1 /* 2 * Copyright [2006] [University Corporation for Advanced Internet Development, Inc.] 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.opensaml.saml2.metadata.provider; 18 19 import java.util.ArrayList; 20 import java.util.List; 21 22 /** 23 * An observable base implementation of metadata providers. An observer that clears the descriptor index kept by 24 * {@link AbstractMetadataProvider} is registered during construction time. 25 */ 26 public abstract class AbstractObservableMetadataProvider extends AbstractMetadataProvider implements 27 ObservableMetadataProvider { 28 29 /** List of registered observers. */ 30 private ArrayList<Observer> observers; 31 32 /** Constructor. */ 33 public AbstractObservableMetadataProvider() { 34 super(); 35 observers = new ArrayList<Observer>(); 36 observers.add(new DescriptorIndexClearingObserver()); 37 } 38 39 /** {@inheritDoc} */ 40 public List<Observer> getObservers() { 41 return observers; 42 } 43 44 /** 45 * Helper method for calling 46 * {@link org.opensaml.saml2.metadata.provider.ObservableMetadataProvider.Observer#onEvent(MetadataProvider)} on 47 * every registered Observer passing in this provider. 48 */ 49 protected void emitChangeEvent() { 50 synchronized (observers) { 51 for (Observer observer : observers) { 52 if (observer != null) { 53 observer.onEvent(this); 54 } 55 } 56 } 57 } 58 59 /** 60 * Observer that clears the descriptor index of this provider. 61 */ 62 private class DescriptorIndexClearingObserver implements Observer { 63 64 /** {@inheritDoc} */ 65 public void onEvent(MetadataProvider provider) { 66 ((AbstractMetadataProvider) provider).clearDescriptorIndex(); 67 } 68 } 69 }