Can I change Netty pipeline by events? - websocket

Question

My app should do the next:
Send a POST request to server to get the token.
Connect to the websocket using this token in the headers while handshake.
Short question: To activate WebSocketClientProtocolHandler I have to fire event ctx.fireChannelActive() but from channelRead method because in this method I receive token from server . Is it correct place?
I implemented custom ChannelInboundHandlerAdapter and override:
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
super.channelActive(ctx);
authenticator.authenticate(ctx.channel()).addListener(new ChannelFutureListener() {
#Override
public void operationComplete(ChannelFuture channelFuture) throws Exception {
if (!channelFuture.isSuccess()) {
authPromise.tryFailure(channelFuture.cause());
ctx.fireExceptionCaught(new RuntimeException("Auth is failed."));
} else {
ctx.fireUserEventTriggered("Auth is successful");
}
}
});
}
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (!(msg instanceof FullHttpResponse)) {
ctx.fireChannelRead(msg);
}
FullHttpResponse response = (FullHttpResponse) msg;
try {
authenticator.finishAuthentication(ctx.channel(), response);
authPromise.trySuccess();
ctx.pipeline().remove(this);
ctx.fireChannelActive();
} finally {
response.release();
}
}
Authenticator class adds needed handlers, sends POST request and then it should parse response from server and change the pipeline.
public class Authenticator {
private final Logger LOGGER = LoggerFactory.getLogger(this.getClass());
private final ObjectMapper mapper = new ObjectMapper();
private final MessengerConfig messengerConfig;
public Authenticator(MessengerConfig messengerConfig) {
this.messengerConfig = messengerConfig;
}
public ChannelFuture authenticate(Channel channel) {
this.preCheck(channel);
return this.authenticate(channel, channel.newPromise());
}
private void preCheck(Channel channel) {
ChannelPipeline pipeline = channel.pipeline();
HttpClientCodec httpClientCodec = pipeline.get(HttpClientCodec.class);
if (httpClientCodec == null) {
LOGGER.warn("Pipeline does not contain HttpClientCodec.");
pipeline.addFirst(HttpClientCodec.class.getName(), new HttpClientCodec());
LOGGER.info("HttpClientCodec was added to pipeline.");
}
HttpObjectAggregator httpObjectAggregator = pipeline.get(HttpObjectAggregator.class);
if (httpObjectAggregator == null) {
LOGGER.warn("Pipeline does not contain HttpObjectAggregator.");
pipeline.addAfter(
HttpClientCodec.class.getName(),
HttpObjectAggregator.class.getName(),
new HttpObjectAggregator(8192)
);
LOGGER.info("HttpObjectAggregator was added to pipeline.");
}
}
private ChannelFuture authenticate(Channel channel, ChannelPromise promise) {
HttpRequest request = createAuthRequest();
try {
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
#Override
public void operationComplete(ChannelFuture channelFuture) throws Exception {
if (channelFuture.isSuccess()) {
promise.setSuccess();
} else {
promise.setFailure(new RuntimeException(""));
}
}
});
} catch (Exception e) {
LOGGER.error("Error", e);
}
return promise;
}
public void finishAuthentication(Channel channel, FullHttpResponse response) {
ByteBuf content = response.content();
AuthenticationData authenticationData = null;
try {
authenticationData = this.mapper.readValue(content.toString(CharsetUtil.UTF_8), AuthenticationData.class);
} catch (JsonProcessingException e) {
LOGGER.error("Can't parse authentication data.", e);
throw new RuntimeException((e));
}
LOGGER.info(Objects.toString(authenticationData));
DefaultWebSocketClientProtocolHandlerFactory factory = new DefaultWebSocketClientProtocolHandlerFactory();
WebSocketClientProtocolHandler handler = factory.getHandler(this.messengerConfig, authenticationData);
ChannelPipeline pipeline = channel.pipeline();
pipeline.addLast(WebSocketClientProtocolHandler.class.getName(), handler);
LOGGER.info("WebSocketClientProtocolHandler was added.");
pipeline.addLast(MessageHandler.class.getName(), new MessageHandler());
LOGGER.info("MessageHandler was added.");
}
So here I have two stages:
Auth stage with a pipeline:
io.netty.handler.codec.http.HttpClientCodec
io.netty.handler.codec.http.HttpObjectAggregator
AuthenticationHandler
2 Web-socket stage with a pipeline:
io.netty.handler.codec.http.HttpClientCodec
io.netty.handler.codec.http.HttpObjectAggregator
io.netty.handler.codec.http.websocketx.WebSocketClientProtocolHandshakeHandler
io.netty.handler.codec.http.websocketx.Utf8FrameValidator
io.netty.handler.codec.http.websocketx.WebSocketClientProtocolHandler
com.github.apsyvenko.client.messaging.MessageHandler
To activate second stage I have to fire event - ctx.fireChannelActive() but from channelRead.
As a result I got an exception:
18:19:37.055 [nioEventLoopGroup-2-1] WARN i.n.channel.DefaultChannelPipeline - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.net.SocketException: Connection reset
after hand-shake had started.