How to close or reset a http2 stream in Spring boot with embedded Netty server application? - spring-boot

Question

Our application runs on Springboot with embedded Netty server(enabled http2). And it exposes services via Rest Apis.
On Rest Api call, we have a scenario where we wanted to ignore the http2 request without sending any response.
Our Environment:
Reactor version(s) used: reactor-netty-http : 1.0.16
JVM version (java -version): 17.0.1
springBootVersion= 2.7.4
Do we have any support from Netty Server to close a http2 stream(request) without response?
Here is my code:
GreetingController.java
public class GreetingController {
private final GreetingService greetingService;
public GreetingController(GreetingService greetingService) {
this.greetingService = greetingService;
}
#GetMapping("/{name}")
private Mono<String> greet(#PathVariable String name) {
return greetingService.greet(name);
} }
DiscardOutBoundHandler.java
public class DiscardOutBoundHandler extends ChannelOutboundHandlerAdapter {
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception { System.out.println("Outbound Handler name: " + ctx.channel().pipeline().names()); promise.channel().close(); }
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { System.out.print("exceptionCaught call"); cause.printStackTrace(); ctx.close(); } }
NettyWebServerFactoryPortCustomizer,java
public class NettyWebServerFactoryPortCustomizer implements WebServerFactoryCustomizer<NettyReactiveWebServerFactory> {
#Override
public void customize(NettyReactiveWebServerFactory serverFactory) {
Http2 h2 = new Http2();
serverFactory.setHttp2(h2);
serverFactory.addServerCustomizers(new PortCustomizer(8443));
serverFactory.addServerCustomizers(
httpServer -> httpServer.doOnChannelInit((connectionObserver, channel, remoteAddress) -> {
ChannelPipeline channelPipeline = channel.pipeline();
channelPipeline.addLast("encoder", new DiscardOutBoundHandler());
}));
}
private static class PortCustomizer implements NettyServerCustomizer {
private final int port;
private PortCustomizer(int port) {
this.port = port;
}
#Override
public HttpServer apply(HttpServer httpServer) {
return httpServer.port(port);
}
} }

Answer 1

What you are talking about is the problem of the HTTP protocol layer, which should be solved at the HTTP protocol layer, while ChannelOutboundHandler is located at the transport layer, and you cannot solve the problem here.
import reactor.core.publisher.Mono;
import reactor.netty.DisposableServer;
import reactor.netty.http.HttpProtocol;
import reactor.netty.http.server.HttpServer;
public class HttpServerTest {
public static void main(String[] args) {
DisposableServer server =
HttpServer.create()
.port(8080)
.protocol(HttpProtocol.H2C)
.route(routes ->
routes.get("/hello",
(request, response) -> response.sendString(Mono.just("Hello World!")))
.get("/ignore",
(request, response) -> response.then())
).bindNow();
server.onDispose()
.block();
}
}