org.springframework.integration.transformer.MessageTransformingHandler 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.transformer;
import java.util.Collection;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.context.Lifecycle;
import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
import org.springframework.integration.support.context.NamedComponent;
import org.springframework.messaging.Message;
import org.springframework.util.Assert;
/**
* A reply-producing {@link org.springframework.messaging.MessageHandler}
* that delegates to a
* {@link Transformer} instance to modify the received {@link Message}
* and sends the result to its output channel.
*
* @author Mark Fisher
* @author Oleg Zhurakousky
* @author Artem Bilan
* @author Gary Russell
*/
public class MessageTransformingHandler extends AbstractReplyProducingMessageHandler implements Lifecycle {
private final Transformer transformer;
/**
* Create a {@link MessageTransformingHandler} instance that delegates to
* the provided {@link Transformer}.
*
* @param transformer The transformer.
*/
public MessageTransformingHandler(Transformer transformer) {
Assert.notNull(transformer, "transformer must not be null");
this.transformer = transformer;
this.setRequiresReply(true);
}
@Override
public String getComponentType() {
return (this.transformer instanceof NamedComponent) ?
((NamedComponent) this.transformer).getComponentType() : "transformer";
}
@Override
public void addNotPropagatedHeaders(String... headers) {
super.addNotPropagatedHeaders(headers);
populateNotPropagatedHeadersIfAny();
}
@Override
protected void doInit() {
if (this.getBeanFactory() != null && this.transformer instanceof BeanFactoryAware) {
((BeanFactoryAware) this.transformer).setBeanFactory(this.getBeanFactory());
}
populateNotPropagatedHeadersIfAny();
}
private void populateNotPropagatedHeadersIfAny() {
Collection notPropagatedHeaders = getNotPropagatedHeaders();
if (this.transformer instanceof AbstractMessageProcessingTransformer && !notPropagatedHeaders.isEmpty()) {
((AbstractMessageProcessingTransformer) this.transformer)
.setNotPropagatedHeaders(notPropagatedHeaders.toArray(new String[0]));
}
}
@Override
public void start() {
if (this.transformer instanceof Lifecycle) {
((Lifecycle) this.transformer).start();
}
}
@Override
public void stop() {
if (this.transformer instanceof Lifecycle) {
((Lifecycle) this.transformer).stop();
}
}
@Override
public boolean isRunning() {
return !(this.transformer instanceof Lifecycle) || ((Lifecycle) this.transformer).isRunning();
}
@Override
protected Object handleRequestMessage(Message message) {
try {
return this.transformer.transform(message);
}
catch (Exception e) {
if (e instanceof MessageTransformationException) {
throw (MessageTransformationException) e;
}
throw new MessageTransformationException(message, "Failed to transform Message", e);
}
}
@Override
protected boolean shouldCopyRequestHeaders() {
return false;
}
}