spring boot 2: 如何启用tomcat的nio2协议（Http11Nio2Protocol）

@Slf4j
@Component
class AppTomcatConnectorCustomizer implements WebServerFactoryCustomizer {

    @Override
    public void customize(ConfigurableServletWebServerFactory factory) {
        ((TomcatServletWebServerFactory) factory).setProtocol("org.apache.coyote.http11.Http11Nio2Protocol");
        ((TomcatServletWebServerFactory) factory).addConnectorCustomizers(new TomcatConnectorCustomizer() {
            @Override
            public void customize(Connector connector) {
                ProtocolHandler protocol = connector.getProtocolHandler();

                log.info("Tomcat({})  -- MaxConnection:{};MaxThreads:{};MinSpareThreads:{}", //
                        protocol.getClass().getName(), //
                        ((AbstractHttp11Protocol) protocol).getMaxConnections(), //
                        ((AbstractHttp11Protocol) protocol).getMaxThreads(), //
                        ((AbstractHttp11Protocol) protocol).getMinSpareThreads());

            }
        });
    }
}