</code>. |
| * |
| * @param instance the instance that has the method |
| * @param getMethod the method to invoke |
| */ |
| public Service setComposition(Object instance, String getMethod); |
| |
| /** |
| * Sets the method to invoke on the service implementation to get back all |
| * instances that are part of a composition and need dependencies injected. |
| * All of them will be searched for any of the dependencies. The method that |
| * is invoked must return an <code>Object[]</code>. |
| * |
| * @param getMethod the method to invoke |
| */ |
| public Service setComposition(String getMethod); |
| } |