Where communities thrive

  • Join over 1.5M+ people
  • Join over 100K+ communities
  • Free without limits
  • Create your own community
Repo info
    @hepin1989 邮箱?
    Hi, anybody knows how to get access to the ChanelId in java 11?
    Maven says following:
    [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project server: Compilation failure
    [ERROR] /Application.java:[138,109] io.netty.channel.Channel.id() in package io.netty.channel is not accessible
    [ERROR]   (package io.netty.channel is declared in the unnamed module, but module io.netty.channel does not read it)

    Hi! I'm trying to use the tc-native library to dynamically load the FIPS compliant OpenSSL library inside Finagle. When I make the call to


    I'm getting an unsatisfied link error

    java.lang.UnsatisfiedLinkError: io.netty.internal.tcnative.NativeStaticallyReferencedJniMethods.sslOpCipherServerPreference()I
        at io.netty.internal.tcnative.NativeStaticallyReferencedJniMethods.sslOpCipherServerPreference(Native Method)
        at io.netty.internal.tcnative.SSL.<clinit>(SSL.java:67)

    I'm currently running on a MacBook but the ultimate location for this is Linux. Any help on where to look to solve this is appreciated.


    Hi, can anybody help me. I am trying to provide a custom Logging handler to print request and response details.

    public class CustomLogger extends LoggingHandler {
        public CustomLogger(Class<?> clazz) {
        protected String format(ChannelHandlerContext ctx, String event, Object arg) {
            if (arg instanceof ByteBuf) {
                ByteBuf msg = (ByteBuf) arg;
                return decode(msg, msg.readerIndex(), msg.readableBytes(), defaultCharset());
            return super.format(ctx, event, arg);
        private String decode(ByteBuf src, int readerIndex, int len, Charset charset) {
            if (len != 0) {
                byte[] array;
                int offset;
                if (src.hasArray()) {
                    array = src.array();
                    offset = src.arrayOffset() + readerIndex;
                } else {
                    array = allocateUninitializedArray(max(len, 1024));
                    offset = 0;
                    src.getBytes(readerIndex, array, 0, len);
                return new String(array, offset, len, charset);
            return "";

    But this does not print response content correctly

    response headers are printed correctly, but response body is printed like this
    what could be the reason?
    i am on netty 4.1.38
    Ferdinand Jacobs
    And channelinboundhandleadapter is what you're looking for I think
    @fjacobs i think for logging Netty suggests to use LoggingHandler
    and for more configuration, provide a custom implementation of this class
    thats what I did
    but it is printing these gibberish characters
    Ferdinand Jacobs


    I am trying to provide a custom Logging handler to print request and response details.

    The class description says: A ChannelHandler that logs all EVENTS using a logging framework.
    Do you understand which event are you trying to print and what format it has?
    I would just start with this simple HTTP client example to print the request: https://netty.io/4.1/xref/io/netty/example/http/snoop/package-summary.html
    Then read and understand how the pipeline works https://netty.io/4.1/api/io/netty/channel/ChannelPipeline.html
    Then make a new inbound handler for the client to print the response and put it in the pipeline after the decoder handler.
    You will understand the order of the handlers and when events are send, then you can implement the LoggingHandler.

    @fjacobs thanks for providing your inputs, but I am using reactor-netty and following other examples to solve my logging usecase. Mostly I want to capture WRITE and READ events. i have created a sample, let me post that in Reactor channel.
    Navaneet Agarwal

    Hi! I am seeing a behavior that is related to what is mentioned in this post - https://stackoverflow.com/questions/13330937/play-framework-netty-does-not-release-socket.

    Basically, the number of outbound tcp connections keep growing. The post says that this was resolved by switching to tomcat.
    Anyone aware of this issue? (I’m using Webflux with reactor-netty)


    Hello, everyone,
    I have developed a project that using ByteToMessageCodec to handle sticky and unpacking TCP/IP message. Although it works , but I am confused about how to Netty Framework to judge whether a ByteBuf should be dropped or accumulated.

    For example, in line 38 and 75, it should be accumulated to form a complete data, meanwhile, in line 46, it should be dropped, because it is a invalid package. I used the same way to code it "return". I think it should be coded differently.
    Thanks in advanced.

