Add possibility to listen on a directory

[dr0i]

Add a parameter to DirReader.java that enables the Reader to listen without ending if a new file is put to the directory. If a new file comes in the file is read and passed on, just like the Reader works on files it finds in the directory right now.

Would be useful for e.g. https://github.com/hbz/rpb/ where at the moment a new Flux instance is loaded and executed, i.e. a Fix and all lookup-tables coming with it is loaded anew. This happens atm sometimes 5 times a minute. With the "directory-listener" option the Flux and Fix would also be loaded once.

[TobiasNx]

I am not sure if that is conceptionally possible since the transformation result is always written in the same output/file except if you are adding a batch-reset. Is the output file then usable for further processing in RPB?

[dr0i]

If that would be so: how is it overwriting prevented atm?

[TobiasNx]

Overwriting is by default. I think there is no way to do it, but introducing a new variable for the filename.

[dr0i]

but introducing a new variable for the filename.

So we will do this.
However, a bit offtopic:
So, as I wrote: there are sometimes multiple documents catalogued. I think that that can happen the same time by different people. What happens if, say, by coincidence, two records are catalogued nearly at the same time? But let us discuss this in the rpb repo - if my interpretation is correct and may result in the loss of documents.