JMS Component

The JMS component allows messages to be sent to a JMS Queue or Topic; or messages to be consumed from a JMS Queue or Topic. The implementation of the JMS Component uses Spring's JMS support for declarative transactions, using Spring's JmsTemplate for sending and a MessageListenerContainer for consuming.

Using ActiveMQ If you are using Apache ActiveMQ you should prefer to use the ActiveMQ component as it has been particularly optimized for ActiveMQ. All the options and samples on this page applies as well for ActiveMQ component.

URI format

jms:[topic:]destinationName?options

So for example to send to queue FOO.BAR you would use

jms:FOO.BAR

You can be completely specific if you wish via

jms:queue:FOO.BAR

If you want to send to a topic called Stocks.Prices then you would use

jms:topic:Stocks.Prices

Using Temporary Destinations

As of 1.4.0 of Camel you can use temporary queues using the following URL format

jms:temp:queue:foo

or temporary topics as

jms:temp:topic:bar

Where foo and bar, the text after the String jms:temp:queue: or jms:temp:topic:, are the names of the destinations. This enables multiple routes or processors or beans to refer to the same temporary destination. e.g. you can create 3 temporary destinations and use them in routes as inputs or outputs by referring to them by name.

Notes

If you are using ActiveMQ Note that the JMS component reuses Spring 2's JmsTemplate for sending messages. This is not ideal for use in a non-J2EE container and typically requires some caching JMS provider to avoid performance being lousy. So if you intent to use Apache ActiveMQ as your Message Broker - which is a good choice as ActiveMQ rocks , then we recommend that you either use the ActiveMQ component which is already configured to use ActiveMQ efficiently use the PoolingConnectionFactory in ActiveMQ

If you wish to use durable topic subscriptions, you need to specify both clientId and durableSubscriptionName. Note that the value of the clientId must be unique and can only be used by a single JMS connection instance in your entire network. You may prefer to use Virtual Topics instead to avoid this limitation. More background on durable messaging here.

When using message headers; the JMS specification states that header names must be valid Java identifiers. So by default camel will ignore any headers which do not match this rule. So try name your headers as if they are valid Java identifiers. One added bonus of this is that you can then use your headers inside a JMS Selector - which uses SQL92 syntax which mandates Java identifier syntax for headers.

From Camel 1.4 a simple strategy for mapping headers names is used by default. The strategy is to replace any dots in the headername with underscore, and vice-versa when the header name is restored from the JMS message that was sent over the wire. What does this means? No more loosing method names to invoke on a bean component, no more loosing the filename header for the File Component etc.

Current header name strategy used for accepting header names in Camel:

• replace all dots with underscores (e.g. org.apache.camel.MethodName => org_apache_camel_MethodName)
• test if the name is a valid java identifier using the JDK core classes
• if test success then the header is added and sent over the wire, if not its dropped (logged at DEBUG level)

For Consuming Messages cacheLevelName settings are vital! If you are using Spring before 2.5.1 and Camel before 1.3.0 then you might want to set the cacheLevelName to be CACHE_CONSUMER for maximum performance. Due to a bug in earlier Spring versions causing a lack of transactional integrity, previous versions of Camel and Camel versions from 1.3.0 onwwards when used with earlier Spring versions than 2.5.1 will default to use CACHE_CONNECTION. See the JIRAs CAMEL-163 and CAMEL-294. Also if you are using XA or running in a J2EE container then you may want to set the cacheLevelName to be CACHE_NONE as we have seen using JBoss with TibCo EMS and JTA/XA you must disable caching. Another end user reports issue with using WebSphere MQ 6.0.2.5, Camel 1.6.0 and Spring 2.5.6. Not running XA or inside a J2EE Container, but the cacheLevelName=CACHE_NONE seems to have solved the problem with WebSphere MQ. See also more about JmsTemplate gotchas.

Options

You can configure lots of different properties on the JMS endpoint which map to properties on the JMSConfiguration POJO. Notice: Many of these properties maps to properties on Spring JMS that Camel uses for sending and receiving messages. So you can get more information about these properties by consulting the Spring documentation.

