Updated Atbash to run faster

src/main/java/com/mattrixwv/CipherStreamJava/monoSubstitution/Atbash.java

@@ -5,6 +5,9 @@
 package com.mattrixwv.CipherStreamJava.monoSubstitution;
 
 
+import com.mattrixwv.CipherStreamJava.exceptions.InvalidInputException;
+
+
 public class Atbash{
 	private String inputString;		//Holds the string that needs encoded or decoded
 	private String outputString;	//The encoded/decoded string
@@ -20,12 +23,13 @@ public class Atbash{
 			//Decode if the letter is alphabetic
 			if(Character.isAlphabetic(currentChar)){
 				//Use either uppercase or lowercase for the base
-				char letterBase = 'a';
+				//(letterbase + 25 - (currentChar - letterBase))
 				if(Character.isUpperCase(currentChar)){
-					letterBase = 'A';
+					output.append((char)(155 - currentChar));
+				}
+				else{
+					output.append((char)(219 - currentChar));
 				}
-				//TODO: Test and see if there is a more efficient way to do this
-				output.append((char)(currentChar + 25 - (2 * (currentChar - letterBase))));
 			}
 			//Keep any punctuation/whitespace the way it is
 			else{
@@ -45,12 +49,13 @@ public class Atbash{
 			//Decode if the letter is alphabetic
 			if(Character.isAlphabetic(currentChar)){
 				//Use either uppercase or lowercase for the base
-				char letterBase = 'a';
+				//(letterbase + 25 - (currentChar - letterBase))
 				if(Character.isUpperCase(currentChar)){
-					letterBase = 'A';
+					output.append((char)(155 - currentChar));
+				}
+				else{
+					output.append((char)(219 - currentChar));
 				}
-				//TODO: Test and see if there is a more efficient way to do this
-				output.append((char)(currentChar + 25 - (2 * (currentChar - letterBase))));
 			}
 			//Keep any punctuatio/whitespace the way it is
 			else{
@@ -62,21 +67,30 @@ public class Atbash{
 		return outputString;
 	}
 	//Removes all invalid characters and sets inputString
-	private void setInputString(String input){
+	private void setInputString(String inputString) throws InvalidInputException{
+		if(inputString == null){
+			throw new NullPointerException("Input cannot be null");
+		}
+
 		if(!preserveCapitals){
 			//Convert all letters to lowercase
-			input = input.toLowerCase();
+			inputString = inputString.toLowerCase();
 		}
 		if(!preserveWhitespace){
 			//Remove all characters except capital letters
-			input = input.replaceAll("\\s+", "");
+			inputString = inputString.replaceAll("\\s+", "");
 		}
 		if(!preserveSymbols){
 			//Remove all non-alpha numeric and whitespace symbols
-			input = input.replaceAll("[^a-zA-Z0-9\\s]", "");
+			inputString = inputString.replaceAll("[^a-zA-Z\\s]", "");
 		}
+
 		//Save the string
-		inputString = input;
+		this.inputString = inputString;
+
+		if(this.inputString.isBlank()){
+			throw new InvalidInputException("Input must contain at least 1 character");
+		}
 	}
 
 
@@ -98,16 +112,16 @@ public class Atbash{
 	public String getOutputString(){
 		return outputString;
 	}
-	public String encode(String input){
+	public String encode(String inputString) throws InvalidInputException{
 		//Make sure everything is empty before you begin
 		reset();
-		setInputString(input);
+		setInputString(inputString);
 		return encode();
 	}
-	public String decode(String input){
+	public String decode(String inputString) throws InvalidInputException{
 		//Make sure everything is empty before you begin
 		reset();
-		setInputString(input);
+		setInputString(inputString);
 		return decode();
 	}
 	public void reset(){