In Java or .NET, how would you create a server that listens to a specific port?

In Java or .NET, how would you create a server that listens to a specific port?

(Just a du开发者_运维知识库mmy server, I just want to get the high level idea.)

Suggest Sun's Learning Trail tutorial on writing a client and server for Java.

The key code you need (copied from the above link) is:

ServerSocket serverSocket = null;
try {
    serverSocket = new ServerSocket(4444);
} catch (IOException e) {
    System.out.println("Could not listen on port: 4444");
    System.exit(-1);
}

Not sure what you mean by "server", but yes, in .NET you can have a TcpListener listening on a specified port. I'm sure Java has something similar as well.

For Java, look up java.net.ServerSocket.

There is a tutorial here: http://java.sun.com/docs/books/tutorial/networking/sockets/clientServer.html.

Veery high level:

import java.io.*;
import java.net.*;
import java.util.Date;

public class Xyz {
    public static void main( String [] args ) throws IOException {
    ServerSocket serverSocket = new ServerSocket(8080);
     while( true ) {
          final Socket client = serverSocket.accept();
          Thread thread = new Thread( new Runnable() {
              public void run() {
                  handle( client ); // custom method 
              }
           });
           thread.start();
      }

    }
    public static void handle( Socket client ){
        try {

            PrintStream out = new PrintStream( client.getOutputStream() );
            out.println( new Date().toString() );
            out.close();
            client.close();

        } catch ( IOException e ){

        }
    }
}

That would open port 8080 and will accept connections. Each connection ( Socket ) will be attended in different threads by the handle method of this class ( which here just print the current date )

This is veeeeery high level. You'll need to add handling exception, concurrency, and of course you'll have to implement the handle method it self.