Create a program that decodes messages. The messages will be encoded using a Caesar cypher, with each letter being decoded by replacing it with the previous letter in the alphabet. (Supposedly, this was invented by Julius Caesar.) The message: J MPWF KBWB would be decoded as I LOVE JAVA. Here is a stub to get you started:

public class Problem21 { public static void main(String[] args) { System.out.println(decodeMessage("J MPWF KBWB")); // I LOVE JAVA System.out.println(decodeMessage("ABCDEFGHIJKLMNOPQRSTUVWXYZ")); // ZABCDEFGHIJKLMNOPQRSTUVWXY System.out.println(decodeMessage("J HPU UP UIJT QPJOU PO NZ PXO!")); // I GOT TO THIS POINT ON MY OWN! } public static String decodeMessage(String phrase) { // Your code here } }