keyFactory.generatePrivate(pkcs8KeySpec)

This line of code generates a private key object using the PKCS#8 encoded key specification provided by the pkcs8KeySpec variable.

The keyFactory is an instance of the java.security.KeyFactory class, which is responsible for generating keys from their specifications. In this case, the private key is generated using the PKCS#8 format, which is a widely used standard for encoding private keys.

The generatePrivate() method of the KeyFactory class takes the PKCS#8 encoded key specification as input and returns a private key object that can be used for cryptographic operations such as encryption and decryption.