Java in a Nutshell, 5th Edition [Electronic resources]

This interface represents an RSA private key and provides direct access to the underlying key values. If you are working with a private key you know is an RSA key, you can cast the PrivateKey to an RSAPrivateKey.

public interface 
RSAPrivateKey  extends java.security.PrivateKeyRSAKey {
// Public Constants
5.0   public static final long 
serialVersionUID ;  =5187144804936595022
// Public Instance Methods
java.math.BigInteger 
getPrivateExponent ( );  
}

Implementations

RSAMultiPrimePrivateCrtKey, RSAPrivateCrtKey