/** * Checks that a {@link BackendFactory} is registered for the given URI {@code scheme}. * * @param scheme the URI scheme identifying the factory * * @return {@code true} if a factory is registered for the {@code scheme} */ public boolean isRegistered(@Nullable String scheme) { if (isNull(scheme)) { return false; } if (!factories.containsKey(scheme)) { registerAll(); } return factories.containsKey(scheme); }