Spring Integration - Implementing File Locking

[Chandra_Sivaraman]

Hey all

Need your guidance and suggestions to implement File Locking the right way.

I have a directory that may receive multiple data files. There would be multiple threads to read and process the files. Once a file is processed, it has to be archived and the original file needs to be deleted. Since there are multiple threads involved, I am exploring the File Locking mechanism in SI.

Please find below my current configuration:

<bean id="filter" class="org.springframework.integration.file.filters.RegexPatternFileListFilter">
    <constructor-arg name="pattern" value="${fileName.regex}" />
</bean>
	
<bean id="locker" class="org.springframework.integration.file.locking.NioFileLocker" />

<!-- scan to process files from recently created ones to the oldest -->
<bean id="customDirectorySanner" class="com.spring.int.Sample.CustomDirectoryScanner">
    <property name="sortOrder" value="Desc" />
    <property name="locker" ref="locker" />
</bean>

<!-- File Polling Components (first) -->
<integration:service-activator
	input-channel="inputChannelOne" ref="customJobLauncher" 
	method="processFile" />

<file:inbound-channel-adapter id="first" channel="inputChannelOne"
	directory="file:${dir.home.input}" 
	filter="filter"
	scanner="customDirectorySanner">
	<integration:poller id="pollerOne" fixed-delay="${polling.interval}" max-messages-per-poll="5"/>
</file:inbound-channel-adapter>

<!-- File Polling Components (second) -->
<integration:service-activator
	input-channel="inputChannelSecond" ref="customJobLauncher" 
	method="processFile" />

<file:inbound-channel-adapter id="first" channel="inputChannelSecond"
	directory="file:${dir.home.input}" 
	filter="filter"
	scanner="customDirectorySanner">
	<integration:poller id="pollerSecond" fixed-delay="${polling.interval}" max-messages-per-poll="5"/>
</file:inbound-channel-adapter>

The custom directory scanner is being injected with a locker and it takes care of locking the file.
When and where shall I unlock it?
Do I need to pass the locker to the Service Activator and invoke unlock() on the file?

Appreciate your suggestions and recommendations.

Thanks.
Chandra