Exporting keys as ascii text

Question

How can you export a key as ascii text like an armored key in PGP? But not using PGP?

Answer 1

PGP's ascii-armored text uses Base64 encoding like this example taken from the java almanac:
http://javaalmanac.com/egs/java.security.cert/ExportCert.html
// This method writes a certificate to a file. If binary is false, the
    // certificate is base64 encoded.
    public static void export(java.security.cert.Certificate cert, File file, boolean binary) {
        try {
            // Get the encoded form which is suitable for exporting
            byte[] buf = cert.getEncoded();
            FileOutputStream os = new FileOutputStream(file);
            if (binary) {
                // Write in binary form
                os.write(buf);
            } else {
                // Write in text form
                Writer wr = new OutputStreamWriter(os, Charset.forName("UTF-8"));
                wr.write("-----BEGIN CERTIFICATE-----\n");
                wr.write(new sun.misc.BASE64Encoder().encode(buf));
                wr.write("\n-----END CERTIFICATE-----\n");
                wr.flush();
            os.close();
        } catch (CertificateEncodingException e) {
        } catch (IOException e) {
    }