001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.hivemind.lib.impl;
016    
017    import java.util.ArrayList;
018    import java.util.List;
019    
020    import org.apache.hivemind.ApplicationRuntimeException;
021    import org.apache.hivemind.lib.RemoteExceptionCoordinator;
022    import org.apache.hivemind.lib.RemoteExceptionEvent;
023    import org.apache.hivemind.lib.RemoteExceptionListener;
024    
025    /**
026     * Core implementation of {@link org.apache.hivemind.lib.RemoteExceptionCoordinator}.
027     *
028     * @author Howard Lewis Ship
029     */
030    
031    public class RemoteExceptionCoordinatorImpl implements RemoteExceptionCoordinator
032    {
033        private boolean _locked;
034        private List _listeners;
035    
036        private void checkLocked(String methodName)
037        {
038            if (_locked)
039                throw new ApplicationRuntimeException(ImplMessages.coordinatorLocked(methodName));
040        }
041    
042        public synchronized void addRemoteExceptionListener(RemoteExceptionListener listener)
043        {
044            checkLocked("addRemoteExceptionListener");
045    
046            if (_listeners == null)
047                _listeners = new ArrayList();
048    
049            _listeners.add(listener);
050        }
051    
052        public synchronized void removeRemoteExceptionListener(RemoteExceptionListener listener)
053        {
054            checkLocked("removeRemoteExceptionListener");
055    
056            if (_listeners == null)
057                return;
058    
059            _listeners.remove(listener);
060        }
061    
062        public synchronized void fireRemoteExceptionDidOccur(Object source, Throwable exception)
063        {
064            checkLocked("sendNotification");
065    
066            if (_listeners == null || _listeners.size() == 0)
067                return;
068    
069            RemoteExceptionEvent event = new RemoteExceptionEvent(source, exception);
070    
071            int count = _listeners.size();
072    
073            _locked = true;
074    
075            try
076            {
077    
078                for (int i = 0; i < count; i++)
079                {
080                    RemoteExceptionListener listener = (RemoteExceptionListener) _listeners.get(i);
081    
082                    listener.remoteExceptionDidOccur(event);
083                }
084            }
085            finally
086            {
087                _locked = false;
088            }
089    
090        }
091    
092    }