Option	Default Value	Description
acceptMessagesWhileStopping	false	Should the consumer accept messages while it is stopping
acknowledgementModeName	"AUTO_ACKNOWLEDGE"	The JMS acknowledgement name which is one of: TRANSACTED, CLIENT_ACKNOWLEDGE, AUTO_ACKNOWLEDGE, DUPS_OK_ACKNOWLEDGE
acknowledgementMode	-1	The JMS acknowledgement mode defined as an Integer. Allows to set vendor-specific extensions to the acknowledgment mode. For the regular modes prefer to use the acknowledgementModeName instead.
alwaysCopyMessage	false	If true then Camel will always make a JMS message copy of the message when it's passed to the producer for sending. Copying the message is needed in some situations such as when a replyToDestinationSelectorName is set (Camel will by the way set the alwaysCopyMessage to true if a replyToDestinationSelectorName is set)
autoStartup	true	Should the consumer container auto-startup
cacheLevelName	"CACHE_CONSUMER"	Sets the cache level by name for the underlying JMS resources. Possible values are: CACHE_AUTO, CACHE_CONNECTION, CACHE_CONSUMER, CACHE_NONE and CACHE_SESSION. See the Spring documentation. And see the warning above.
cacheLevel	-1	Sets the cache level by id for the underlying JMS resources
clientId	null	Sets the JMS client ID to use. Note that this value if specified must be unique and can only be used by a single JMS connection instance. Its typically only required for durable topic subscriptions. You may prefer to use Virtual Topics instead
consumerType	Default	The consumer type to use, either: Simple, Default or ServerSessionPool. The consumer type determines which Spring JMS listener should be used. Default will use org.springframework.jms.listener.DefaultMessageListenerContainer. Simple will use org.springframework.jms.listener.SimpleMessageListenerContainer and ServerSessionPool will use org.springframework.jms.listener.serversession.ServerSessionMessageListenerContainer. If option useVersion102=true then Camel will of course use the JMS 1.0.2 Spring classes instead. ServerSessionPool is @deprecated and will be removed in Camel 2.0.
concurrentConsumers	1	Specifies the default number of concurrent consumers
connectionFactory	null	The default JMS connection factory to use for the listenerConnectionFactory and templateConnectionFactory if neither are specified
deliveryMode	2	Specifies the delivery mode when sending. 1 = non persistent. 2 = persistent.
deliveryPersistent	true	Is persistent delivery used by default?
destination	null	(2.0 onwards) specifies the JMS Destination object to use on this endpoint
destinationName	null	(2.0 onwards) specifies the JMS destination name to use on this endpoint
disableReplyTo	false	Do you want to ignore the JMSReplyTo header and so treat messages as InOnly by default and not send a reply back?
durableSubscriptionName	null	The durable subscriber name for specifying durable topic subscriptions
eagerLoadingOfProperties	false	Enables eager loading of JMS properties as soon as a message is received which generally is inefficient as the JMS properties may not be required but sometimes can catch early any issues with the underlying JMS provider and the use of JMS properties. Can be used for testing purpose to ensure JMS properties can be understood and handled correctly.
exceptionListener	null	The JMS Exception Listener used to be notified of any underlying JMS exceptions
explicitQosEnabled	false	Set if the deliveryMode, priority or timeToLive should be used when sending messages. This option is from Spring JmsTemplate. The deliveryMode, priority and timeToLive is options set on this endpoint that is used. As opposed to preserveMessageQos that uses options exclusively from the Camel IN message headers only.
exposeListenerSession	true	Set if the listener session should be exposed when consuming messages
idleTaskExecutionLimit	1	Specify the limit for idle executions of a receive task, not having received any message within its execution. If this limit is reached, the task will shut down and leave receiving to other executing tasks (in case of dynamic scheduling; see the "maxConcurrentConsumers" setting).
jmsMessageType	null	Camel 2.0: Allows you to force to use a specific javax.jms.Message implementation for sending a jms message. Possible values: Bytes, Map, Object, Stream, Text. By default Camel will determine from the IN body type which Jms message type to use. This option allows you to choose it.
jmsOperations	null	Allow to use your own implementation of the org.springframework.jms.core.JmsOperations interface. Camel uses JmsTemplate as default. Can be used for testing purpose, but not used much as stated in the spring API docs.
jmsKeyFormatStrategy	default	Camel 2.0: Pluggable strategy for encoding and decoding JMS keys so they can be compliant with the JMS spec. Camel provides two implementations out of the box: default and passthrough. Default will safely marshal dots and hyphens (. and -). Passthrough lets the key as is. Can be used for JMS brokers which do not care about JMS header keys containing illegal characters. You can provide you own implementation of the org.apache.camel.component.jms.JmsKeyFormatStrategy and refer to it using the # notation.
