UdpCodecHandler.encode数据时必须写入UdpAttachment吗

[luca-666]

有个疑问：encode会写入UdpAttachment，但是接收方decode数据包时又不关心发送方写入的UdpAttachment，所以encode那里是不是去掉UdpAttachment？

zfoo/net/src/main/java/com/zfoo/net/handler/codec/udp/UdpCodecHandler.java

Line 69 in 5b49303

NetContext.getPacketService().write(byteBuf, out.getPacket(), out.getAttachment());

public class UdpCodecHandler extends MessageToMessageCodec<DatagramPacket, EncodedPacketInfo> {
    @Override
    protected void decode(ChannelHandlerContext channelHandlerContext, DatagramPacket datagramPacket, List<Object> list) {
        ...
        var packetInfo = NetContext.getPacketService().read(sliceByteBuf);
        var sender = datagramPacket.sender();
        packetInfo.setAttachment(UdpAttachment.valueOf(sender.getHostString(), sender.getPort()));
        list.add(packetInfo);
    }

    @Override
    protected void encode(ChannelHandlerContext channelHandlerContext, EncodedPacketInfo out, List<Object> list) {
        var byteBuf = channelHandlerContext.alloc().ioBuffer();
        var udpAttachment = (UdpAttachment) out.getAttachment();
        NetContext.getPacketService().write(byteBuf, out.getPacket(), out.getAttachment());
        list.add(new DatagramPacket(byteBuf, new InetSocketAddress(udpAttachment.getHost(), udpAttachment.getPort())));
    }
}

[jaysunxiao]

是可以的，欢迎提pr优化