Page History

h2. SJMS Component

*Available as of Camel 2.11*

{note}
This component is under active development.
{note}

The SJMS Component is a JMS client for Camel based purely on the JMS API.  It will be released as part of Camel 2.11 with the following functionality:

* Queue and Topic Support (Durable & Non-Durable)
* InOnly & InOut Support
* Plugable Connection Resource Management
* Session, Consumer, & Producer Pooling & Caching Management
* Asynchronous Producer and Consumer Processing
* Internal JMS Transaction Support

{info:title=Why the S in SJMS}
S stands for Simple and Standard and Springless.  Also camel-jms was already taken. :)
{info}

Maven users will need to add the following dependency to their {{pom.xml}} for this component:
{code:xml}
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-sjms</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>
{code}

h3. URI format

{code}
sjms:[queue:|topic:]destinationName[?options]
{code}

Where {{destinationName}} is a JMS queue or topic name. By default, the {{destinationName}} is interpreted as a queue name. For example, to connect to the queue, {{FOO.BAR}} use:

{code}
sjms:FOO.BAR
{code}

You can include the optional {{queue:}} prefix, if you prefer:

{code}
sjms:queue:FOO.BAR
{code}

To connect to a topic, you _must_ include the {{topic:}} prefix. For example, to connect to the topic, {{Stocks.Prices}}, use:

{code}
sjms:topic:Stocks.Prices
{code}

You append query options to the URI using the following format, {{?option=value&option=value&...}}

h3. SjmsComponent Options and Configurations

Below is an example of how to configure the SjmsComponent with its required ConnectionFactory provider.  It will create a single connection by default and store it using the components internal pooling APIs to ensure that it is able to service Session creation requests in a thread safe manner.

{code}
SjmsComponent component = new SjmsComponent();
component.setConnectionFactory(new ActiveMQConnectionFactory("tcp://localhost:61616"));
getContext().addComponent("sjms", component);
{code}

For a SjmsComponent that is required to support a durable subscription, you can override the default ConnectionFactoryResource instance and set the *clientId* property.

{code}
ConnectionFactoryResource connectionResource = new ConnectionFactoryResource();
connectionResource.setConnectionFactory(new ActiveMQConnectionFactory("tcp://localhost:61616"));
connectionResource.setClientId("myclient-id");

SjmsComponent component = new SjmsComponent();
component.setConnectionResource(connectionResource);
component.setMaxConnections(1);
{code}

h3. Producers

The SjmsProducer Endpoint supports the following properties:

{div:class=confluenceTableSmall}
|| Option || Default Value || Description ||
| {{acknowledgementMode}} | {{AUTO_ACKNOWLEDGE}}  | The JMS acknowledgement name, which is one of: {{TRANSACTED}}, {{AUTO_ACKNOWLEDGE}} or {{DUPS_OK_ACKNOWLEDGE}}.  {{CLIENT_ACKNOWLEDGE}} is not supported at this time. |
| {{consumerCount}} | {{1}}  | *InOut only.* Defines the number of MessageListener instances that for response consumers. |
| {{exchangePattern}} | {{InOnly}}  | Sets the Producers message exchange pattern. |
| {{namedReplyTo}} | {{null}}  | *InOut only.* Specifies a named reply to destination for responses. |
| {{persistent}} | {{true}}  | Whether a message should be delivered with persistence enabled. |
| {{producerCount}} | {{1}}  | Defines the number of MessageProducer instances. |
| {{responseTimeOut}} | {{5000}}  | *InOut only.* Specifies the amount of time an InOut Producer will wait for its response. |
| {{synchronous}} | {{true}}  | Sets whether the Endpoint will use synchronous or asynchronous processing. |
| {{transacted}} | {{false}}  | If the endpoint should use a JMS Session transaction. |
| {{ttl}} | {{-1}}  | Disabled by default.  Sets the Message time to live header. |
{div}

h3. Consumers

The SjmsConsumer Endpoint supports the following properties:

{div:class=confluenceTableSmall}
|| Option || Default Value || Description ||
| {{acknowledgementMode}} | {{AUTO_ACKNOWLEDGE}}  | The JMS acknowledgement name, which is one of: {{TRANSACTED}}, {{CLIENTAUTO_ACKNOWLEDGE}}, or {{AUTODUPS_OK_ACKNOWLEDGE}},.  {{DUPSCLIENT_OK_ACKNOWLEDGE}} is not supported at this time. |
| {{consumerCount}} | {{1}}  | Defines the number of MessageListener instances. |
| {{durableSubscriptionId}} | {{null}} | Required for a durable subscriptions. |
| {{exchangePattern}} | {{InOnly}}  | Sets the Consumers message exchange pattern. |
| {{messageSelector}} | {{null}}  | Sets the message selector. |
| {{synchronous}} | {{true}}  | Sets whether the Endpoint will use synchronous or asynchronous processing. |
| {{transacted}} | {{false}}  | If the endpoint should use a JMS Session transaction. |
| {{ttl}} | {{-1}}  | Disabled by default.  Sets the Message time to live header. |
{div}

h3. Examples

h4. InOnly Producer - (Default)

The InOnly Producer is the default behavior of the SJMS Producer Endpoint.

{code}
from("direct:start")
    .to("sjms:queue:bar");
{code}

h4. InOut Producer

To enable InOut behavior append the {{exchangePattern}} attribute to the URI.  By default it will use a dedicated TemporaryQueue for each consumer.

{code}
from("direct:start")
    .to("sjms:queue:bar?exchangePattern=InOut");
{code}

You can specify a {{namedReplyTo}} though which can provide a better monitor point.

{code}
from("direct:start")
    .to("sjms:queue:bar?exchangePattern=InOut&namedReplyTo=my.reply.to.queue");
{code}

h3. Additional Notes

h4. Does Springless Mean I Can't Use Spring?

Not at all.  Below is an example of the SJMS component using the Spring DSL:

{code}
<route
    id="inout.named.reply.to.producer.route">
    <from
        uri="direct:invoke.named.reply.to.queue" />
    <to
        uri="sjms:queue:named.reply.to.queue?namedReplyTo=my.response.queue&amp;exchangePattern=InOut" />
</route>
{code}

Springless refers to moving away from the dependency on the Spring JMS API.  A new JMS client API is being developed from the ground up to power SJMS.

h4. Clustering

When using InOut with SJMS in a clustered environment you must either use TemporaryQueue destinations or use a unique named reply to destination per InOut producer endpoint.  Message correlation is handled by the endpoint, not with message selectors at the broker.  The InOut Producer Endpoint uses Java Concurrency Exchangers cached by the Message JMSCorrelationID.  This provides a nice performance increase while reducing the overhead on the broker since all the messages are consumed from the destination in the order they are produced by the interested consumer.

Currently the only correlation strategy is to use the JMSCorrelationId.  The InOut Consumer uses this strategy as well ensuring that all responses messages to the included JMSReplyTo destination also have the JMSCorrelationId copied from the request as well.

h3. Transaction Support {anchor:transactionCacheLevels}

There is currently no support the Camel Transaction Processor nor does it support the Java Transaction API (JTA).  Only internal JMS Session Transactions are supported at this time.