Improve the classes of Exercise 5.12 so that it is possible to vary the encryption algorithm. Which design pattern are you employing?

Exercise 5.12

Supply decorator classes Enc rypti ngWri ter and Dec rypti ngReade r that encrypt and decrypt the characters of the underlying reader or writer. Make sure that these classes are again readers and writers so that you can apply additional decorations. For the encryption, simply use the Caesar cipher, which shifts the alphabet by three characters (i.e., A becomes D, B becomes E, and so on).