001package ca.uhn.fhir.jpa.subscription.channel.subscription;
002
003/*-
004 * #%L
005 * HAPI FHIR Subscription Server
006 * %%
007 * Copyright (C) 2014 - 2021 Smile CDR, Inc.
008 * %%
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *      http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 * #L%
021 */
022
023import ca.uhn.fhir.jpa.subscription.channel.api.IChannelReceiver;
024import org.apache.commons.lang3.Validate;
025import org.springframework.messaging.Message;
026import org.springframework.messaging.MessageHandler;
027import org.springframework.messaging.SubscribableChannel;
028import org.springframework.messaging.support.AbstractSubscribableChannel;
029import org.springframework.messaging.support.ChannelInterceptor;
030
031import java.util.Set;
032
033public class BroadcastingSubscribableChannelWrapper extends AbstractSubscribableChannel implements IChannelReceiver {
034
035    private final IChannelReceiver myWrappedChannel;
036    private final MessageHandler myHandler;
037
038    public BroadcastingSubscribableChannelWrapper(IChannelReceiver theChannel) {
039        myHandler = message -> send(message);
040        theChannel.subscribe(myHandler);
041        myWrappedChannel = theChannel;
042    }
043
044    public SubscribableChannel getWrappedChannel() {
045        return myWrappedChannel;
046    }
047
048    @Override
049    protected boolean sendInternal(Message<?> theMessage, long timeout) {
050        Set<MessageHandler> subscribers = getSubscribers();
051        Validate.isTrue(subscribers.size() > 0, "Channel has zero subscribers");
052        for (MessageHandler next : subscribers) {
053            next.handleMessage(theMessage);
054        }
055        return true;
056    }
057
058    @Override
059    public void destroy() throws Exception {
060        myWrappedChannel.destroy();
061        myWrappedChannel.unsubscribe(myHandler);
062    }
063
064    @Override
065    public void addInterceptor(ChannelInterceptor interceptor) {
066        super.addInterceptor(interceptor);
067        myWrappedChannel.addInterceptor(interceptor);
068    }
069
070
071    @Override
072    public String getName() {
073        return myWrappedChannel.getName();
074    }
075}