SFTP delegation example

[G U BHARATH CHANDRA]

I understand there is a sample of dynamic FTP.
But would be helpful to have a SFTP delegation sample for outbound adapter as well , using SFTP session caching and factory methods.

Thanks

[Artem Bilan]

Please, elaborate what is "SFTP delegation"?

By the way, if you have something in mind already, it is OK to raise a PR and we will review it shortly.

Thanks

[G U BHARATH CHANDRA]

Hi ,

By SFTP Delegation I mean invoking different session factories at runtime as mentioned in docs :
https://docs.spring.io/spring-integration/reference/html/sftp.html#sftp-dsf

I don't completely follow the docs, but I am working on the above scenario.

Thanks

[Artem Bilan]

OK. Got it! Yeah.. we indeed may consider to add some simple sample on the matter.
Meanwhile I don't think the "Dynamic FTP" is relevant somehow to the DelegatingSessionFactory.

On the other hand let's see first of all what is your struggle because I think the sample we can come up may not be so helpful for you.

As you see the DelegatingSessionFactory is based on the ThreadLocal. So, before using its current state in the flow, you should populate a key for desired delegate. The setThreadKey() and clearThreadKey() API is there for you.

You can look into https://github.com/spring-projects/spring-integration/blob/master/spring-integration-file/src/test/java/org/springframework/integration/file/remote/session/DelegatingSessionFactoryTests.java and its XML config: https://github.com/spring-projects/spring-integration/blob/master/spring-integration-file/src/test/java/org/springframework/integration/file/remote/session/delegating-session-factory-context.xml to see how it is used.

[G U BHARATH CHANDRA]

This is definitely gonna help me , thank u for the explanation , I see things more clearly now by going throught those links.

Will see what I can come up with.

Thanks.

[G U BHARATH CHANDRA]

Hi,

I currently have a working code for 2 SFTP configs but i am using 2 SFTP Outbound adapter and calling the appropriate channel based on the header, which I'm guessing is not the best practice...

But below is the XML config that i came up with using DelegatingSessionFactory but i do have 2 questions which I'm not able to figure out, would be really helpful if u could take a look at it.

Added Intent and Questions in the Comments in the gist below :

public gist

let me know if this isn't the right place to ask the question :) !!

Thanks

[Artem Bilan]

Sure!
Here is what I see in your code:

org.springframework.messaging.MessageHandlingException: Expression evaluation failed: @dsf.setThreadKey('ONE'); nested exception is org.springframework.expression.AccessException: Could not resolve bean reference against BeanFactory

That @dsf is a reference to a bean, but your one is this:

<bean id="delegatingSessionFactory"     class="org.springframework.integration.file.remote.session.DelegatingSessionFactory">

So, or rename this bean to dsf or use delegatingSessionFactory in those expressions instead.
See more info in Docs: https://docs.spring.io/spring-integration/reference/html/spel.html#spel

headers['factoryToUse'] - you need to be sure that you really set this header in advance - to one or another delegate key.

[G U BHARATH CHANDRA]

Woah !

Works like a charm !!

Not sure how I missed that ...Thank you very much @artembilan .

[Artem Bilan]

Great!

Closing as nothing to discuss any more