code: public static PublicKey stringToRSAPublicKey (String str)
      {
          try {
              BigInteger mod = new BigInteger(str.substring(0, str.indexOf(SPLIT)), 16);
              BigInteger exp = new BigInteger(str.substring(str.indexOf(SPLIT) + 1), 16);
              RSAPublicKeySpec keySpec = new RSAPublicKeySpec(mod, exp);
              KeyFactory kf = KeyFactory.getInstance("RSA");
              return kf.generatePublic(keySpec);
          } catch (NumberFormatException nfe) {
              log.warning("Failed to read key from string.", "str", str, nfe);
          } catch (GeneralSecurityException gse) {
              log.warning("Failed to read key from string.", "str", str, gse);
          }
          return null;
      }
docs: Creates a public key from the supplied string.