/**
  * Returns true if the nonce was generated usig <code>generateNonce</code> and if this is the
  * first check for that nonce.
  *
  * @param nonce the nonce to be checked
  * @return true if the nonce if the nonce was generated and this is the first check for that nonce
  */
 public boolean isValidNonce(String nonce) {
   Long time = nonceCache.remove(nonce);
   if (time == null) {
     return false;
   }
   return System.currentTimeMillis() - time < JiveConstants.MINUTE;
 }
 /**
  * Generates a new nonce. The <code>isValidNonce</code> method will return true when using nonces
  * generated by this method.
  *
  * @return a unique nonce
  */
 public String generateNonce() {
   String nonce = String.valueOf(nonceGenerator.nextLong());
   nonceCache.put(nonce, System.currentTimeMillis());
   return nonce;
 }