| /* |
| * 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.lambda.samples.hello; |
| |
| import org.osgi.service.log.LogService; |
| |
| /** |
| * The implementation for our service provider. |
| * |
| * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> |
| */ |
| public class ServiceProviderImpl implements ServiceProvider { |
| /** |
| * Our log service, injected from Activator. |
| * If field is only accessed by callbacks, then you do not need to declare it as volatile, because the DM thread model |
| * ensures "safe publications" of objects when lifecycle or dependency callbacks are invoked. |
| * Here we declare the field using volatile because our hello method may be invoked from any thread, and declaring the field |
| * as volatile will ensure safe publication if the log service is replaced at runtime. |
| */ |
| volatile LogService log; |
| |
| void start() { |
| // Default lifecycle start calback (all required dependencies have been injected when start is called, |
| // and all optional dependency callbacks will be invoked after the start method. This allows to easily |
| // implement the whiteboard pattern: you are first injected with required dependencies, then you can initialize |
| // your component from the start callback, and then optional dependency callbacks are invoked. |
| |
| // Notice that all callbacks are serially executed and you don't need to synchronize your callbacks and |
| // you can perform any manual service registrations (using BundleContext.registerService) whithout dealing |
| // with synchronization, because no locks are held by DM when callbacks are invoked. |
| } |
| |
| @Override |
| public void hello() { |
| log.log(LogService.LOG_INFO, "ServiceProviderImpl.hello"); |
| } |
| } |