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The Core Camel Java DSL based router
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.camel.component.seda;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.ExecutorService;
import org.apache.camel.AsyncEndpoint;
import org.apache.camel.Component;
import org.apache.camel.Consumer;
import org.apache.camel.Exchange;
import org.apache.camel.MultipleConsumersSupport;
import org.apache.camel.PollingConsumer;
import org.apache.camel.Processor;
import org.apache.camel.Producer;
import org.apache.camel.WaitForTaskToComplete;
import org.apache.camel.api.management.ManagedAttribute;
import org.apache.camel.api.management.ManagedOperation;
import org.apache.camel.api.management.ManagedResource;
import org.apache.camel.impl.DefaultEndpoint;
import org.apache.camel.processor.MulticastProcessor;
import org.apache.camel.spi.BrowsableEndpoint;
import org.apache.camel.spi.Metadata;
import org.apache.camel.spi.UriEndpoint;
import org.apache.camel.spi.UriParam;
import org.apache.camel.spi.UriPath;
import org.apache.camel.util.ServiceHelper;
import org.apache.camel.util.URISupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The seda component provides asynchronous call to another endpoint from any CamelContext in the same JVM.
*/
@ManagedResource(description = "Managed SedaEndpoint")
@UriEndpoint(firstVersion = "1.1.0", scheme = "seda", title = "SEDA", syntax = "seda:name", consumerClass = SedaConsumer.class, label = "core,endpoint")
public class SedaEndpoint extends DefaultEndpoint implements AsyncEndpoint, BrowsableEndpoint, MultipleConsumersSupport {
private static final Logger LOG = LoggerFactory.getLogger(SedaEndpoint.class);
private final Set producers = new CopyOnWriteArraySet();
private final Set consumers = new CopyOnWriteArraySet();
private volatile MulticastProcessor consumerMulticastProcessor;
private volatile boolean multicastStarted;
private volatile ExecutorService multicastExecutor;
@UriPath(description = "Name of queue") @Metadata(required = "true")
private String name;
@UriParam(label = "advanced", description = "Define the queue instance which will be used by the endpoint")
private BlockingQueue queue;
@UriParam(defaultValue = "" + Integer.MAX_VALUE)
private int size = Integer.MAX_VALUE;
@UriParam(label = "consumer", defaultValue = "1")
private int concurrentConsumers = 1;
@UriParam(label = "consumer,advanced", defaultValue = "true")
private boolean limitConcurrentConsumers = true;
@UriParam(label = "consumer,advanced")
private boolean multipleConsumers;
@UriParam(label = "consumer,advanced")
private boolean purgeWhenStopping;
@UriParam(label = "consumer,advanced", defaultValue = "1000")
private int pollTimeout = 1000;
@UriParam(label = "producer", defaultValue = "IfReplyExpected")
private WaitForTaskToComplete waitForTaskToComplete = WaitForTaskToComplete.IfReplyExpected;
@UriParam(label = "producer", defaultValue = "30000")
private long timeout = 30000;
@UriParam(label = "producer")
private boolean blockWhenFull;
@UriParam(label = "producer")
private boolean failIfNoConsumers;
@UriParam(label = "producer")
private boolean discardIfNoConsumers;
private BlockingQueueFactory queueFactory;
public SedaEndpoint() {
queueFactory = new LinkedBlockingQueueFactory();
}
public SedaEndpoint(String endpointUri, Component component, BlockingQueue queue) {
this(endpointUri, component, queue, 1);
}
public SedaEndpoint(String endpointUri, Component component, BlockingQueue queue, int concurrentConsumers) {
this(endpointUri, component, concurrentConsumers);
this.queue = queue;
if (queue != null) {
this.size = queue.remainingCapacity();
}
queueFactory = new LinkedBlockingQueueFactory();
getComponent().registerQueue(this, queue);
}
public SedaEndpoint(String endpointUri, Component component, BlockingQueueFactory queueFactory, int concurrentConsumers) {
this(endpointUri, component, concurrentConsumers);
this.queueFactory = queueFactory;
}
private SedaEndpoint(String endpointUri, Component component, int concurrentConsumers) {
super(endpointUri, component);
this.concurrentConsumers = concurrentConsumers;
}
@Override
public SedaComponent getComponent() {
return (SedaComponent) super.getComponent();
}
