C# dotnetty 分包解决方案 客户端服务端的代码

以下是使用C# dotnetty实现分包解决方案的客户端和服务端示例代码：

### 服务端代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DotNetty.Buffers;
using DotNetty.Codecs;
using DotNetty.Common.Utilities;
using DotNetty.Transport.Channels;

namespace Server
{
    public class MessageDecoder : LengthFieldBasedFrameDecoder
    {
        public MessageDecoder() : base(ByteOrder.LittleEndian, 1024, 0, 4, 0, 4)
        {
        }

        protected override Object Decode(IChannelHandlerContext ctx, IByteBuffer input)
        {
            var buffer = (IByteBuffer)base.Decode(ctx, input);

            if (buffer == null)
            {
                return null;
            }

            var length = buffer.ReadInt();
            var body = buffer.ReadBytes(length);

            return new Request()
            {
                Length = length,
                Body = body
            };
        }
    }

    public class MessageEncoder : MessageToByteEncoder<Response>
    {
        protected override void Encode(IChannelHandlerContext context, Response message, IByteBuffer output)
        {
            output.WriteInt(message.Length);
            output.WriteBytes(message.Body);
        }
    }

    public class ServerHandler : SimpleChannelInboundHandler<Request>
    {
        protected override void ChannelRead0(IChannelHandlerContext ctx, Request request)
        {
            Console.WriteLine($"Received message of length {request.Length}: {Encoding.UTF8.GetString(request.Body)}");

            var response = new Response()
            {
                Length = request.Length,
                Body = request.Body
            };

            ctx.WriteAsync(response);
        }

        public override void ExceptionCaught(IChannelHandlerContext context, Exception exception)
        {
            Console.WriteLine($"Exception: {exception}");
            context.CloseAsync();
        }
    }

    public class Request
    {
        public int Length { get; set; }
        public byte[] Body { get; set; }
    }

    public class Response
    {
        public int Length { get; set; }
        public byte[] Body { get; set; }
    }
}

### 客户端代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DotNetty.Buffers;
using DotNetty.Codecs;
using DotNetty.Common.Utilities;
using DotNetty.Transport.Channels;

namespace Client
{
    public class MessageDecoder : LengthFieldBasedFrameDecoder
    {
        public MessageDecoder() : base(ByteOrder.LittleEndian, 1024, 0, 4, 0, 4)
        {
        }

        protected override Object Decode(IChannelHandlerContext ctx, IByteBuffer input)
        {
            var buffer = (IByteBuffer)base.Decode(ctx, input);

            if (buffer == null)
            {
                return null;
            }

            var length = buffer.ReadInt();
            var body = buffer.ReadBytes(length);

            return new Response()
            {
                Length = length,
                Body = body
            };
        }
    }

    public class MessageEncoder : MessageToByteEncoder<Request>
    {
        protected override void Encode(IChannelHandlerContext context, Request message, IByteBuffer output)
        {
            output.WriteInt(message.Length);
            output.WriteBytes(message.Body);
        }
    }

    public class ClientHandler : SimpleChannelInboundHandler<Response>
    {
        private readonly TaskCompletionSource<Response> _responsePromise;

        public ClientHandler(TaskCompletionSource<Response> responsePromise)
        {
            _responsePromise = responsePromise;
        }

        protected override void ChannelRead0(IChannelHandlerContext ctx, Response response)
        {
            Console.WriteLine($"Received message of length {response.Length}: {Encoding.UTF8.GetString(response.Body)}");

            _responsePromise.TrySetResult(response);
        }

        public override void ExceptionCaught(IChannelHandlerContext context, Exception exception)
        {
            Console.WriteLine($"Exception: {exception}");
            context.CloseAsync();
        }
    }

    public class Request
    {
        public int Length { get; set; }
        public byte[] Body { get; set; }
    }

    public class Response
    {
        public int Length { get; set; }
        public byte[] Body { get; set; }
    }
}