⟩ Why do I get unexpected characters from 8-bit character sets in WebLogic jDriver for Oracle?
If you are using an Oracle database with an 8-bit character set on Solaris, make sure you set NLS_LANG to the proper value on the client. If NLS_LANG is unset, it defaults to a 7-bit ASCII character set, and tries to map characters greater than ASCII 128 to a reasonable approximation (for example, á, à, â would all map to a). Other characters are mapped to a question mark (?).