public Producer createProducer() throws Exception {
return new SedaProducer(this, getWaitForTaskToComplete(), getTimeout(), isBlockWhenFull());
}
public Consumer createConsumer(Processor processor) throws Exception {
if (getComponent() != null) {
// all consumers must match having the same multipleConsumers options
String key = getComponent().getQueueKey(getEndpointUri());
QueueReference ref = getComponent().getQueueReference(key);
if (ref != null && ref.getMultipleConsumers() != isMultipleConsumers()) {
// there is already a multiple consumers, so make sure they matches
throw new IllegalArgumentException("Cannot use existing queue " + key + " as the existing queue multiple consumers "
+ ref.getMultipleConsumers() + " does not match given multiple consumers " + multipleConsumers);
}
}
Consumer answer = createNewConsumer(processor);
configureConsumer(answer);
return answer;
}
protected SedaConsumer createNewConsumer(Processor processor) {
return new SedaConsumer(this, processor);
}
@Override
public PollingConsumer createPollingConsumer() throws Exception {
SedaPollingConsumer answer = new SedaPollingConsumer(this);
configureConsumer(answer);
return answer;
}
public synchronized BlockingQueue getQueue() {
if (queue == null) {
// prefer to lookup queue from component, so if this endpoint is re-created or re-started
// then the existing queue from the component can be used, so new producers and consumers
// can use the already existing queue referenced from the component
if (getComponent() != null) {
// use null to indicate default size (= use what the existing queue has been configured with)
Integer size = getSize() == Integer.MAX_VALUE ? null : getSize();
QueueReference ref = getComponent().getOrCreateQueue(this, size, isMultipleConsumers(), queueFactory);
queue = ref.getQueue();
String key = getComponent().getQueueKey(getEndpointUri());
LOG.info("Endpoint {} is using shared queue: {} with size: {}", new Object[]{this, key, ref.getSize() != null ? ref.getSize() : Integer.MAX_VALUE});
// and set the size we are using
if (ref.getSize() != null) {
setSize(ref.getSize());
}
} else {
// fallback and create queue (as this endpoint has no component)
queue = createQueue();
LOG.info("Endpoint {} is using queue: {} with size: {}", new Object[]{this, getEndpointUri(), getSize()});
}
}
return queue;
}
protected BlockingQueue createQueue() {
if (size > 0) {
return queueFactory.create(size);
} else {
return queueFactory.create();
}
}
/**
* Get's the {@link QueueReference} for the this endpoint.
* @return the reference, or null if no queue reference exists.
*/
public synchronized QueueReference getQueueReference() {
String key = getComponent().getQueueKey(getEndpointUri());
QueueReference ref = getComponent().getQueueReference(key);
return ref;
}
protected synchronized MulticastProcessor getConsumerMulticastProcessor() throws Exception {
if (!multicastStarted && consumerMulticastProcessor != null) {
// only start it on-demand to avoid starting it during stopping
ServiceHelper.startService(consumerMulticastProcessor);
multicastStarted = true;
}
return consumerMulticastProcessor;
}
protected synchronized void updateMulticastProcessor() throws Exception {
// only needed if we support multiple consumers
if (!isMultipleConsumersSupported()) {
return;
}
// stop old before we create a new
if (consumerMulticastProcessor != null) {
ServiceHelper.stopService(consumerMulticastProcessor);
consumerMulticastProcessor = null;
}
int size = getConsumers().size();
if (size >= 1) {
if (multicastExecutor == null) {
// create multicast executor as we need it when we have more than 1 processor
multicastExecutor = getCamelContext().getExecutorServiceManager().newDefaultThreadPool(this, URISupport.sanitizeUri(getEndpointUri()) + "(multicast)");
}
// create list of consumers to multicast to
List processors = new ArrayList(size);
for (SedaConsumer consumer : getConsumers()) {
processors.add(consumer.getProcessor());
}
// create multicast processor
multicastStarted = false;
consumerMulticastProcessor = new MulticastProcessor(getCamelContext(), processors, null,
true, multicastExecutor, false, false, false,
0, null, false, false);
}
}
/**
* Define the queue instance which will be used by the endpoint.
