package TcpExamples; import java.io.*; import java.net.*; /** * Before, we always used telnet to connect to the server. Here we are now * writing our own program to do the connection. * * As you will see, when we run this after we start the server we will see the * same string telnet printed, sent by the server. The output at the server will * show different socket pairs for each time we ran it. * * @author mcgredo */ public class TcpExample3Client { // IPv6 String constant for localhost address, similarly IPv4 127.0.0.1 public final static String LOCALHOST = "0:0:0:0:0:0:0:1"; public static void main(String[] args) { try { while (true) { System.out.println("TcpExample3Client creating socket..."); // We request an IP to connect to ("localhost") and // port number at that IP (2317). This establishes // a connection to that IP in the form of the Socket // object; the server uses a ServerSocket to wait for // connections. Socket socket = new Socket(LOCALHOST, 2317); // locohost? // Now hook everything up (i.e. set up the streams), Java style: InputStream is = socket.getInputStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader br = new BufferedReader(isr); // Read the single line written by the server. We'd // do things a bit differently if many lines to be read // from the server, instead of one only. String serverMessage = br.readLine(); System.out.println("=================================================="); System.out.println("Now we're talking!"); System.out.println("The message the server sent was " + serverMessage); // socket gets closed, either automatically/silently this code (or possibly by server) } // end while(true) } catch (IOException e) { System.out.println("Problem with client: "); // describe what is happening System.out.println(e); // Provide more helpful information to user if exception occurs due to running twice at one time if (e instanceof java.net.BindException) System.out.println("*** Be sure to stop any other running instances of this program!"); } // program exit: tell somebody about that System.out.println("client exit"); } }