In the SunEC provider, some algorithms are implemented in Java, some others depends on native code (sunec library).  The implementation are mixed together, as make it hard to enable the pure Java implementation (for example KeyPairGenerator for different EC curves) if the native lib get removed (see JDK-8233954).

As EC is an essential algorithm for security connection, it would be nice the Java implemented curves could be used when customers could not use the native sunec library.