@SuppressWarnings("unchecked")
    private static Constructor findNoArgConstructor(String className)
            throws ClassNotFoundException, InstantiationException {
        Class clazz = Class.forName(className);
        Constructor result;
        try {
            result = clazz.getDeclaredConstructor();
        } catch (NoSuchMethodException e) {
            throw new InstantiationException(
                    "Loading requires a no-arg constructor, but class "
                    + className + " lacks one.");
        }

        return result;
    }
Use reflection to gain access to the no-arg constructor of the named
class.

@return the pre-existing constructor (not null)
jme3-core/src/main/java/com/jme3/export/SavableClassUtil.java