How to using ByteToMessageDecoder correctly

[Daniel]

Hello, everyone,

     I have developed a project that using ByteToMessageCodec to handle sticky and unpacking TCP/IP message. Although it works , but I am confused about how to Netty Framework to judge whether a ByteBuf should be dropped or accumulated.

    For example, in line 38 and 75,  it should be accumulated to form a complete data, meanwhile, in line 46, it should be dropped, because it is a invalid package. I used the same way to code it "return".  I think it should be coded differently.

Thanks in advanced.