How to add scheduler and custome checks around camel file processing - file

Question

Before explaining my problem I would state here that I am completely new to camel file processing. I have a requirement to read the file from a directory do some processing and delete them. This was a very high level requirement and I am able to achieve this using camel. But now I've got some new requirements as stated below. Need help on that.
Create this application as a job and trigger it by reading another directory where some specific files would be dropped other wise it should kicked of by its own every 15-20 minutes.
Before triggering the actual application make sure that the directory has some specific number of files present (say 25 files)
If all files are present - execute a method to create a unique tracking ID for all these 25 files. If I have a unique ID how can I make it available through multiple routes?
As of now I have tried implementing routepolicy but since I have never used it earlier I need some guidance so that I can go ahead with this.

Answer 1

1. Separe your route logic from route triggering
<route id="TriggerFromFile">
<from uri="file:triggerFolder" />
<log message="Triggered from file" />
<to uri="direct:startLogic" />
<route>
<route id="TriggerFromTimer">
<from uri="timer:triggerTimer?period=15m" />
<log message="Triggered from timer" />
<to uri="direct:startLogic" />
</route>
<route id="Logic>
<from uri="direct:startLogic" />
<to uri="..." />
</route>
2. Count the number of files and use that as a filter
Define a bean that counts the number of files in the dir, set that number
as body and validate using a filter.
<route id="TriggerFromFile">
<from uri="file:triggerFolder" />
<log message="Triggered from file" />
<to uri="direct:countFile" />
<route>
<route id="TriggerFromTimer">
<from uri="timer:triggerTimer?period=15m" />
<log message="Triggered from timer" />
<to uri="direct:countFile" />
</route>
<route id="FileCount">
<from uri="direct:countFile" />
<to uri="bean:countFilesInDir" />
<log message="There are ${body} files the directory" />
<filter>
<simple>${body} >= 25</simple>
<to uri="direct:startLogic" />
</filter>
</route>
<route id="Logic">
<from uri="direct:startLogic" />
<to uri="..." />
</route>
3. Set a Header to your Exchange's message before sending it to other routes
When Camel sends an Exchange between routes, headers and properties are copied.
Calculate a unique id in some way (concatenate file names, md5 of content, file modification timestamp....) and set it in a Header.
An header can hold any java object.