Can there be worthwhile library for reading through / writing DBF files in java or other language ?

You may give this library an attempt:

http://dans-dbf-lib.sourceforge.net/

It's free (GPL) and pure Java.

It's very easy to get at via OleDB provider, for example via .Internet, Visual Foxpro would clearly have the ability to see clearly natively.

A fast google for dbase and jdbc cut back numerous links to have an xbase jdbc driver known as StelsDBF. Can't say I have tried on the extender or know greater than a quick google, but that might be my Java answer.

An alternate Java solution is always to setup an ODBC databases for dbase after which make use of the JdbcOdbc bridge

I have used the JDBC driver from HXTT. It's type-4 (pure java) and labored well. My knowledge about the JdbcOdbc bridge for the similar task was quite poor but that could have transformed in more recent releases. HXTT's driver is really a commercial product.

"every other language"? as with Python, maybe?

in Python I am using that one: dbfpy. (to not be mistaken with pydbf.)
very functional indeed.