我可以在单线程中使用两个套接字吗？

Question

I am having trouble developing a chat application including file sharing. It's a server and client based desktop application. I am able to develop chat and also file sharing individually.

Now I want merge two project and having problem. Is it possible to use multiple socket in single thread like main thread? Or do I have to use one for chatting and another for file sharing?

Answer 1

I think that is possible but in the same thread one operation with one socket have to wait all the operations from annother finish. if you want the two operations execute at the same time do it in different threads. Hope that helps :)

Answer 2

Yes it is possible for a single thread to use multiple sockets. See the Selector API.

The basic idea is that the code in your thread needs to know about all of the selectable channels (sockets, open files, etc) that it needs to read from or write to. It registers the channels with the selector. Then you make a select call which will (for example) block until one of the registered channels is ready; eg which socket has data that can be read now ... without blocking.

It is complicated, but rather than explaining it all here, I suggest that you read Baeldung's Introduction to the Java NIO Selector which includes an example.

But the bottom line is that using Selector will probably entail significant restructuring of your existing code. And if your code is using (for example) a 3rd-party library to do the I/O, then this approach probably won't work. Using multiple threads may well be a simpler option.