You don't have a String in UTF-8 format. It's possible that you have an array of bytes that represents a String encoded using UTF-8, but Strings are raw Unicode characters and do not have an encoding. Was there another question that caused you to ask that? Perhaps it would be easier to answer the real question.
Althoug your conversion sound a bit strange, because US-ASCII is a subset of UTF-8, hence, some of the characters that you will convert from UTF-8 to US-ASCII may not have any representation in US-ASCII, and the ones which does were already part of the UTF-8.
Originally posted by Paul Clapham: Perhaps it would be easier to answer the real question.
real problem is , as per my requirement, I was trying to retrive user data, including password from LDAP using java APIs. but password for known user is displayed in different format, after going through link