processFile

Category: Line-Based File Processing

Author: Stuart Reges

Book Chapter: 6.3

Problem: processFile

Write a static method processFile that takes a
   Scanner containing an input file as a parameter and that writes to
   System.out the same file with successive pairs of lines reversed in order.
   For example, if the input file contains the following text:

	Twas brillig and the slithy toves
	did gyre and gimble in the wabe.
	All mimsey were the borogroves,
	and the mome raths outgrabe.
	
	"Beware the Jabberwock, my son,
	the jaws that bite, the claws that catch,
	Beware the JubJub bird and shun
	the frumious bandersnatch."

   The program should print the first pair of lines in reverse order, then the
   second pair in reverse order, then the third pair in reverse order, and so
   on.  Thus, your method should produce the following output.

        did gyre and gimble in the wabe.
        Twas brillig and the slithy toves
        and the mome raths outgrabe.
        All mimsey were the borogroves,
        "Beware the Jabberwock, my son,
        
        Beware the JubJub bird and shun
        the jaws that bite, the claws that catch,
        the frumious bandersnatch."
        
   Notice that a line can be blank, as in the third pair.  Also notice that an
   input file can have an odd number of lines, as in the one above, in which
   case the last line is printed in its original position.  You may not make
   any assumptions about how many lines are in the Scanner.

   Write your solution to processFile below.