Add custom file mapping support

[viniciusam]

Added support for custom file mappings on the java api/client. I think it's working, but need some improvements.

One thing I noticed is the ut_file_mapper use default values on the function declaration, and because of that, if I want to use default parameters when user pass null values, I need to:

• build different sql queries
• or get default values from database before calling the build_file_mappings

For now, custom mapping only works if you pass all parameters.

[jgebal]

Hi @viniciusam,
If we need a change on the mapper, to make it more useful for Java API, we definitely should do so.
Do you see what would be the best way to have it implemented in PLSQL?
Maybe it should be some kind of builder?

[jgebal]

Or maybe, ut_file_mapper should just have NULL defaults.
Inside the function if parameter is passed as null, then the code would assign defaults.
What do you think?
That way you could call it from Java passing null params and DB would take care of it.
I actually think it's a nice solution. Would you be able to implement it?

[viniciusam]

Yes, good solution. I can implement it.