Advanced Configuration

Using transactions

By default, generic consumers and SOAP consumers do not wrap message exchanges in transactions. If there is a failure during the exchange, you have no guarantee that resending the request will not result in duplicating a task that has already been completed.

If your application requires message exchanges to be wrapped in a transaction, you can use the endpoint's transacted attribute to specify the type of transactions to use. Table 3.3 describes the possible values for the transacted attribute.

Table 3.3. Consumer Transaction Support

Value	Description
`none`	Specifies that message exchanges are not wrapped in a transaction. This is the default setting.
`jms`	Specifies that message exchanges are wrapped in local JMS transactions.
`xa`	Specifies that message exchanges will be wrapped in an externally managed XA transaction. You must also provide a transaction manager when using XA transactions.

	Important
	Only the default listener container can support XA transactions.

Using message selectors

If you want to configure your consumer to use a JMS message selector, you can set the optional messageSelector attribute. The value of the attribute is the string value of the selector. For more information on the syntax used to specify message selectors, see the JMS 1.1 specification.

Using durable subscriptions

If you want to configure your server to use durable subscriptions, you need to set values for two attributes. To indicate that the consumer uses a durable subscription you set the subscriptionDurable attribute to true. You specify the name used to register the durable subscription using the durableSubscriberName attribute.

Example 3.7 shows a configuration snipit for a consumer that registers for a durable subscription.

Example 3.7. Consumer using a Durable Subscription

<beans xmlns:jms="http://servicemix.apache.org/jms/1.0"
       ... >
  ...
  <jms:soap-consumer wsdl="classpath:widgets.wsdl"
                     destinationName="widgetQueue"
                     connectionFactory="#connectionFactory"
                     subscriptionDurable="true"
                     durableSubscriberName="widgetSubscriber" />
  ...
</beans>