Hi All I want to convert the string (taken as input from user) into a secretkey.I am coding in J2ME.The algorithm used is blowfish.
The Java cryptography APIs are not available in Java ME.
You'll need to download the Bouncy Castle lightweight cryptography API, which supports Java ME. You can then extract the classes you need from there. I found a code example here that should help you get started.
About charsets: Java ME does indeed support UTF-8, so that's always a safe bet. And a good idea, yes, although you'll see a lot of code that doesn't specify a charset.