pls

KeywordCipher.java

import java.util.ArrayList;

/**
 * Created by Connor on 5/9/16.
 */
public class KeywordCipher extends Message {
    private String key;
    private ArrayList<Character> list;
    public char[] ogAlpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();

    public KeywordCipher(String s, String k) {
        message = s.toUpperCase();
        this.key = k.toUpperCase();
        list = new ArrayList<Character>();

        generateAlphabet(key);
    }

    void generateAlphabet(String key){
        ArrayList<Character> alphas = new ArrayList<Character>();
        for (char aBet : ogAlpha)
            alphas.add(aBet);

        for (int i = 0; i < key.length(); i++) {
            if (!list.contains(key.charAt(i)) &&
                    !(key.charAt(i) < 65 || key.charAt(i) > 90)){
                list.add(key.charAt(i));
                alphas.remove(alphas.indexOf(key.charAt(i)));
            }
        }

        char lastChar = list.get(list.size()-1);
        for (int i = 0; i < alphas.size(); i++) {
            if (alphas.get(i) < lastChar){
                alphas.add(alphas.remove(i));
                i--;
            }
            else break;
        }

        while (list.size() < 26)
            list.add(alphas.remove(0));
    }

    @Override
    public void encrypt() {
        if (isEncrypted||message.length()==0) return;
        isEncrypted = true;

        message = encryptHelper(message);
    }

    public String encryptHelper(String msg){
        if (msg.length() < 1) return msg;

        return (msg.charAt(0) < 65 || msg.charAt(0) > 90) ?
                msg.substring(0, 1) + encryptHelper(msg.substring(1)) :
                String.valueOf(list.get(msg.charAt(0)-65)) + encryptHelper(msg.substring(1));
    }

    @Override
    public void decrypt() {
        if (!isEncrypted) return;

        for (int i = 0; i < message.length(); i++) {
            message =  (message.charAt(i) < 65 || message.charAt(i) > 90)?
                    message: message.substring(0,i) + ogAlpha[list.indexOf(message.charAt(i))] + message.substring(i+1);
        }

        isEncrypted = false;
    }
}

Message.java

/**
 * Created by Connor on 5/3/16.
 */
public abstract class Message implements Encryptable {
    protected String message;
    protected boolean isEncrypted;

    public void setMessage(String s){
        message = s;
    }

    @Override
    public String getMessage() {
        return message;
    }

    @Override
    public boolean isEncrypted() {
        return isEncrypted;
    }
}

RailFenceCipher.java

/**
 * Created by Connor on 5/3/16.
 */
public class RailFenceCipher extends Message{
    public RailFenceCipher(String s) {
        message = s;
        isEncrypted = false;
    }

    @Override
    public void encrypt() {
        if (isEncrypted||message.length()==0) return;
        isEncrypted = true;

        message = encryptHelper(message)+encryptHelper(message.substring(1));
    }

    public String encryptHelper(String str){
        if (str.length() <= 1)return str;
        return str.charAt(0)+encryptHelper(str.substring(2));
    }

    @Override
    public void decrypt() {
        if (!isEncrypted) return;

        int mid = (int) Math.ceil(message.length()/2.0);
        String a = message.substring(0,mid),z = message.substring(mid);

        message = decryptHelper(a,z);
        isEncrypted = false;
    }

    public String decryptHelper(String a,String z){
        if (a.length() <= 1 && z.length() <= 1)return a+z;
        return ""+ a.charAt(0) + z.charAt(0) + decryptHelper(a.substring(1),z.substring(1));
    }
}

ShiftCipher.java

/**
 * Created by Connor on 5/9/16.
 */
public class ShiftCipher extends Message{
    private int shift;

    public ShiftCipher(String s, int i) {
        message = s.toUpperCase();
        if (i < 1 || i > 25)
            throw new IllegalArgumentException("Shift value must be between 1 and 25.");
        shift = i;
    }

    @Override
    public void encrypt() {
        if (isEncrypted)return;
        isEncrypted = true;

        message = encryptHelper(message);
    }

    public String encryptHelper(String str){
        if (str.length() < 1)return str;
        return (str.charAt(0) < 65 || str.charAt(0) > 90) ?
                str.substring(0, 1) + encryptHelper(str.substring(1)) :
                String.valueOf((char) ((int) str.charAt(0) + shift)) + encryptHelper(str.substring(1));
    }

    @Override
    public void decrypt() {
        if (!isEncrypted) return;

        isEncrypted = false;
        shift *= -1;

        encrypt();

        isEncrypted = false;
        shift *= -1;
    }
}