*
* This option is only for rare use-cases where you want to use a custom queue instance.
*/
public void setQueue(BlockingQueue queue) {
this.queue = queue;
this.size = queue.remainingCapacity();
}
@ManagedAttribute(description = "Queue max capacity")
public int getSize() {
return size;
}
/**
* The maximum capacity of the SEDA queue (i.e., the number of messages it can hold).
*/
public void setSize(int size) {
this.size = size;
}
@ManagedAttribute(description = "Current queue size")
public int getCurrentQueueSize() {
return queue.size();
}
/**
* Whether a thread that sends messages to a full SEDA queue will block until the queue's capacity is no longer exhausted.
* By default, an exception will be thrown stating that the queue is full.
* By enabling this option, the calling thread will instead block and wait until the message can be accepted.
*/
public void setBlockWhenFull(boolean blockWhenFull) {
this.blockWhenFull = blockWhenFull;
}
@ManagedAttribute(description = "Whether the caller will block sending to a full queue")
public boolean isBlockWhenFull() {
return blockWhenFull;
}
/**
* Number of concurrent threads processing exchanges.
*/
public void setConcurrentConsumers(int concurrentConsumers) {
this.concurrentConsumers = concurrentConsumers;
}
@ManagedAttribute(description = "Number of concurrent consumers")
public int getConcurrentConsumers() {
return concurrentConsumers;
}
@ManagedAttribute
public boolean isLimitConcurrentConsumers() {
return limitConcurrentConsumers;
}
/**
* Whether to limit the number of concurrentConsumers to the maximum of 500.
* By default, an exception will be thrown if an endpoint is configured with a greater number. You can disable that check by turning this option off.
*/
public void setLimitConcurrentConsumers(boolean limitConcurrentConsumers) {
this.limitConcurrentConsumers = limitConcurrentConsumers;
}
public WaitForTaskToComplete getWaitForTaskToComplete() {
return waitForTaskToComplete;
}
/**
* Option to specify whether the caller should wait for the async task to complete or not before continuing.
* The following three options are supported: Always, Never or IfReplyExpected.
* The first two values are self-explanatory.
* The last value, IfReplyExpected, will only wait if the message is Request Reply based.
* The default option is IfReplyExpected.
*/
public void setWaitForTaskToComplete(WaitForTaskToComplete waitForTaskToComplete) {
this.waitForTaskToComplete = waitForTaskToComplete;
}
@ManagedAttribute
public long getTimeout() {
return timeout;
}
/**
* Timeout (in milliseconds) before a SEDA producer will stop waiting for an asynchronous task to complete.
* You can disable timeout by using 0 or a negative value.
*/
public void setTimeout(long timeout) {
this.timeout = timeout;
}
@ManagedAttribute
public boolean isFailIfNoConsumers() {
return failIfNoConsumers;
}
/**
* Whether the producer should fail by throwing an exception, when sending to a queue with no active consumers.
*
* Only one of the options discardIfNoConsumers and failIfNoConsumers can be enabled at the same time.
*/
public void setFailIfNoConsumers(boolean failIfNoConsumers) {
this.failIfNoConsumers = failIfNoConsumers;
}
@ManagedAttribute
public boolean isDiscardIfNoConsumers() {
return discardIfNoConsumers;
}
/**
* Whether the producer should discard the message (do not add the message to the queue), when sending to a queue with no active consumers.
*
* Only one of the options discardIfNoConsumers and failIfNoConsumers can be enabled at the same time.
