/*
* Copyright 2002-2016 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
*
* http://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.config.xml;
import org.w3c.dom.Element;
import org.springframework.beans.factory.config.TypedStringValue;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.channel.ExecutorChannel;
import org.springframework.integration.channel.FixedSubscriberChannel;
import org.springframework.integration.channel.PriorityChannel;
import org.springframework.integration.channel.QueueChannel;
import org.springframework.integration.channel.RendezvousChannel;
import org.springframework.integration.store.MessageGroupQueue;
import org.springframework.util.StringUtils;
import org.springframework.util.xml.DomUtils;
/**
* Parser for the <channel> element.
*
* @author Mark Fisher
* @author Iwein Fuld
* @author Oleg Zhurakousky
* @author Gary Russell
* @author Artem Bilan
* @author Manuel Jordan
*/
public class PointToPointChannelParser extends AbstractChannelParser {
@Override
protected BeanDefinitionBuilder buildBeanDefinition(Element element, ParserContext parserContext) {
BeanDefinitionBuilder builder = null;
Element queueElement = null;
String fixedSubscriberChannel = element.getAttribute("fixed-subscriber");
boolean isFixedSubscriber = "true".equals(fixedSubscriberChannel.trim().toLowerCase());
// configure a queue-based channel if any queue sub-element is defined
String channel = element.getAttribute(ID_ATTRIBUTE);
if ((queueElement = DomUtils.getChildElementByTagName(element, "queue")) != null) {
builder = BeanDefinitionBuilder.genericBeanDefinition(QueueChannel.class);
boolean hasStoreRef = this.parseStoreRef(builder, queueElement, channel, false);
boolean hasQueueRef = this.parseQueueRef(builder, queueElement);
if (!hasStoreRef || !hasQueueRef) {
boolean hasCapacity = this.parseQueueCapacity(builder, queueElement);
if (hasCapacity && hasQueueRef) {
parserContext.getReaderContext().error(
"The 'capacity' attribute is not allowed when providing a 'ref' to a custom queue.",
element);
}
if (hasCapacity && hasStoreRef) {
parserContext.getReaderContext().error(
"The 'capacity' attribute is not allowed" +
" when providing a 'message-store' to a custom MessageGroupStore.",
element);
}
}
if (hasStoreRef && hasQueueRef) {
parserContext.getReaderContext().error(
"The 'message-store' attribute is not allowed when providing a 'ref' to a custom queue.",
element);
}
}
else if ((queueElement = DomUtils.getChildElementByTagName(element, "priority-queue")) != null) {
builder = BeanDefinitionBuilder.genericBeanDefinition(PriorityChannel.class);
boolean hasCapacity = this.parseQueueCapacity(builder, queueElement);
String comparatorRef = queueElement.getAttribute("comparator");
if (StringUtils.hasText(comparatorRef)) {
builder.addConstructorArgReference(comparatorRef);
}
if (parseStoreRef(builder, queueElement, channel, true)) {
if (StringUtils.hasText(comparatorRef)) {
parserContext.getReaderContext().error(
"The 'message-store' attribute is not allowed" +
" when providing a 'comparator' to a priority queue.",
element);
}
if (hasCapacity) {
parserContext.getReaderContext().error("The 'capacity' attribute is not allowed"
+ " when providing a 'message-store' to a custom MessageGroupStore.", element);
}
}
}
else if ((queueElement = DomUtils.getChildElementByTagName(element, "rendezvous-queue")) != null) {
builder = BeanDefinitionBuilder.genericBeanDefinition(RendezvousChannel.class);
}
Element dispatcherElement = DomUtils.getChildElementByTagName(element, "dispatcher");
// verify that a dispatcher is not provided if a queue sub-element exists
if (queueElement != null && dispatcherElement != null) {
parserContext.getReaderContext().error(
"The 'dispatcher' sub-element and any queue sub-element are mutually exclusive.", element);
return null;
}
if (queueElement != null) {
if (isFixedSubscriber) {
parserContext.getReaderContext().error(
"The 'fixed-subscriber' attribute is not allowed when a <queue/> child element is present.",
element);
}
return builder;
}
if (dispatcherElement == null) {
// configure the default DirectChannel with a RoundRobinLoadBalancingStrategy
builder = BeanDefinitionBuilder.genericBeanDefinition(isFixedSubscriber ? FixedSubscriberChannel.class
: DirectChannel.class);
}
else {
if (isFixedSubscriber) {
parserContext.getReaderContext().error(
"The 'fixed-subscriber' attribute is not allowed" +
" when a <dispatcher/> child element is present.",
element);
}
// configure either an ExecutorChannel or DirectChannel based on existence of 'task-executor'
String taskExecutor = dispatcherElement.getAttribute("task-executor");
if (StringUtils.hasText(taskExecutor)) {
builder = BeanDefinitionBuilder.genericBeanDefinition(ExecutorChannel.class);
builder.addConstructorArgReference(taskExecutor);
}
else {
builder = BeanDefinitionBuilder.genericBeanDefinition(DirectChannel.class);
}
// unless the 'load-balancer' attribute is explicitly set to 'none'
// or 'load-balancer-ref' is explicitly configured,
// configure the default RoundRobinLoadBalancingStrategy
String loadBalancer = dispatcherElement.getAttribute("load-balancer");
String loadBalancerRef = dispatcherElement.getAttribute("load-balancer-ref");
if (StringUtils.hasText(loadBalancer) && StringUtils.hasText(loadBalancerRef)) {
parserContext.getReaderContext().error("'load-balancer' and 'load-balancer-ref' are mutually exclusive",
element);
}
if (StringUtils.hasText(loadBalancerRef)) {
builder.addConstructorArgReference(loadBalancerRef);
}
else {
if ("none".equals(loadBalancer)) {
builder.addConstructorArgValue(null);
}
}
IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, dispatcherElement, "failover");
IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, dispatcherElement, "max-subscribers");
}
return builder;
}
private boolean parseQueueCapacity(BeanDefinitionBuilder builder, Element queueElement) {
String capacity = queueElement.getAttribute("capacity");
if (StringUtils.hasText(capacity)) {
builder.addConstructorArgValue(capacity);
return true;
}
return false;
}
private boolean parseQueueRef(BeanDefinitionBuilder builder, Element queueElement) {
String queueRef = queueElement.getAttribute("ref");
if (StringUtils.hasText(queueRef)) {
builder.addConstructorArgReference(queueRef);
return true;
}
return false;
}
private boolean parseStoreRef(BeanDefinitionBuilder builder, Element queueElement, String channel,
boolean priority) {
String storeRef = queueElement.getAttribute("message-store");
if (StringUtils.hasText(storeRef)) {
BeanDefinitionBuilder queueBuilder = BeanDefinitionBuilder
.genericBeanDefinition(MessageGroupQueue.class);
queueBuilder.addConstructorArgReference(storeRef);
queueBuilder.addConstructorArgValue(new TypedStringValue(storeRef).getValue() + ":" + channel);
queueBuilder.addPropertyValue("priority", priority);
parseQueueCapacity(queueBuilder, queueElement);
builder.addConstructorArgValue(queueBuilder.getBeanDefinition());
return true;
}
return false;
}
}