Java Code using Queue
Write a program that opens a text file and reads its contents
into a queue of characters, it should read character by character
(including space/line change) and enqueue characters into a queue
one by one. Dequeue characters, change their cases (upper case to
lower case, lower case to upper case) and save them into a new text
file (all the chars are in the same order as the original file, but
with different upper/lower case)
use...