public synchronized List < String > getExtendedKeyUsage ( ) throws CertificateParsingException { if ( readOnly && extKeyUsage != null ) { return extKeyUsage ; } else { ExtendedKeyUsageExtension ext = getExtendedKeyUsageExtension ( ) ; if ( ext == null ) { return null ; } extKeyUsage = Collections . unmodifiableList ( ext . getExtendedKeyUsage ( ) ) ; return extKeyUsage ; } }
This method are the overridden implementation of getExtendedKeyUsage method in X509Certificate in the Sun provider . It is better performance - wise since it returns cached values .