jdbc inbound channel adapter for doing only a single query at runtime

[pgrimard]

Mark - yes I do plan to add more logic to this application. I'm still in the early stages of the app right now which involves fetching some initial data from one datasource to then process it and eventually insert it into a second datasource.

[Mark Fisher]

If you define a "taskScheduler" bean explicitly, you can set its 'waitForTasksToCompleteOnShutdown' property to TRUE. Then when the context tries to stop the scheduler, it should wait until the currently running task (your poller) completes.

[pgrimard]

Would I then reference that bean in the "task-executor" attribute of my poller?

[Mark Fisher]

No, that's not necessary, if the bean's name is "taskScheduler" it will automatically replace the default instance.

[pgrimard]

Maybe I'm doing something wrong. I've added the following taskScheduler bean to my config, but the app still seems to terminate before the poller is done.

	<beans:bean id="taskScheduler" class="org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler">
		<beans:property name="waitForTasksToCompleteOnShutdown" value="true"/>
	</beans:bean>

[pgrimard]

I believe I figured it out. Rather than calling stop() on my ApplicationContext, I need to call shutdown() on my TaskScheduler instance. So with my own Trigger implementation and my own "taskScheduler" bean defined with its "waitForTasksToCompleteOnShutdown" property set to true, this is my resulting class so far. It seems to work as expected. My inbound channel adapter runs the query once like I want, returning a Message who's payload is a List of rows. Is this the right approach?

@Component
public class Client {	
	private static ThreadPoolTaskScheduler taskScheduler;
	
	@Inject
	public void setTaskScheduler(ThreadPoolTaskScheduler taskScheduler) {
		Client.taskScheduler = taskScheduler;
	}
	
	public static void main(String[] args) {
		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("/META-INF/spring/applicationContext.xml", Client.class);
		taskScheduler.shutdown();
	}
}

Including my integration.xml for completeness:

	<int-jdbc:inbound-channel-adapter query="select * from tblData_OutboundTrace where datediff(d, MidnightStartDate, getdate()) = 1 and Extension != '' order by MidnightStartDate asc"
		channel="outboundTraceResults"
		data-source="pfDataSource">
		<poller trigger="runOnceTrigger"/>
	</int-jdbc:inbound-channel-adapter>
		
	<channel id="outboundTraceResults"/>
	
	<service-activator id="outboundTraceProcessor" input-channel="outboundTraceResults"
		ref="pfMessageHandler" method="processOutboundTraceResults"/>
	
	<beans:bean id="pfMessageHandler"
		class="com.myco.phones.trace.PrairieFyreTraceMessageHandler"/>
	
	<beans:bean id="runOnceTrigger"
		class="com.myco.scheduling.RunOnceTrigger"/>
	
	<beans:bean id="taskScheduler"
		class="org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler"
		p:waitForTasksToCompleteOnShutdown="true"/>