How to get unique Bytes from a String ?

[FarhanBajwa]

Hi,

I want to get bytes from a string value( for Encryption/Decryption purposes ), i have used getBytes() method for that purpose, but every time i call getBytes() method, it returns a new bytes of array each time. I want a unique bytes of array for a particular string. How ?
Also i want to store that information (string or byte) in a file, and i want to get back this information in form of bytes.

Is there a way to get a unique bytes of array for a particular string, each time i use getBytes() or any other method ?

Thanks...

[JavaServlet]

Check the Cryptography Architecture API specifically the MessageDigest Class.