This abstract class defines the service-provider interface for KeyFactory. A security provider must implement a concrete subclass of this class for each cryptographic algorithm it supports. Applications never need to use or subclass this class.

public abstract class KeyFactorySpi {
// Public Constructors
     public KeyFactorySpi( );  
// Protected Instance Methods
     protected abstract PrivateKey engineGeneratePrivate(java.security.spec.
        KeySpec keySpec) throws java.security.spec.InvalidKeySpecException;  
     protected abstract PublicKey engineGeneratePublic(java.security.spec.
        KeySpec keySpec) throws java.security.spec.InvalidKeySpecException;  
     protected abstract <T extends java.security.spec.KeySpec> 
        T engineGetKeySpec(Key key, Class<T> keySpec) 
        throws java.security.spec.InvalidKeySpecException;  
     protected abstract Key engineTranslateKey(Key key) 
        throws InvalidKeyException;  
}

Passed To

KeyFactory.KeyFactory( )