Java计算机到计算机的连接？

Question

Is it possible to have two computers socket-connect to each other without any server involved in Java? If so, how? I've only seen examples of server-client connections where the server is permanent.

For example:

1. 2 people, person A and person B, want to connect using this application
2. Person A runs application, clicks "host"
3. Application hands person A a code (IP+port?) and begins listening.
4. Person B clicks "join" and types in code.
5.  Person B's computer sees Person A's computer and they connect. Person A accepts connection.

I've never really understood this well. Please pardon me if this is a bad question.

Answer 1

In your scenario, person A's PC would be acting as the server and person B's would be acting as the client. Even if it is only temporary, the fact that A is listening for a connection means that it is acting as a server.

Answer 2

By definition, one side has to initiate the connection (ie issue the connect request). That means the other side has to have a server socket open to receive the connection. You could use the same code on both sides by making both implement client and server functionality, and assume the appropriate role (server or client) depending on which user initiates the connection.