org.springframework.integration.endpoint.EventDrivenConsumer Maven / Gradle / Ivy
/*
* Copyright 2002-2019 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.integration.endpoint;
import org.springframework.context.Lifecycle;
import org.springframework.integration.core.MessageProducer;
import org.springframework.integration.router.MessageRouter;
import org.springframework.integration.support.context.NamedComponent;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.SubscribableChannel;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
/**
* Message Endpoint that connects any {@link MessageHandler} implementation to a {@link SubscribableChannel}.
*
* @author Mark Fisher
* @author Oleg Zhurakousky
* @author Gary Russell
*/
public class EventDrivenConsumer extends AbstractEndpoint implements IntegrationConsumer {
private final SubscribableChannel inputChannel;
private final MessageHandler handler;
public EventDrivenConsumer(SubscribableChannel inputChannel, MessageHandler handler) {
Assert.notNull(inputChannel, "inputChannel must not be null");
Assert.notNull(handler, "handler must not be null");
this.inputChannel = inputChannel;
this.handler = handler;
this.setPhase(Integer.MIN_VALUE);
}
@Override
public MessageChannel getInputChannel() {
return this.inputChannel;
}
@Override
public MessageChannel getOutputChannel() {
if (this.handler instanceof MessageProducer) {
return ((MessageProducer) this.handler).getOutputChannel();
}
else if (this.handler instanceof MessageRouter) {
return ((MessageRouter) this.handler).getDefaultOutputChannel();
}
else {
return null;
}
}
@Override
public MessageHandler getHandler() {
return this.handler;
}
@Override
protected void doStart() {
this.logComponentSubscriptionEvent(true);
this.inputChannel.subscribe(this.handler);
if (this.handler instanceof Lifecycle) {
((Lifecycle) this.handler).start();
}
}
@Override
protected void doStop() {
this.logComponentSubscriptionEvent(false);
this.inputChannel.unsubscribe(this.handler);
if (this.handler instanceof Lifecycle) {
((Lifecycle) this.handler).stop();
}
}
private void logComponentSubscriptionEvent(boolean add) {
if (this.handler instanceof NamedComponent && this.inputChannel instanceof NamedComponent) {
String channelName = ((NamedComponent) this.inputChannel).getComponentName();
String componentType = ((NamedComponent) this.handler).getComponentType();
componentType = StringUtils.hasText(componentType) ? componentType : "";
String componentName = getComponentName();
componentName = (StringUtils.hasText(componentName) && componentName.contains("#")) ? "" : ":" + componentName;
StringBuffer buffer = new StringBuffer();
buffer.append("{" + componentType + componentName + "} as a subscriber to the '" + channelName + "' channel");
if (add) {
buffer.insert(0, "Adding ");
}
else {
buffer.insert(0, "Removing ");
}
logger.info(buffer.toString());
}
}
}