lazyCreateTransactionManager	true	(new added in Camel 2.0)If it is true , Camel will create a JmsTransactionManager if there is no transactionManager injected when the transacted is true
listenerConnectionFactory	null	The JMS connection factory used for consuming messages
maxConcurrentConsumers	1	Specifies the maximum number of concurrent consumers
maxMessagesPerTask	1	The number of messages per task
messageConverter	null	The Spring Message Converter
messageIdEnabled	true	When sending, should message IDs be added
messageTimestampEnabled	true	Should timestamps be enabled by default on sending messages
password	null	The password which is set for the connector factory
priority	-1	Values of > 1 specify the message priority when sending, if the explicitQosEnabled property is specified (with 0 as the lowest priority and 9 as the highest)
preserveMessageQos	false	Camel 2.0: Set to true if you want to send message using the QoS settings specified on the message, instead of the QoS settings on the JMS endpoint. The following 3 headers is used JMSPriority, JMSDeliveryMode and JMSExpiration. You can provide all or only some of them. If not provided then Camel will fallback to use the values from this endpoint instead. So when using this option the headers will override the values from the endpoint. The option explicitQosEnabled on the other hand will only use options set on the endpoint and not values from the message header.
pubSubNoLocal	false	Set whether to inhibit the delivery of messages published by its own connection
selector	null	Sets the JMS Selector which is an SQL 92 predicate used to apply to messages to filter them at the message broker. You may have to encode special characters such as = as %3D
receiveTimeout	none	The timeout when receiving messages
recoveryInterval	none	The recovery interval
replyTo	null	Provides an explicit reply to destination which overrides any incoming value of Message.getJMSReplyTo()
replyToTempDestinationAffinity	endpoint	defines the component created temporary replyTo destination sharing strategy. Possible values are: component, endpoint or producer. component = a single temp queue is shared among all producers for a given component instance. endpoint = a single temp queue is shared among all producers for a given endpoint instance. producer = a single temp queue is created per producer.
replyToDestinationSelectorName	null	Sets the JMS Selector using the fixed name to be used so you can filter out your own replies from the others, when using a shared queue (i.e. if you are not using a temporary reply queue).
replyToDeliveryPersistent	true	Is persistent delivery used by default for reply?
requestTimeout	20000	The timeout when sending messages
serverSessionFactory	null	@deprecated - will be removed in Camel 2.0. The JMS ServerSessionFactory if you wish to use ServerSessionFactory for consumption
subscriptionDurable	false	Enabled by default if you specify a durableSubscriberName and a clientId
taskExecutor	null	Allows you to specify a custom task executor for consuming messages
templateConnectionFactory	null	The JMS connection factory used for sending messages
timeToLive	null	Is a time to live specified when sending messages
transacted	false	If transacted mode will be used for sending/receiving messages using the InOnly Exchange Pattern. See section Enabling Transacted Consumption for more details.
transactedInOut	false	If transacted mode will be used when sending/receiving messages using the InOut Exchange Pattern. See section Enabling Transacted Consumption for more details.
transactionManager	null	The Spring transaction manager to use
transactionName	null	The name of the transaction to use
transactionTimeout	null	The timeout value of the transaction if using transacted mode
transferException	false	Camel 2.0: If enabled and you are using Request Reply messaging (InOut) and an Exchange failed on the consumer side then the caused Exception will be send back as response as a javax.jms.ObjectMessage. If the client is Camel then that returned Exception will be rethrown. This allows you to use Camel JMS as a bridge in your routing, e.g. using persistent queues to enable robust routing. Notice that if you also have transferExchange enabled then this option takes precedence. The exceptions caught is required to be serializable. The original caused Exception on the consumer side can be wrapped in an outer exception such as org.apache.camel.RuntimeCamelException when returned to the producer.
transferExchange	false	Camel 2.0: You can transfer the exchange over the wire instead of just the body and headers. The following fields is transferred: in body, out body, fault body, in headers, out headers, fault headers, exchange properties, exchange exception. This requires that the objects are Serializable. Camel will exclude any non serializable objects and log it at WARN level.
username	null	The username which is set for the connector factory
useMessageIDAsCorrelationID	false	Should JMSMessageID be used as JMSCorrelationID for InOut messages. Camel will by default use a GUID
useVersion102	false	Should the old JMS API be used