    I have read Netty source, in line 454 of ByteToMessageDecoder. It check whether ByteBuf is read, if oldInputLength equals in.readableBytes(), then ByteBuf will be discarded.
    Maybe my question is stupid. Sorry to bother you.
    Hi, we are getting timeouts in our integration tests written with Spring WebTestClient that leverages Netty when going from Netty version 4.1.42 to 4.1.43 on an "old" version of WSL. It seems to be related to the netty-transport-native-epoll artifact because downgrading that to 4.1.42 solves the issue. Does this sound familiar to anyone ?
    Martin Furmanski
    When a leak has been detected is the underlying buffer returned to the system? If not, why not?
    Christopher Kane

    Hi 👋
    I have been trying, without success, to create a HTTP/2 client with prior knowledge.
    My current working client does an upgrade using the following channel handler.

    new HttpClientUpgradeHandler(
            new Http2ClientUpgradeCodec(http2ConnectionHandler),

    I have tried alot of things, but my initial attempt still seems like it should work. The handler I have tried using is:

    new Http2ConnectionHandlerBuilder()

    I can see an outbound settings from on both server and client, and thats where the communication ceases.
    The server is fine as I have used curl to verify it.
    If anyone has any information that would thoughts as to what might be wrong I am all ears. Thanks in advance.

    Omid Dehghan
    Is there any book about Netty other than "Netty in Action" ?
    Omid Dehghan
    Just to make it clear, any good resource will do.
    Enrico Olivelli
    hello !
    I am trying to use OCSP stapling with Boring SSL, it seems that it is not working (using a ssl client it does report that OSCPS info is not available).
    is there any to enable some kind of debug ?
    Enrico Olivelli
    enableOcsp (server side) seems to not have any effect
    both on Mac and on Linux
    Enrico Olivelli
    with a (Java) debugger I am able to check that SSLContext.enableOcsp(ctx, isClient()); is called in ReferenceCountedOpenSslContext (current Netty master), then we go into Native code
    I am using latest tcnative with boring ssl
    Enrico Olivelli
    Is there anyway to debug errors, while contacting the OCSP responder or errors in the configuration of the trust store ?
    Enrico Olivelli
    Hi Guys!
    I have one question How to setup one connection clinet in Netty framework?
    Daniel Anderson
    Easy! Uhm have you taken a look at the netty documentation? You have so many options, without knowing more about your needs it would be harder to point you further in a right direction as many codecs, exist.
    Henrique Borges
    Hi Guys! There is a MessageEvent alternative in Netty4?
    Is there anyone here like to join Taobao IM team, we are located in HangZhou.
    Yuvraj Agrawal

    I am Yuvraj Agrawal currently pursuing B.Tech in CS from Indian Institute of Technology. I am currently having a course in Computer Networks and am highly interested to learn more and contribute in this field.

    I am also looking forward to GSOC 2020 and wish to contribute to your organization. I am new to open source development and am currently going through the documentation of netty. Please, help me with some minor bugs or projects to learn your code efficiently.


    Dennis Campagna

    Hello everyone! I'm a student in Engineering of Computing Systems at Politecnico di Milano (Italy).
    I'm interested in the project "Add io_uring based transport", for this year GSoC. I used Java in university project and I'm currently ending my internship as an Embedded Software Engineer where I mostly code in C.

    On GitHub I don't see any "good-first-issue" or similar tags, and looks like someone is already working on all the "help-wanted" issues. Any advice on where to start? :)
    I'm currently going through the linked PDF and Netty docs, but then I'd like to start contributing.

    hello, i'm getting error io.netty.channel.unix.Errors$NativeIoException: readAddress(..) failed: Connection reset by peer...
    Ferdinand Jacobs
    Praveen Kumar
    Hello, my name is Praveen Kumar .
    I want to contribute to this organisation. Can anyone help me how can I do that
    Hi there, my name is Jim Xu, nice to join you guys :)
    Please share the source code of netty framework im with me. Thank you. I can cooperate with you in China
    @zzm6368217 you find it on github?
    Hi, I am Lay Patel. I am a junior(3rd year) majoring in computer Science with a minor in Security and Risk Analysis, and pursuing my bachelors's degree from The Pennsylvania State University. I am interested in working with with you as a part of GSoC. I have experience in network technology. In my networking class, I designed a network architecture for a society, in a team driven environment. I have experience in python, java , C and other object oriented programming languages. I am ready to learn any new technology skills. I am interested in "Implement native event loop telemetry " project. What are the further instructions for me?