base64 Encode

encode_decode.java

public String encode(String s, String key) {
        if (s != null)
            return base64Encode(xorWithKey(s.getBytes(), key.getBytes()));
        else
            return null;
    }

    public String decode(String s, String key) {
        if (s != null)
            return new String(xorWithKey(base64Decode(s), key.getBytes()));
        else
            return null;
    }

    private byte[] xorWithKey(byte[] a, byte[] key) {
        byte[] out = new byte[a.length];
        for (int i = 0; i < a.length; i++) {
            out[i] = (byte) (a[i] ^ key[i%key.length]);
        }
        return out;
    }

    private byte[] base64Decode(String s) {
        try {
            BASE64Decoder d = new BASE64Decoder();
            return d.decodeBuffer(s);
        } catch (IOException e) {throw new RuntimeException(e);}
    }

    private String base64Encode(byte[] bytes) {
        BASE64Encoder enc = new BASE64Encoder();
        return enc.encode(bytes).replaceAll("\\s", "");

    }