Message Mapping between JMS and Camel

Camel will automatically map messages between javax.jms.Message and org.apache.camel.Message.

When sending a JMS message Camel will convert the body to the following JMS message:

When receiving a JMS message Camel will convert the JMS message to the following body type:

Overriding or controlling the mapping

Available as of Camel 2.0

You can use the option jmsMessageType on the endpoint to force using a specific message type for all messages.
In the route below we will poll files from a folder and send them as javax.jms.TextMessage as we have forced the JMS producer endpoint to use Text messages.

from("file://inbox/order").to("jms:queue:order?jmsMessageType=Text");

You can also provide a per. message type as a header with the key CamelJmsMessageType.

from("file://inbox/order").setHeader("CamelJmsMessageType", JmsMessageType.Text).to("jms:queue:order");

The possible values is defined in an enum class org.apache.camel.jms.JmsMessageType.

Message format when sending

The exchange that is sent over the JMS wire must conform to the JMS Message spec.

For the exchange.in.header the following rules apply for the keys:

• Keys stating with JMS or JMSX is reserved.
• exchange.in.headers keys must be literals and all be valid Java identifiers. (do not use dots in the key name)
• In Camel 1.4 onwards Camel will automatically replace all dots with underscore for key names. And vice-versa when Camel consumes JMS messages.
• In Camel 2.0 onwards Camel will also replace all hyphens with the special token: _HYPHEN_. And vice-versa when Camel consumes JMS messages.
• See also option jmsKeyFormatStrategy introduced in Camel 2.0.

For the exchange.in.header the following rules apply for the values:

• The values must be primitives or their counter objects (such as Integer, Long, Character). String, CharSequence, Date, BigDecimal or BigInteger is all converted to their toString() representation. All other types is dropped.

Camel will log with category org.apache.camel.component.jms.JmsBinding at DEBUG level if it drops a given header value. Example:

2008-07-09 06:43:04,046 [main           ] DEBUG JmsBinding  
  - Ignoring non primitive header: order of class: org.apache.camel.component.jms.issues.DummyOrder with value: DummyOrder{orderId=333, itemId=4444, quantity=2}

Message format when receiving

Camel will add the following properties to the Exchange when it receives a message:

Camel will add the following JMS properties to the IN Message headers when it receives a JMS message:

As all the above information is standard JMS you can check the JMS documentation for further details.

About using Camel to send and receive messages and JMSReplyTo

The JMS component is complex and you have to pay attention how it works depending what you do. So this is a short summary of some of the areas/pitfalls to look for.

When Camel sends a message using its JMSProducer it will check the following conditions

• the message exchange pattern
• whether a JMSReplyTo was set in endpoint or message header
• whether any of these options have been set on the JMS endpoint: disableReplyTo, preserveMessageQos, explicitQosEnabled

All this can be a tad complex to understand and configured to support your use case.

JmsProducer

The JmsProducer behaves like this depending on configuration:

JmsConsumer

The JmsConsumer behaves like this depending on configuration:

So pay attention what the message exchange pattern is on your messages.

If you send a message to a JMS destination in the middle of your route you can specify the exchange pattern to use, see more at Request Reply.
This is useful if you want to send an inOnly message to a JMS topic:

from("activemq:queue:in")
   .to("bean:validateOrder")
   .to(ExchangePattern.InOnly, "activemq:topic:order")
   .to("bean:handleOrder");

Reuse endpoint and sending to different destinations computed at runtime

Available as of Camel 1.6.2/2.0
If you need to send messages to a lot of different JMS destinations it makes sense to reuse a jms endpoint and provide the real destination as a header with the message. This allows Camel to reuse the same endpoint but send to different destinations. This will greatly reduce the number of endpoints created, memory and thread usage.

