Method decode

src/main/java/com/none/im/protocol/PacketCodec.java:78–106

(ByteBuf byteBuf)

    }

    public Packet decode(ByteBuf byteBuf) {
        //跳过magic number
        byteBuf.skipBytes(4);

        //跳过版本号
        byteBuf.skipBytes(1);

        //序列化算法标识
        byte serializeAlgorithm = byteBuf.readByte();

        //指令
        byte command = byteBuf.readByte();

        //数据包长度
        int length =byteBuf.readInt();

        byte[] bytes = new byte[length];
        byteBuf.readBytes(bytes);
        Class<? extends Packet> requestType =getRequestType(command);
        Serializer serializer = getSerializer(serializeAlgorithm);

        if(requestType != null && serializer != null) {
            //解码
            return serializer.deserialize(requestType, bytes);
        } else {
            System.out.println("指令或者序列化算法不存在！");
        }
        return null;
    }

    private Class<? extends Packet> getRequestType(byte command) {
        return packetTypeMap.get(command);