New to Java

Hello,
Please help me, I want to decode a file (coded in BCD) to a readable format (ascii)?
Deatailed information of the coded file:
Data Representation
Data representation: Binary, Binary Coded Decimal (BCD), International Standards Organization (ISO) and Telephony BCD (TBCD) characters

Numeral presentation: Left-adjusted with trailing #F (where required)

Text presentation: Left-adjusted with trailing spaces (where required)

Filler: Spaces for ISO characters and #F for BCD numbers and TBCD string

Thanks ahead!