SimpleCrypt/Crypto/src/Main/ROT13.java

import java.util.Arrays;
import java.util.List;

public class ROT13  {
    private int rotate;
    private int encryptShift = 26;
    private boolean encrypt;

    public boolean isEncrypt() {
        return encrypt;
    }

    public void setEncrypt(boolean encrypt) {
        this.encrypt = encrypt;
    }

    ROT13(Character cs, Character cf) {
        rotate = (int)(cs) - (int)(cf);
    }

    ROT13() {
    }

    public int getRotate() {
        return rotate;
    }

    public String crypt(String text){
        return encrypt(text);
    }

    public String crypt(String text, int rotate) throws UnsupportedOperationException {
        List<String> textList = Arrays.asList(text.split(" "));
        StringBuilder builder = new StringBuilder();

        for (String s: textList) {
            char[] charArr = s.toCharArray();
            for (char c: charArr) {
                String strToAppend = isEncrypt() ? shiftCharEncrypt(c, rotate) : shiftCharDecrypt(c, rotate);
                builder.append(strToAppend);
            }
            builder.append(" ");
        }
        return builder.toString().trim();
    }

    public String encrypt(String text) {
        setEncrypt(true);
        return crypt(text, getRotate());
    }

    public String decrypt(String text) {
        setEncrypt(false);
        return crypt(text, getRotate() * -1);
    }

    public String shiftCharEncrypt(char c, int rotate){
        if (c > 64){
            return  ( (c > 96 && (c + rotate) > 96) || (c <= 96 && (c + rotate) > 64) ) ?
                    ( Character.toString( (char)(c + rotate) ) ) :
                    ( Character.toString( (char)(c + rotate + encryptShift) ) );
        } else {
            return Character.toString(c);
        }
    }

    public String shiftCharDecrypt(char c, int rotate){
        if (c > 64){
            return  ( (c + rotate > 122) || (c <= 90  && c + rotate > 90 ) ) ?
                    ( Character.toString( (char)(c + rotate + encryptShift * -1) ) ) :
                    ( Character.toString( (char)(c + rotate) ) );
        } else {
            return Character.toString(c);
        }
    }

    public static String rotate(String s, Character c) {
        int rotateBy = (int)(c) - (int)(s.charAt(0));
        char[] charArr = s.toCharArray();
        char[] returnChar = new char[charArr.length];

        int x = 0;
        for (int i = rotateBy; i < returnChar.length; i++) {
            returnChar[x] = (char)( (int)(charArr[i]));
            x++;
        }

        for (int i = 0; i < rotateBy; i++) {
            returnChar[x] = (char)( (int)(charArr[i]));
            x++;
        }
        return String.copyValueOf(returnChar);
    }

}