*/
public void setDiscardIfNoConsumers(boolean discardIfNoConsumers) {
this.discardIfNoConsumers = discardIfNoConsumers;
}
@ManagedAttribute
public boolean isMultipleConsumers() {
return multipleConsumers;
}
/**
* Specifies whether multiple consumers are allowed. If enabled, you can use SEDA for Publish-Subscribe messaging.
* That is, you can send a message to the SEDA queue and have each consumer receive a copy of the message.
* When enabled, this option should be specified on every consumer endpoint.
*/
public void setMultipleConsumers(boolean multipleConsumers) {
this.multipleConsumers = multipleConsumers;
}
@ManagedAttribute
public int getPollTimeout() {
return pollTimeout;
}
/**
* The timeout used when polling. When a timeout occurs, the consumer can check whether it is allowed to continue running.
* Setting a lower value allows the consumer to react more quickly upon shutdown.
*/
public void setPollTimeout(int pollTimeout) {
this.pollTimeout = pollTimeout;
}
@ManagedAttribute
public boolean isPurgeWhenStopping() {
return purgeWhenStopping;
}
/**
* Whether to purge the task queue when stopping the consumer/route.
* This allows to stop faster, as any pending messages on the queue is discarded.
*/
public void setPurgeWhenStopping(boolean purgeWhenStopping) {
this.purgeWhenStopping = purgeWhenStopping;
}
public boolean isSingleton() {
return true;
}
/**
* Returns the current pending exchanges
*/
public List getExchanges() {
return new ArrayList(getQueue());
}
@ManagedAttribute
public boolean isMultipleConsumersSupported() {
return isMultipleConsumers();
}
/**
* Purges the queue
*/
@ManagedOperation(description = "Purges the seda queue")
public void purgeQueue() {
LOG.debug("Purging queue with {} exchanges", queue.size());
queue.clear();
}
/**
* Returns the current active consumers on this endpoint
*/
public Set getConsumers() {
return consumers;
}
/**
* Returns the current active producers on this endpoint
*/
public Set getProducers() {
return new HashSet(producers);
}
void onStarted(SedaProducer producer) {
producers.add(producer);
}
void onStopped(SedaProducer producer) {
producers.remove(producer);
}
void onStarted(SedaConsumer consumer) throws Exception {
consumers.add(consumer);
if (isMultipleConsumers()) {
updateMulticastProcessor();
}
}
void onStopped(SedaConsumer consumer) throws Exception {
consumers.remove(consumer);
if (isMultipleConsumers()) {
updateMulticastProcessor();
}
}
public boolean hasConsumers() {
return this.consumers.size() > 0;
}
@Override
protected void doStart() throws Exception {
super.doStart();
// force creating queue when starting
if (queue == null) {
queue = getQueue();
}
// special for unit testing where we can set a system property to make seda poll faster
// and therefore also react faster upon shutdown, which makes overall testing faster of the Camel project
String override = System.getProperty("CamelSedaPollTimeout", "" + getPollTimeout());
setPollTimeout(Integer.valueOf(override));
}
@Override
public void stop() throws Exception {
if (getConsumers().isEmpty()) {
super.stop();
} else {
LOG.debug("There is still active consumers.");
}
}
@Override
public void shutdown() throws Exception {
if (shutdown.get()) {
LOG.trace("Service already shut down");
return;
}
// notify component we are shutting down this endpoint
if (getComponent() != null) {
getComponent().onShutdownEndpoint(this);
}
if (getConsumers().isEmpty()) {
super.shutdown();
} else {
LOG.debug("There is still active consumers.");
}
}
@Override
protected void doShutdown() throws Exception {
// shutdown thread pool if it was in use
if (multicastExecutor != null) {
getCamelContext().getExecutorServiceManager().shutdownNow(multicastExecutor);
multicastExecutor = null;
}
// clear queue, as we are shutdown, so if re-created then the queue must be updated
queue = null;
}
}