code: protected void checkCRLDateValidity(X509CRL crl)
              throws CertPathValidatorException {
  
          Date now = new Date();
          boolean valid = crl.getThisUpdate().before(now) && ((crl.getNextUpdate() != null)
                  && (crl.getNextUpdate().after(now)));
          if (!valid) {
              throw new CertPathValidatorException("CRL issued by " + crl.getIssuerDN() + " has expired");
          }
      }
docs: /*
  Method to check the CRL validity for current time.
  
  @param crl
  @throws CertPathValidatorException