You can provide the destination in the following headers:

Reusing endpoint but sending to a destination of choice

In the route below we send messages to a jms destination

from("file://inbox")
  .to("bean:validateFile")
  .to("activemq:queue:dummy");

Notice that we have used a dummy as queue name in the activemq destination. Its just something we need to provide.

Then in our validateFile bean we must set the header with the real destination

public void validateIt(Exchange exchange) {
   String id = ....
   exchange.getIn().setHeader("CamelJmsDestinationName", "order:" + id");
}

Then Camel will see this header and use it as destination instead of the one configured on the endpoint. So in this example Camel will use activemq:queue:order:2 assuming the id was 2.

Configuring different JMS providers

You can configure your JMS provider inside the Spring XML as follows...

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
</camelContext>

<bean id="activemq" class="org.apache.camel.component.jms.JmsComponent">
  <property name="connectionFactory">
    <bean class="org.apache.activemq.ActiveMQConnectionFactory">
      <property name="brokerURL" value="vm://localhost?broker.persistent=false"/>
    </bean>
  </property>
</bean>

Basically you can configure as many JMS component instances as you wish and give them a unique name via the id attribute. The above example configures an 'activemq' component. You could do the same to configure MQSeries, TibCo, BEA, Sonic etc.

Once you have a named JMS component you can then refer to endpoints within that component using URIs. For example for the component name'activemq' you can then refer to destinations as activemq:[queue:|topic:]destinationName. So you could use the same approach for working with all other JMS providers.

This works by the SpringCamelContext lazily fetching components from the spring context for the scheme name you use for Endpoint URIs and having the Component resolve the endpoint URIs.

Using JNDI to find the ConnectionFactory

If you are using a J2EE container you might want to lookup in JNDI to find your ConnectionFactory rather than use the usual <bean> mechanism in spring. You can do this using Spring's factory bean or the new Spring XML namespace. e.g.

<bean id="weblogic" class="org.apache.camel.component.jms.JmsComponent">
  <property name="connectionFactory" ref="myConnectionFactory"/>
</bean>

<jee:jndi-lookup id="myConnectionFactory" jndi-name="jms/connectionFactory"/>

Concurrent Consuming

A common requirement with JMS is to consume messages concurrently in many threads to achieve high throughput. As shown above you use the concurrentConsumers property above.

from("jms:SomeQueue?concurrentConsumers=20").
  bean(MyClass.class);

You can configure the properties on the JmsComponent if you wish or on specific endpoints via the URI or by configuring the JmsEndpoint directly.

Enabling Transacted Consumption

A common requirement is to consume from a queue in a transaction then process the message using the Camel route. To do this just ensure you set the following properties on the component/endpoint

• transacted = true
• transactionManager = a Transsaction Manager - typically the JmsTransactionManager

See also the Transactional Client EIP pattern for further details.

Transaction and Request Reply over JMS Note that when using Request Reply over JMS you cannot use a single transaction; as JMS will not send any messages until a commit is performed so the server side won't receive anything at all until the transaction commits. So with request/response you must commit a transaction after sending the first request and then use a separate transaction for receiving the response. Its for this reason that the transacted property only applies to InOnly message Exchange Pattern. If you still want to use transacted for InOut then you must use transactedInOut=true. To recap: if you have transacted=true, transactedInOut=false and are sending an InOut then the Exchange will not use transaction.

Using JMSReplyTo for late replies

Avaiable as of Camel 2.0

When using Camel as a JMS listener it will place a property on the Exchange with the ReplyTo javax.jms.Destination object in the key ReplyTo.
You can obtain this Destination as shown here:

Destination replyDestination = exchange.getProperty(JmsConstants.JMS_REPLY_DESTINATION, Destination.class);

And then later use it to send a reply using regular or Camel JMS.

