import java.io.*; import java.net.*;

public class echoclient {  public static void main(String[] args) throws IOException {   //Set up the socket, in and out variables  Socket echoSocket = null;  PrintWriter echoClientOutput = null;  BufferedReader echoClientInput = null;

//Localhost is the generic name of the computer that your echoserver is running on //Change port 4321 to the port that your server is connected to the code then connects the input and output

 try {
echoSocket = new Socket("localhost", 4321);  //Make the connection to the server socket    //Create the Output and Input  echoClientOutput = new PrintWriter(echoSocket.getOutputStream(), true); echoClientInput = new BufferedReader(new InputStreamReader(echoSocket.getInputStream()));  } catch (UnknownHostException e) {   System.err.println("Can't find host");   System.exit(1);  } catch (IOException e) {   System.err.println("Couldn't get I/O for the connection to: 4321.");   System.exit(1);  }    //Connect the user input BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));  String fromUser;  String fromServer;   //Type some input, press return and see what comes back  System.out.println("echoclient up and running");  while (true) {   fromUser = stdIn.readLine();  //Read from the user   if (fromUser != null) {    System.out.println("Client: " + fromUser);     echoClientOutput.println(fromUser); //Write to the server   }  fromServer = echoClientInput.readLine(); //Wait and read from the server  System.out.println("Server: " + fromServer);  }    } }