Java netty：抽象方法错误

问题描述

我最近在使用 netty 并在 NettyClient 和 NettyServer 之间发送数据包。不幸的是，我收到以下 java.lang.AbstractMethodError:

java.lang.AbstractMethodError: io.netty.channel.SimpleChannelInboundHandler.channelRead0(Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;)V
    at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
    at io.netty.handler.codec.BytetoMessageDecoder.fireChannelRead(BytetoMessageDecoder.java:326)
    at io.netty.handler.codec.BytetoMessageDecoder.fireChannelRead(BytetoMessageDecoder.java:313)
    at io.netty.handler.codec.BytetoMessageDecoder.callDecode(BytetoMessageDecoder.java:427)
    at io.netty.handler.codec.BytetoMessageDecoder.channelRead(BytetoMessageDecoder.java:281)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1422)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:931)
    at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:792)
    at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:502)
    at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:407)
    at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1050)
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    at java.lang.Thread.run(Thread.java:748)

当我的客户端从服务器接收数据包时会发生此错误。另一方面，everxthing 工作正常。我已经检查了两个程序的版本，他们使用了 5.0.0.Alpha2 版本上的 netty-all 工件。

我的客户端 SimpleChannelInboundHandler 的代码如下所示：

package de.jackboyplay.nettyclient.mechanics;

import de.jackboyplay.nettyclient.packets.Packet;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

public class NetworkHandler extends SimpleChannelInboundHandler<Packet>{


    @Override
    protected void messageReceived(ChannelHandlerContext chc,Packet packet) {
        packet.handle();
    }    

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx,Throwable cause) {      
        cause.printstacktrace();
        ctx.close();
    }

}

~JackboyPlay

解决方法

您应该使用 netty 4.1.x（使用最新版本）。您在此处看到的是类路径问题的结果。