| /* |
| * 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 calculator.dosgi.impl; |
| |
| import static org.osgi.framework.Constants.OBJECTCLASS; |
| |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.Filter; |
| import org.osgi.framework.InvalidSyntaxException; |
| import org.osgi.util.tracker.ServiceTracker; |
| |
| import calculator.dosgi.CalculatorService; |
| import calculator.dosgi.operations.AddService; |
| import calculator.dosgi.operations.DivideService; |
| import calculator.dosgi.operations.MultiplyService; |
| import calculator.dosgi.operations.SubtractService; |
| |
| /** |
| * An implementation of the Calculator service. |
| */ |
| public class CalculatorServiceImpl implements CalculatorService { |
| private ServiceTracker remoteServices; |
| private ServiceTracker localServices; |
| |
| public CalculatorServiceImpl() { |
| super(); |
| } |
| |
| public CalculatorServiceImpl(BundleContext context) { |
| super(); |
| Filter remoteFilter = null, localFilter = null; |
| try { |
| remoteFilter = |
| context.createFilter("(&(" + OBJECTCLASS + "=calculator.dosgi.operations.*) (service.imported=*))"); |
| localFilter = |
| context.createFilter("(&(" + OBJECTCLASS + "=calculator.dosgi.operations.*) (!(service.imported=*)))"); |
| } catch (InvalidSyntaxException e) { |
| e.printStackTrace(); |
| } |
| this.remoteServices = new ServiceTracker(context, remoteFilter, null); |
| remoteServices.open(); |
| this.localServices = new ServiceTracker(context, localFilter, null); |
| localServices.open(); |
| } |
| |
| private <T> T getService(Class<T> cls) { |
| try { |
| // Wait for 10 seconds until the remote services are imported |
| remoteServices.waitForService(10000); |
| } catch (InterruptedException e) { |
| throw new IllegalStateException(cls.getSimpleName() + " is not available"); |
| } |
| Object[] remoteObjects = remoteServices.getServices(); |
| if (remoteObjects != null) { |
| for (Object s : remoteObjects) { |
| if (cls.isInstance(s)) { |
| System.out.println("Remote service: " + s); |
| return cls.cast(s); |
| } |
| } |
| } |
| Object[] localObjects = localServices.getServices(); |
| if (localObjects != null) { |
| for (Object s : localObjects) { |
| if (cls.isInstance(s)) { |
| System.out.println("Local service: " + s); |
| return cls.cast(s); |
| } |
| } |
| } |
| throw new IllegalStateException(cls.getSimpleName() + " is not available"); |
| } |
| |
| public double add(double n1, double n2) { |
| return getService(AddService.class).add(n1, n2); |
| } |
| |
| public double subtract(double n1, double n2) { |
| return getService(SubtractService.class).subtract(n1, n2); |
| } |
| |
| public double multiply(double n1, double n2) { |
| return getService(MultiplyService.class).multiply(n1, n2); |
| } |
| |
| public double divide(double n1, double n2) { |
| return getService(DivideService.class).divide(n1, n2); |
| } |
| } |