Add ascending / descending order in java code

Hi @diptangsu
I would like to contribute to this project by adding asc / desc order depending on the algorithm to java code

Start by locating the Java sorting implementations and review how each currently orders values. The issue does not name files, algorithms, or tests, so clarify which algorithms need ascending and descending behavior first; done should mean the agreed Java implementations produce the requested order and are verified accordingly.

Scritto dal modello di indicizzazione a partire dal testo della issue.