Networking

Here is a super-simple reduction of the code you will see in the Networking lab.

Note there are two separate classes here. Both need to run separately, with the server being run first.

package com.example.client;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;

public class ClientClass {


       public static void main(String args[]) throws IOException {

              SocketChannel sc = SocketChannel.open();

              sc.connect(new InetSocketAddress("localhost",9999));

              ByteBuffer bb = ByteBuffer.allocate(1024);

              bb.put("Hello world".getBytes());

              bb.flip();

              sc.write(bb);

              sc.close();

       }

} 



package com.example.server;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;

public class ServerClass {

       public static void main(String args[]) 
       {

              try(ServerSocketChannel ss = ServerSocketChannel.open()){

              ss.bind(new InetSocketAddress("localhost", 9999));

              while(true) {

                     final SocketChannel sc = ss.accept();

                      Runnable handler= ()-> {                      

                                  ByteBuffer bb = ByteBuffer.allocate(1024);

                                  try {

                                         sc.read(bb);

                                  } catch (IOException e) {

                                         e.printStackTrace();

                                  }

                                  try {

                                         System.out.print("*********************");

                                         System.out.println(new String(bb.array(),"ASCII"));

                                  } catch (UnsupportedEncodingException e) {

                                         e.printStackTrace();

                                  }

                           

                     }; 

                     new Thread(handler).start();

              }

       } catch(IOException e) {

           e.printStackTrace();

       }

    }

}