// we need to pass in the JMS component, and in this sample we use ActiveMQ
    JmsEndpoint endpoint = JmsEndpoint.newInstance(replyDestination, activeMQComponent);
    // now we have the endpoint we can use regular Camel API to send a message to it
    template.sendBody(endpoint, "Here is the late reply.");

A different solution to sending it is to provide the replyDestination object in the same Exchange property when sending. Then Camel will pickup this property and use it for the real destination. This requires however that you send it to some dummy destination. Okay here goes:

// we pretend to send it to some non existing dummy queue
    template.send("activemq:queue:dummy, new Processor() {
        public void process(Exchange exchange) throws Exception {
            // and here we override the destination with the ReplyTo destination object so the message is sent to there instead of dummy
            exchange.setProperty(JmsConstants.JMS_DESTINATION, replyDestination);
            exchange.getIn().setBody("Here is the late reply.");
        }
    }

Using request timeout

In the sample below we send a Request Reply style message Exchange (we use the requestBody method = InOut) to the slow queue for further processing in Camel and we wait for a return reply.

// send a in-out with a timeout for 5 sec
Object out = template.requestBody("activemq:queue:slow?requestTimeout=5000", "Hello World");

Samples

JMS is used in many examples for other components as well. But we provide a few samples below to get started.

Receiving from JMS

In this sample we configure a route that receives JMS messages and routes the message to a POJO

from("jms:queue:foo").
     to("bean:myBusinessLogic");

You can of course use any of the EIP pattern so the route can be context based, such as filtering an order topic for the big spenders:

from("jms:topic:OrdersTopic").
  filter().method("myBean", "isGoldCustomer").
    to("jms:queue:BigSpendersQueue");

Sending to a JMS

In the sample below we poll a file folder and send the file content to a JMS topic. As we want the content of the file as a TextMessage instead of a BytesMessage we need to convert the body to a String.

from("file://orders").
  convertBodyTo(String.class).
  to("jms:topic:OrdersTopic");

Using Annotations

Camel also has annotations so you can use POJO Consuming and POJO Producing.

Spring DSL sample

The sample above are using the Java DSL. Camel also supports using Spring XML DSL. Here is the big spender sample using Spring DSL:

<route>
  <from uri="jms:topic:OrdersTopic"/>
  <filter>
    <method bean="myBean" method="isGoldCustomer"/>
    <to uri="jms:queue:BigSpendersQueue"/>
  </filter>
</route>

Other samples

JMS is used a lot in other samples for other components and EIP patterns as well in this Camel documentation. So feel free to browse the documentation. If you have good time then check out the this tutorial that uses JMS but focuses on how well Spring Remoting and Camel works together Tutorial-JmsRemoting.

Using JMS as a Dead Letter Queue storing Exchange

Available as of Camel 2.0
Normally when using JMS as transport in only transfers the body and headers as payload. If you want to use JMS with Dead Letter Channel using a JMS queue as the Dead Letter Queue then normally the caused Exception is not stored in the JMS message. You can therefore use the option transferExchange on the JMS dead letter queue to instruct Camel to store the entire Exchange in the queue as a javax.jms.ObjectMessage that holds a org.apache.camel.impl.DefaultExchangeHolder. This allows you to consume from the Dead Letter Queue and grap the caused exception using a Exchange property with the key Exchange.EXCEPTION_CAUGHT. The demo below illustrates this:

// setup error handler to use JMS as queue and store the entire Exchange
errorHandler(deadLetterChannel("jms:queue:dead?transferExchange=true"));

Then you can consume from the JMS queue and analyze the problem:

from("jms:queue:dead").to("bean:myErrorAnalyzer");

// and in our bean
String body = exchange.getIn().getBody();
Exception cause = exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class);
// the cause message is
String problem = cause.getMessage();

Using JMS as Dead Letter Channel storing error only

You can use JMS to store the cause error message or a custom body as you can set as you like. We use Message Translator EIP to do a transformation on the failed exchange before its moved to the JMS dead letter queue. The demo below illustrates this:

// we sent it to a seda dead queue first
errorHandler(deadLetterChannel("seda:dead"));

// and on the seda dead queue we can do the custom transformation before its sent to the JMS queue
from("seda:dead").transform(exceptionMessage()).to("jms:queue:dead");

Here we only store the original cause error message in the transform. You can however use any Expression to send whatever you like. Eg you can invoke a method on a Bean, use a custom processor or what else.

See Also

• Configuring Camel
• Component
• Endpoint
• Getting Started

• Transactional Client
• Bean Integration
• Tutorial-JmsRemoting
• JMSTemplate gotchas