package MV3500Cohort2021JulySeptember.homework2.Robinson; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.Reader; import java.net.Socket; /** * * @author mrobi */ public class RobinsonTCP3exClient { private final static String LOCALHOST = "0:0:0:0:0:0:0:1"; /** * Program invocation, execution starts here * @param args command-line arguments * @throws java.lang.InterruptedException for user exit */ public static void main(String[] args) throws InterruptedException { // Local variables/fields Socket socket = null; InputStream is; Reader isr; BufferedReader br; String serverMessage; int clientLoopCount = 0; int totalLoops = 25; try { while (clientLoopCount < totalLoops) { clientLoopCount++; // increment at beginning of loop for reliability System.out.println(RobinsonTCP3exClient.class.getName() + " 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 a Socket // object; the server uses a ServerSocket to wait for // connections. socket = new Socket(LOCALHOST, 2317); // locohost? // Now hook everything up (i.e. set up the streams), Java style: is = socket.getInputStream(); isr = new InputStreamReader(is); br = new BufferedReader(isr); // Read a single line written by the server. We'd // do things a bit differently if there were many lines to be read // from the server instead of one only. serverMessage = br.readLine(); System.out.println("====================RobinsonHW2=============================="); System.out.print ("Client loop " + clientLoopCount + ": "); System.out.println("now we're talking!"); System.out.println("The message the server sent was: '" + serverMessage + "'"); // socket gets closed, either automatically/silently by this code (or possibly by the server) Thread.sleep(500l); // slow things down, for example 500l (long) = 500 msec (1/2 second) } // end while(true) // infinite loops are dangerous, be sure to kill this process! } catch (IOException e) { System.err.println("Problem with " + RobinsonTCP3exClient.class.getName() + " networking:"); // describe what is happening System.err.println("Error: " + e); // Provide more helpful information to user if exception occurs due to running twice at one time if (e instanceof java.net.BindException) { System.err.println("*** Be sure to stop any other running instances of programs using this port!"); } } finally // occurs after any other activity when shutting down { try { if (socket != null) socket.close(); } catch (IOException e) {} // program exit: tell somebody about that happening. Likely cause: server drops connection. System.out.println(); System.out.println(RobinsonTCP3exClient.class.getName() + " exit"); } } }