Created autokey cipher

src/main/java/mattrixwv/CipherStreamJava/Autokey.java

@@ -0,0 +1,106 @@
+//CipherStreamJava/src/main/java/mattrixwv/CipherStreamJava/Autokey.java
+//Matthew Ellison
+// Created: 07-25-21
+//Modified: 12-30--21
+//This is the declaration of the Autokey class
+package mattrixwv.CipherStreamJava;
+
+
+public class Autokey extends Vigenere{
+	//Special rules for setting the strings for encoding
+	private void encodeSet(String key, String input) throws Exception{
+		//Set the input
+		setInputString(input);
+
+		StringBuilder newKey = new StringBuilder();
+		//Remove all unneccessary elements from the key
+		setKeyword(key);
+		newKey.append(keyword);
+		//Remove all unneccessary elements from the input
+		setKeyword(input);
+		newKey.append(getKeyword());
+
+		//Make sure the key is not any longer than the input
+		key = newKey.substring(0, getKeyword().length());
+
+		//Set the new keyword
+		setKeyword(key);
+		//Make sure to update the offset
+		offset.clear();
+		setOffset();
+	}
+	//Setting the strings for decoding
+	private void decodeSet(String key, String input) throws Exception{
+		//Remove all unneccessary elements from the key
+		setKeyword(key);
+		//Remove all unneccessary elements from the input
+		inputString = "";
+		setInputString(input);
+	}
+	//Decodes the inputString
+	protected String decode() throws Exception{
+		//Decode what the key will allow, add that to the key and continue
+		StringBuilder currentOutput = new StringBuilder();
+		StringBuilder fullOutput = new StringBuilder();
+
+		//Step through every character in the inputString and advance it the correct amount, according to offset
+		int offsetCnt = 0;
+		for(int letterCnt = 0;letterCnt < inputString.length();++letterCnt){
+			//If we have reached the end of the keyword add what we have to it and continue
+			if(offsetCnt == keyword.length()){
+				setKeyword(keyword + currentOutput.toString());
+				fullOutput.append(currentOutput);
+				currentOutput = new StringBuilder();
+			}
+
+			char letter = inputString.charAt(letterCnt);
+			if(Character.isUpperCase(letter)){
+				letter -= offset.get((offsetCnt++) % offset.size());
+				if(letter < 'A'){
+					letter += 26;
+				}
+				else if(letter > 'Z'){
+					letter -= 26;
+				}
+			}
+			else if(Character.isLowerCase(letter)){
+				letter -= offset.get((offsetCnt++) % offset.size());
+				if(letter < 'a'){
+					letter += 26;
+				}
+				else if(letter > 'z'){
+					letter -= 26;
+				}
+			}
+			currentOutput.append(letter);
+		}
+		//Empty the last character that were decoded
+		fullOutput.append(currentOutput);
+
+		//Save and return the results
+		outputString = fullOutput.toString();
+		return outputString;
+	}
+
+
+	//Constructor
+	public Autokey(){
+		super();
+	}
+	public Autokey(boolean leaveCapitals, boolean leaveWhitespace, boolean leaveSymbols){
+		super(leaveCapitals, leaveWhitespace, leaveSymbols);
+	}
+	//Encodes inputString using the Autokey cipher
+	public String encode(String key, String input) throws Exception{
+		reset();
+		encodeSet(key, input);
+		return encode();
+	}
+	//Decodes inputString using the Autokey cipher
+	public String decode(String key, String input) throws Exception{
+		reset();
+		setInputString(input);
+		decodeSet(key, input);
+		return decode();
+	}
+}

src/main/java/mattrixwv/CipherStreamJava/Vigenere.java

@@ -92,7 +92,7 @@ public class Vigenere{
 		return outputString;
 	}
 	//Decodes inputString and stores the result in outputString
-	protected String decode(){
+	protected String decode() throws Exception{
 		StringBuilder output = new StringBuilder();
 
 		//Step through every character in the inputString and advance it the correct amount, according to offset