You cannot generate key pair. You can generate private key or public key separately.

You cannot generate key pair.
You are allowed to generate public keys only.

Instantiate an object of SecureRandom class and call generateKeyPair() method

Create DSAKeyPairGenerator object passing parameters to the constructor and
invoke generateKeyPair() method to generate key pair

Create DSAParameterSpec objects and pass it to generateKeyPair() method of the KeyPairGenerator object

Create KeyPairGenerator and DSAParameterSpec objects,
use initialize() method to apply DSAParameterSpec and generateKeyPair() method to generate key pair