Java 服务器/客户端中的编组和解组

Question

I have some questions on how to set up a server with marshalling and unmarshalling capabilities. I have been given code by my instructor to implement the marshalling and unmarshalling, as well as sending and receiving the data through TCP. Here is my code.

First , since I need to send/receive for both a server and client I assume I need to have the files (TCPSender.java, TCPReceiver.java, and WireFormatWidget.java - the marshalling/unmarshalling class) in the same source path as both the client and the server. Based upon the code, that seems as if that's all I need to do. I don't seem to have to create any packages. Does that look right?

Second , since my server/client(s) will be running a marshalling/unmarshalling class, I can output data via string, and then the WireformatWidget will translate it in between the console print-outs.

Last I'm not 100 percent sure on the value of sending via byte arrays, could someone give me a run-down of why this is useful? Also, perhaps send me to a their trusted source on learning about them? I am consulting Java docs at the moment, and it is helpful, but I would like something more specific to my application. Thank you!

Answer 1

I think you'll need a Widget to read/write between your client(s) and server.

I'd suggest using Externalizable if you want to control the marshalling / unmarshalling. There's also the marker interface Serializable if you want to let Java automatically control the marshalling / unmarshalling.

As for why you might need to convert the state of a Widget to a byte[] ; it's generally so you can write them to and/or read them from somewhere (like a disk, or a remote client). Basically, it is one mechanism to restore the state of an instance programatically. Other such mechanism involves generating human readable representation (eg XML and JSON ).

Finally, for better help faster, please include your code in your question. Making it a link to an off-site image makes it unlikely to be read.