diff --git a/assignments/src/MV3500Cohort2023MarchJune/Chojnacki/Assignment1Client.java b/assignments/src/MV3500Cohort2023MarchJune/Chojnacki/Assignment1Client.java new file mode 100644 index 0000000000000000000000000000000000000000..ce598f043e6cf5739dd387dea8f4c3b169c1cf8b --- /dev/null +++ b/assignments/src/MV3500Cohort2023MarchJune/Chojnacki/Assignment1Client.java @@ -0,0 +1,104 @@ +package MV3500Cohort2023MarchJune.Chojnacki; + +import java.io.*; +import java.net.*; + +/** + * This is Assignment 1 where I have modified the given code from TCPExample3Client + * -sleep time has been extended to give more time in between loops + * -Initial print line has been altered to reflect assingnment 1 + * -Loop only runs a finite number of times ,10. + * Before, we always used telnet (netcat) 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 the loop iterates. + * + * @author mcgredo + * @author brutzman@nps.edu + */ +public class Assignment1Client +{ + /** Default constructor */ + public Assignment1Client() + { + // default constructor + } + /** IPv6 String constant for localhost address, similarly IPv4 127.0.0.1 + * @see <a href="https://en.wikipedia.org/wiki/localhost">https://en.wikipedia.org/wiki/localhost</a> + * @see <a href="https://en.wikipedia.org/wiki/IPv6_address">https://en.wikipedia.org/wiki/IPv6_address</a> + */ + public final static String LOCALHOST = "0:0:0:0:0:0:0:1"; + + /** + * Program invocation, execution starts here + * @param args command-line arguments + */ + public static void main(String[] args) + { + // Local variables/fields + Socket socket = null; + InputStream is; + Reader isr; + BufferedReader br; + String serverMessage; + int clientLoopCount = 0; + int numberOfLoops = 10; + + try { + while (clientLoopCount < numberOfLoops) + { + clientLoopCount++; // increment at beginning of loop for reliability + System.out.println(Assignment1Client.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("======================Assignment1==========================="); + + System.out.print ("Client loop " + clientLoopCount + ": "); + System.out.println("We are connected to the server!"); + 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(800l); // slow things down, for example 500l (long) = 500 msec + + } // end while(true) // infinite loops are dangerous, be sure to kill this process! + } + catch (IOException | InterruptedException e) + { + System.err.println("Problem with " + TcpExample3Client.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(TcpExample3Client.class.getName() + " exit"); + } + } +}