Netty 解码器编码器错误

Question

我有以下问题。每次当我使用相同的编码器和解码器从客户端向服务器发送数据包时，都会在服务器控制台中收到以下错误：

    io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(72) + length(8) exceeds writerIndex(77): UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeNoCleanerDirectByteBuf(ridx: 72, widx: 77, cap: 1024)
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:461)
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:267)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1294)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:911)
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
        at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131)
        at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
        at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IndexOutOfBoundsException: readerIndex(72) + length(8) exceeds writerIndex(77): UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeNoCleanerDirectByteBuf(ridx: 72, widx: 77, cap: 1024)
        at io.netty.buffer.AbstractByteBuf.checkReadableBytes0(AbstractByteBuf.java:1168)
        at io.netty.buffer.AbstractByteBuf.readLong(AbstractByteBuf.java:651)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:27)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at net.rinet.rnclo.network.encoding.PacketDecoder.decode(PacketDecoder.java:39)
        at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:491)
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:430)
        ... 16 more

我的来源是这样的：

编码器：

import net.rinet.rnclo.network.Packet;
import net.rinet.rnclo.network.PacketRegistry;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import lombok.AllArgsConstructor;
import lombok.NoArgsConstructor;

/**
 * JavaDoc this file!
 *
 * @author Pascal
 * @version 29.10.2017
 */
@AllArgsConstructor
@NoArgsConstructor
public class PacketEncoder extends MessageToByteEncoder<Packet> {
    private PacketRegistry packetRegistry;

    @Override
    protected void encode(ChannelHandlerContext ctx, Packet packet, ByteBuf output) throws Exception {
        long id = this.packetRegistry.getPacketIdByClass(packet.getClass());
        output.writeLong(id);
        packet.write(output);
    }
}

我的解码器看起来像这样：

package net.rinet.rnclo.network.encoding;

import net.rinet.rnclo.network.Packet;
import net.rinet.rnclo.network.PacketRegistry;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import lombok.AllArgsConstructor;
import lombok.NoArgsConstructor;

import java.util.List;

/**
 * JavaDoc this file!
 *
 * @author Pascal
 * @version 29.10.2017
 */
@AllArgsConstructor
@NoArgsConstructor
public class PacketDecoder extends ByteToMessageDecoder {
    private PacketRegistry packetRegistry;

    @Override
    public void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> outputList) throws Exception {
        if(byteBuf.isReadable(2)) {
            long id = byteBuf.readLong();

            if(packetRegistry.checkPacketId(id)) {
                Class<? extends Packet> packetClass = packetRegistry.getPacketClassById(id);
                Packet receivedPacket = packetClass.newInstance();
                try {
                    receivedPacket.read(byteBuf);
                } catch (Throwable t) {
                    t.printStackTrace();
                }
                outputList.add(receivedPacket);
            } else {
                decode(channelHandlerContext, byteBuf, outputList);
            }
        }
    }
}

我的数据包看起来像这样：https://hastebin.com/atirenevuw.java

每一个有用的答案我都非常高兴！ 帕斯卡

Answer 1

您正在检查是否可以读取 2 个字节，但随后您读取了 8 个字节。

改变这个

        if(byteBuf.isReadable(2)) {
            long id = byteBuf.readLong();

到

        if(byteBuf.isReadable(8)) {
            long id = byteBuf.readLong();