nativeinterface.swift

@CContext(Headers.class)
public class NativeInterface {
    public static class Headers implements CContext.Directives {
        @Override
        public List<String> getHeaderFiles() {
            return Collections.unmodifiableList(
              Arrays.asList("header.h")
            )
        }
    }
    @CEntryPoint(name="Java_function_in_C")
    public static int callJvm(IsolateThread isolateThread, int a) {
        // call your actual method here
    }
}