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INT-1494 updated docs to replace 'scheduled-producer' with 'inbound-channel-adapter'

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Mark Fisher
2010-10-17 12:51:07 -04:00
parent d09dfd7c45
commit 466b3b4cd6
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src/docbkx/message-publishing.xml
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@@ -299,64 +299,70 @@ static class BankingOperationsImpl implements BankingOperations {
</section>
<section id="scheduled-producer">
<title>Producing and publishing messages based on schedule</title>
<title>Producing and publishing messages based on a scheduled trigger</title>
<para>
In the above sections we looked at the Message publishing feature of Spring Integration which constructs and publishes messages as by-products of Method invocations.
However you are still responsible to invoke the method.
With scheduling support added to Spring Framework 3.0 we've added another useful feature to Spring Integration - support for scheduled Message producers/publishers. Scheduling could be based on several triggers.
Currently we support <code>cron</code>, <code>fixed-rate</code>, <code>fixed-delay</code> as well as the custom triggers implemented by you.
However in that case, you are still responsible for invoking the method.
In Spring Integration 2.0 we've added another related useful feature: support for scheduled Message producers/publishers via the new "expression" attribute
on the 'inbound-channel-adapter' element. Scheduling could be based on several triggers, any one of which may be configured on the 'poller' sub-element.
Currently we support <code>cron</code>, <code>fixed-rate</code>, <code>fixed-delay</code> as well as any custom trigger implemented by you.
</para>
<para>
Support for scheduled producers/publishers is provided via <emphasis>&lt;scheduled-producer&gt;</emphasis> xml element.
Lets look at couple of examples:
As mentioned above, support for scheduled producers/publishers is provided via the <emphasis>&lt;inbound-channel-adapter&gt;</emphasis> xml element.
Let's look at couple of examples:
</para>
<para>
<programlisting language="xml"><![CDATA[<scheduled-producer id="fixedDelayProducer"
fixed-delay="1000"
payload-expression="'fixedDelayTest'"
channel="fixedDelayChannel"/>]]></programlisting>
<programlisting language="xml"><![CDATA[<inbound-channel-adapter id="fixedDelayProducer"
expression="'fixedDelayTest'"
channel="fixedDelayChannel">
<poller fixed-delay="1000"/>
</inbound-channel-adapter>]]></programlisting>
In the above example scheduled producer will be created which will construct the Message with payload being the result of the expression 
defined in <code>payload-expression</code> attribute. Such message will be created and sent every time after a delay specified in the <code>fixed-delay</code> attribute.
In the above example an inbound Channel Adapter will be created which will construct a Message with its payload being the result of the expression 
defined in the <code>expression</code> attribute. Such message will be created and sent every time after the delay specified by the <code>fixed-delay</code> attribute.
<programlisting language="xml"><![CDATA[<inbound-channel-adapter id="fixedRateProducer"
expression="'fixedRateTest'"
channel="fixedRateChannel">
<poller fixed-rate="1000"/>
</inbound-channel-adapter>]]></programlisting>
<programlisting language="xml"><![CDATA[<scheduled-producer id="fixedDelayProducer"
fixed-rate="1000"
payload-expression="'fixedDelayTest'"
channel="fixedDelayChannel"/>]]></programlisting>
This example is very similar to the previous one, except that we are using <code>fixed-rate</code> attribute which will allow us to send messages at the fixed rate.
This example is very similar to the previous one, except that we are using the <code>fixed-rate</code> attribute which will allow us to send messages at a fixed rate (measuring from the start time of each task).
<programlisting language="xml"><![CDATA[<scheduled-producer id="fixedDelayProducer"
cron="7 6 5 4 3 ?"
payload-expression="'fixedDelayTest'"
channel="fixedDelayChannel"/>]]></programlisting>
<programlisting language="xml"><![CDATA[<inbound-channel-adapter id="cronProducer"
expression="'cronTest'"
channel="cronChannel">
<poller cron="7 6 5 4 3 ?"/>
</inbound-channel-adapter>]]></programlisting>
This example demonstrates how you can apply Cron trigger specified by <code>cron</code> attribute.
This example demonstrates how you can apply a Cron trigger with a value specified in the <code>cron</code> attribute.
<programlisting language="xml"><![CDATA[<scheduled-producer id="headerExpressionsProducer" fixed-delay="99"
payload-expression="'headerExpressionsTest'"
<programlisting language="xml"><![CDATA[<inbound-channel-adapter id="headerExpressionsProducer"
expression="'headerExpressionsTest'"
channel="headerExpressionsChannel"
auto-startup="false">
<header name="foo" expression="6 * 7"/>
<header name="bar" value="x"/>
</scheduled-producer>]]></programlisting>
<poller fixed-delay="5000"/>
<header name="foo" expression="6 * 7"/>
<header name="bar" value="x"/>
</inbound-channel-adapter>]]></programlisting>
Here you can see that in a way very similar to Message publishing feature we are enriching a newly constructed Message with
extra Message headers which could take scalar values as well as Spring expressions.
Here you can see that in a way very similar to the Message publishing feature we are enriching a newly constructed Message with
extra Message headers which could take scalar values as well as the results of evaluating Spring expressions.
</para>
<para>
If you need to implement your own custom trigger you can use <code>trigger</code> attribute pointing to any spring configured
bean which implements <classname>org.springframework.scheduling.Trigger</classname> interface.
If you need to implement your own custom trigger you can use the <code>trigger</code> attribute to provide a reference to any spring configured
bean which implements the <classname>org.springframework.scheduling.Trigger</classname> interface.
<programlisting language="xml"><![CDATA[<scheduled-producer id="triggerRefProducer" trigger="customTrigger"
payload-expression="'triggerRefTest'" channel="triggerRefChannel"/>
<programlisting language="xml"><![CDATA[<inbound-channel-adapter id="triggerRefProducer"
expression="'triggerRefTest'" channel="triggerRefChannel">
<poller trigger="customTrigger"/>
</inbound-channel-adapter>
<beans:bean id="customTrigger" class="org.springframework.scheduling.support.PeriodicTrigger">
<beans:constructor-arg value="9999"/>
<beans:constructor-arg value="9999"/>
</beans:bean>]]></programlisting>
</para>