diff --git a/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_TCPIP_Client.java b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_TCPIP_Client.java new file mode 100644 index 0000000000000000000000000000000000000000..304caafd10cf3e1dd48b66880e1dfbae1ca59b79 --- /dev/null +++ b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_TCPIP_Client.java @@ -0,0 +1,76 @@ +package MV3500Cohort2019JulySeptember.homework2.Knobeloch; + +import java.io.*; +import java.math.BigDecimal; +import java.net.*; + +/** + * 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 + */ +public class Knobeloch_TCPIP_Client { + + // 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) { + + // Local vars/fields + Socket socket; + InputStream is; + InputStreamReader isr; + BufferedReader br; + String serverMessage; + double n = 2; + + System.out.println("First approximation of PI: 4"); + + try { + while (true) { + System.out.println("\n------------------------------------------------------------------------------------\n"); + System.out.println("More precise :-) ?"); + System.out.println("Lets try one more term of the Gregory-Leibniz series!"); + System.out.printf("Terms now: %.0f", n); + + // 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("\nCalculating..."); + System.out.printf("\nPi with %.0f terms = %s", n, serverMessage); + // socket gets closed, either automatically/silently by this code (or possibly by the server) + n++; + + } // end while(true) + } catch (IOException e) { + System.err.println("Problem with Knobeloch_TCPIP_Client 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 { + + // program exit: tell somebody about that + System.out.println("\nclient exit"); + } + } +} diff --git a/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_TCPIP_Server.java b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_TCPIP_Server.java new file mode 100644 index 0000000000000000000000000000000000000000..ddb8936bfe9de6d37c3d931586e07cc05b217c4e --- /dev/null +++ b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_TCPIP_Server.java @@ -0,0 +1,78 @@ +package MV3500Cohort2019JulySeptember.homework2.Knobeloch; + +import java.io.*; +import java.math.BigDecimal; +import java.net.*; + +/** + * Very slightly more complex than example1, further modifying example2. The + * only thing this does differently is introduce a loop into the response, so + * you don't have to restart the program after one response. Also, it prints out + * the socket pair the server sees. Run the program via telnet several times and + * compare the socket pairs. + * + * telnet (nc) localhost 2317 + * + * If you're sophisticated you can contact the instructor's computer while + * running this program. + * + * telnet (nc) [ipNumberOfServerLaptop] 2317 + * + * and have the instructor display the socket pairs received. + * + * @author mcgredo + */ +public class Knobeloch_TCPIP_Server { + + public static void main(String[] args) throws InterruptedException { + try { + + // ServerSocket waits for a connection from a client. + // Notice that it is outside the loop; ServerSocket + // needs to be made only once. + System.out.println("Knobeloch_TCPIP_Server has started..."); // it helps debugging to put this on console first + + ServerSocket serverSocket = new ServerSocket(2317); + OutputStream os; + PrintStream ps; + + double n = 2; + double nominator = 4; + BigDecimal apprxPi = new BigDecimal("4.0"); + + // Server is up and waiting (i.e. "blocked" or paused) + // Loop, infinitely, waiting for client connections. + // Stop the program somewhere else. + while (true) { + + // block until connected to a client + try (Socket clientConnection = serverSocket.accept()) { + // Now hook everything up (i.e. set up the streams), Java style: + os = clientConnection.getOutputStream(); + ps = new PrintStream(os); + nominator = nominator * (-1); + + BigDecimal toAdd = new BigDecimal((nominator / (n + (n-1)) ) ); + apprxPi = apprxPi.add(toAdd); + + ps.println("" + apprxPi ); // this gets sent back to client! + + // Notice the use of flush() and try w/ resources. Without + // the try w/ resources the Socket object may stay open for + // a while after the client has stopped needing this + // connection. try w/ resources explicitly ends the connection. + ps.flush(); + // like it or not, you're outta here! + n++; + } + } + } catch (IOException e) { + System.err.println("Problem with Knobeloch_TCPIP_Server networking: " + 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!"); + } + } + } +} diff --git a/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_UML.pdf b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_UML.pdf new file mode 100644 index 0000000000000000000000000000000000000000..a5edd580dcada679167f4a5e7fe2e054cefb6388 Binary files /dev/null and b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_UML.pdf differ diff --git a/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_UML.pptx b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_UML.pptx new file mode 100644 index 0000000000000000000000000000000000000000..4bae29f300196e1e02106c8092526a7a4ff4f357 Binary files /dev/null and b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Knobeloch/Knobeloch_UML.pptx differ