code: public static boolean encodeToFile(byte[] dataToEncode, String filename) {
          boolean success = false;
          Base64.OutputStream bos = null;
          try {
              bos = new Base64.OutputStream(
                      new java.io.FileOutputStream(filename), Base64.ENCODE);
              bos.write(dataToEncode);
              success = true;
          }   // end try
          catch (java.io.IOException e) {
  
              success = false;
          }   // end catch: IOException
          finally {
              try {
                  if (bos != null) bos.close();
              } catch (Exception e) {
              }
          }   // end finally
  
          return success;
      }
docs: Convenience method for encoding data to a file.
  
  @param dataToEncode byte array of data to encode in base64 form
  @param filename     Filename for saving encoded data
  @return <tt>true</tt> if successful, <tt>false</tt> otherwise
  @since 2.1