为什么以下简单的Java代码使用来自commons.dbcp块的池连接？

I have written a simple Java code, which attempts to store files in an hsqldb database. All it does is reads the files from a certain directory and puts them in the DB. It is single threaded, but I am using pooled connections from the apache commons.dbcp in order to be able to cope with the multithreaded access later.I have written a simple Java code, which attemp