DotNetty 开源地址 https://github.com/Azure/DotNetty
1.国家部标808协议格式
标识位
采用 0x7e 表示，若校验码、消息头以及消息体中出现 0x7e，则要进行转义处理，转义
规则定义如下：
0x7e <————> 0x7d 后紧跟一个 0x02；
0x7d <————> 0x7d 后紧跟一个 0x01。
转义处理过程如下：
发送消息时：消息封装——>计算并填充校验码——>转义；
接收消息时：转义还原——>验证校验码——>解析消息。
示例：
发送一包内容为 0x30 0x7e 0x08 0x7d 0x55 的数据包，则经过封装如下：0x7e 0x30 7d 0x02 0x08 0x7d0x01 0x55 0x7
2.建立一个控制台程序
添加NuGet包
System.Text.Encoding.CodePages Microsoft.Extensions.Configuration.CommandLine Microsoft.Extensions.Configuration.EnvironmentVariables Microsoft.Extensions.Configuration.Json Microsoft.Extensions.Hosting Microsoft.Extensions.Logging.Console
3.dotnetty 通道配置,使用默认的DelimiterBasedFrameDecoder 看看是否能够实现分包
bootstrap.Option(ChannelOption.SoBacklog, 100).Handler(new LoggingHandler("SRV-LSTN"))
.ChildHandler(new ActionChannelInitializer<IChannel>(channel =>
{
IChannelPipeline pipeline = channel.Pipeline;
pipeline.AddLast(new LoggingHandler("SRV-CONN"));
pipeline.AddLast("framing-dec", new DelimiterBasedFrameDecoder(1024, false, LineDelimiter()));
pipeline.AddLast("ServerClientHandler", new DBServerClientHandler());
}));
public static IByteBuffer[] LineDelimiter()
{
return new[]
{
Unpooled.WrappedBuffer(new[] { (byte)0x7e, (byte)0x7e }),
Unpooled.WrappedBuffer(new[] { (byte)0x7e }),
};
}
用网络调试工具 发送数据 7E 81 00 00 03 01 82 40 55 60 49 00 00 00 01 04 38 7E ，发现服务器收到数据后，分包数据错误了（一包数据编程2包数据了，数据格式也不对）,
更改下分隔符代码，也出现一样的结果
public static IByteBuffer[] LineDelimiter()
{
return new[]
{
Unpooled.WrappedBuffer(new[] { (byte)0x7e }),
Unpooled.WrappedBuffer(new[] { (byte)0x7e }),
};
}
public static IByteBuffer[] LineDelimiter()
{
return new[]
{
Unpooled.WrappedBuffer(new[] { (byte)0x7e}),
};
}
4.使用ByteToMessageDecoder，代码如下
/// <summary>
///粘包处理 数据包 头和尾 标志 都包含分割 字符串
/// </summary>
public class BeiDouFrameDecoder : ByteToMessageDecoder
{
private int frameFlag = 0x7e;
private int manFrameLength;
private int minFrameLength;
private int delimiters = 2;
private IByteBuffer frameDelimiter;
/// <summary>
///
/// </summary>
/// <param name="frameFlag">数据包 标志</param>
/// <param name="maxFrameLength">数据包最大长度</param>
/// <param name="minFrameLength">数据包最小长度</param>
public BeiDouFrameDecoder(byte frameFlag, int maxFrameLength, int minFrameLength)
{
this.frameFlag = frameFlag;
this.manFrameLength = maxFrameLength;
this.minFrameLength = minFrameLength;
frameDelimiter = Unpooled.WrappedBuffer(new[] { frameFlag });
}
protected override void Decode(IChannelHandlerContext context, IByteBuffer input, List<object> output)
{
if (input.ReadableBytes <= minFrameLength)//还不够 最小帧的 数据
return;
int readLen = -1;
//标记
int OriginalReadIndex = input.ReaderIndex;
input.MarkReaderIndex();
if (frameFlag == input.GetByte(OriginalReadIndex))//找到头 第一个字节是头 不改变 ReaderIndex
{
input.SetReaderIndex(OriginalReadIndex + 1);
readLen = IndexOfEnd(input);
input.ResetReaderIndex();
if (readLen != -1)//没有找到尾
{
readLen += delimiters;
if (readLen > manFrameLength || readLen < minFrameLength)
{
input.SkipBytes(readLen);
}
else
{
IByteBuffer frame = input.ReadSlice(readLen);
frame.Retain();
output.Add(frame);
}
}
}
else
{
//找头
int readIndex = -1;
int seekReaderIndex = input.ReaderIndex + 1;
while (seekReaderIndex < input.WriterIndex)
{
if (frameFlag == input.GetByte(seekReaderIndex))//找到头部
{
readIndex = seekReaderIndex;
break;
}
seekReaderIndex++;
}
if (readIndex != -1)//找到头
{
if ((input.ReadableBytes - readIndex) < minFrameLength)//可以读取的 数据长度小于最小帧长度，说明还不够一包数据，等下一次再读取
{
input.ResetReaderIndex();//本次跳过 还原ReaderIndex
return;
}
input.SetReaderIndex(readIndex + 1);
readLen = IndexOfEnd(input);
if (readLen == -1)//没有找打 尾
{
input.SkipBytes(input.ReadableBytes);//本次跳过 后面的所有字节
}
else if (readLen > manFrameLength || readLen < minFrameLength)//找到帧 但是长度 小于 最小长度 是错误的帧 SkipBytes
{
input.SetReaderIndex(readIndex);
input.SkipBytes(readLen + delimiters);
}
else
{
input.SetReaderIndex(readIndex);
IByteBuffer frame = input.ReadSlice(readLen + delimiters);
frame.Retain();
output.Add(frame);
}
}
}
}
private int IndexOfEnd(IByteBuffer haystack)
{
for (int i = haystack.ReaderIndex; i < haystack.WriterIndex; i++)
{
if (haystack.GetByte(i) != frameFlag)
{
continue;
}
else
{
if (i == haystack.WriterIndex)
{
return -1;
}
}
//Found the needle from the haystack! 找到
return i - haystack.ReaderIndex;
}
return -1;
}
//private static int IndexOf(IByteBuffer haystack, IByteBuffer needle)
//{
// for (int i = haystack.ReaderIndex; i < haystack.WriterIndex; i++)
// {
// int haystackIndex = i;
// int needleIndex;
// for (needleIndex = 0; needleIndex < needle.Capacity; needleIndex++)
// {
// if (haystack.GetByte(haystackIndex) != needle.GetByte(needleIndex))
// {
// break;
// }
// else
// {
// haystackIndex++;
// if (haystackIndex == haystack.WriterIndex && needleIndex != needle.Capacity - 1)
// {
// return -1;
// }
// }
// }
// if (needleIndex == needle.Capacity)
// {
// // Found the needle from the haystack!
// return i - haystack.ReaderIndex;
// }
// }
// return -1;
//}
}
修改通道代码
bootstrap.Option(ChannelOption.SoBacklog, 100).Handler(new LoggingHandler("SRV-LSTN"))
.ChildHandler(new ActionChannelInitializer<IChannel>(channel =>
{
IChannelPipeline pipeline = channel.Pipeline;
pipeline.AddLast(new LoggingHandler("SRV-CONN"));
pipeline.AddLast("BeiDouFrameDecoder", new BeiDouFrameDecoder(0x7e, 2048, 12));
pipeline.AddLast("ServerClientHandler", new DBServerClientHandler());
}));
测试结果
水平有限，欢迎指正。谢谢。