I think you mean how do you write what's IN the object to a text file, right?
In this case you don't have to cast them to Strings, they are already Strings. If you mean a single step to return the instance variables as a single String, you could override the toString() method of X to put them all together in one String:
In X...
Or something like that depending on your needs.
Then you have a choice of whether you want to build a big String(delimited by newlines) and write it to the file all at once, or write once for each object in the Vector. Check out these links for writers:
BufferedWriter FileWriter PrintWriter HTH,
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