code: public static List<String> getAIALocations(X509Certificate cert) throws CertificateVerificationException {
  
          //Gets the DER-encoded OCTET string for the extension value for Authority information access points.
          byte[] aiaExtensionValue = cert.getExtensionValue(Extension.authorityInfoAccess.getId());
          if (aiaExtensionValue == null) {
              throw new CertificateVerificationException("Certificate doesn't have Authority Information Access points");
          }
          AuthorityInformationAccess authorityInformationAccess;
          ASN1InputStream asn1InputStream = null;
  
          try {
              DEROctetString oct = (DEROctetString) (new ASN1InputStream(new ByteArrayInputStream(aiaExtensionValue))
                      .readObject());
              asn1InputStream = new ASN1InputStream(oct.getOctets());
              authorityInformationAccess = AuthorityInformationAccess.getInstance(asn1InputStream.readObject());
          } catch (IOException e) {
              throw new CertificateVerificationException("Cannot read certificate to get OSCP urls", e);
          } finally {
              try {
                  if (asn1InputStream != null) {
                      asn1InputStream.close();
                  }
              } catch (IOException e) {
                  LOG.error("Cannot close ASN1InputStream", e);
              }
          }
  
          List<String> ocspUrlList = new ArrayList<>();
          AccessDescription[] accessDescriptions = authorityInformationAccess.getAccessDescriptions();
          for (AccessDescription accessDescription : accessDescriptions) {
  
              GeneralName gn = accessDescription.getAccessLocation();
              if (gn.getTagNo() == GeneralName.uniformResourceIdentifier) {
                  DERIA5String str = DERIA5String.getInstance(gn.getName());
                  String accessLocation = str.getString();
                  ocspUrlList.add(accessLocation);
              }
          }
          if (ocspUrlList.isEmpty()) {
              throw new CertificateVerificationException("Cannot get OCSP urls from certificate");
          }
          return ocspUrlList;
      }
docs: Authority Information Access (AIA) is a non-critical extension in an X509 Certificate. This contains the
  URL of the OCSP endpoint if one is available.
  
  @param cert is the certificate
  @return a lit of URLs in AIA extension of the certificate which will hopefully contain an OCSP endpoint.
  @throws CertificateVerificationException if any error occurs while retrieving authority access points from the
  certificate.