add a decrypt case convert method

Author: pwnipc

src/main/java/CaesarShift.java

@@ -4,9 +4,10 @@ public class CaesarShift {
     private static final String ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; //Encapsulate and make the alphabet immutable
     private static int key = 25; //Initialize and encapsulate the shift key
     private static String encryptedMsg; //Create and encapsulate the message container
+    private static String decryptedMsg;
 
-    public String encrypt(String msg){
-        String upCased = msg.toUpperCase();
+    public String encrypt(String encryptMsg){
+        String upCased = encryptMsg.toUpperCase();
         char[] upCasedArrs = upCased.toCharArray();//split the string to a character array
         ArrayList<Character> encryptedChars = new ArrayList<Character>();
 
@@ -20,4 +21,8 @@ public String encrypt(String msg){
       return encryptedMsg;
     }
 
+    public String decrypt(String decryptMsg){
+        return decryptMsg.toUpperCase();
+    }
+
 }