CaesarCipher

class CaesarCipher {
    private final String ALPHABET = "abcdefghijklmnopqrstuvwxyz";
    public static void main(String args[])
    {
        String plainText = "ScannerWillBeBetter";
        int shiftKey=4;

        CaesarCipher cc = new CaesarCipher();

        String cipherText = cc.encrypt(plainText,shiftKey);
        System.out.println("Your Plain  Text :" + plainText);
        System.out.println("Your Cipher Text :" + cipherText);

        String cPlainText = cc.decrypt(cipherText,shiftKey);
        System.out.println("Your Plain Text  :" + cPlainText);
    }

    public String encrypt(String plainText,int shiftKey)
    {
        plainText = plainText.toLowerCase();
        String cipherText="";
        for(int i=0;i<plainText.length();i++)
        {
            int charPosition = ALPHABET.indexOf(plainText.charAt(i));
            int keyVal = (shiftKey+charPosition)%26;
            char replaceVal = this.ALPHABET.charAt(keyVal);
            cipherText += replaceVal;
        }
        return cipherText;
    }
    public String decrypt(String cipherText, int shiftKey)
    {
        cipherText = cipherText.toLowerCase();
        String plainText="";
        for(int i=0;i<cipherText.length();i++)
        {
            int charPosition = this.ALPHABET.indexOf(cipherText.charAt(i));
            int keyVal = (charPosition-shiftKey)%26;
            if(keyVal<0)
            {
                keyVal = this.ALPHABET.length() + keyVal;
            }
            char replaceVal = this.ALPHABET.charAt(keyVal);
            plainText += replaceVal;
        }
        return plainText;
    }
}