Java tutorial
/** * Licensed to the Austrian Association for Software Tool Integration (AASTI) * under one or more contributor license agreements. See the NOTICE file * distributed with this work for additional information regarding copyright * ownership. The AASTI 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.openengsb.core.test; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.ListIterator; import org.apache.commons.lang.ArrayUtils; import org.osgi.util.tracker.ServiceTracker; public final class ServiceList<ServiceType> implements List<ServiceType> { private ServiceTracker<ServiceType, ServiceType> tracker; public ServiceList(ServiceTracker<ServiceType, ServiceType> tracker) { this.tracker = tracker; tracker.open(); } @Override public int size() { return tracker.size(); } @Override public boolean isEmpty() { return tracker.size() == 0; } @Override public boolean contains(Object o) { return ArrayUtils.contains(tracker.getServices(), o); } @Override public Iterator<ServiceType> iterator() { return asList().iterator(); } @Override public Object[] toArray() { if (tracker.getServices() == null) { return new Object[0]; } return tracker.getServices(); } @Override public <T> T[] toArray(T[] a) { return asList().toArray(a); } @Override public boolean add(ServiceType e) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public boolean remove(Object o) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public boolean containsAll(Collection<?> c) { return asList().containsAll(c); } @Override public boolean addAll(Collection<? extends ServiceType> c) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public boolean addAll(int index, Collection<? extends ServiceType> c) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public boolean removeAll(Collection<?> c) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public boolean retainAll(Collection<?> c) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public void clear() { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @SuppressWarnings("unchecked") @Override public ServiceType get(int index) { return (ServiceType) tracker.getServices()[index]; } @Override public ServiceType set(int index, ServiceType element) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public void add(int index, ServiceType element) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public ServiceType remove(int index) { throw new UnsupportedOperationException("modifying the service-list is not allowed"); } @Override public int indexOf(Object o) { return ArrayUtils.indexOf(tracker.getServices(), o); } @Override public int lastIndexOf(Object o) { return ArrayUtils.lastIndexOf(tracker.getServices(), o); } @Override public ListIterator<ServiceType> listIterator() { return asList().listIterator(); } @Override public ListIterator<ServiceType> listIterator(int index) { return asList().listIterator(index); } @Override public List<ServiceType> subList(int fromIndex, int toIndex) { return asList().subList(fromIndex, toIndex); } private List<ServiceType> asList() { @SuppressWarnings("unchecked") ServiceType[] services = (ServiceType[]) tracker.getServices(); if (services == null) { return Collections.emptyList(); } return Arrays.asList(services); } }