diff --git a/assignments/src/MV3500Cohort2019JulySeptember/homework2/Yurkovich/Yurkovich_Client.java b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Yurkovich/Yurkovich_Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..d8ddc4e355977902358b4988940fa4bb6ec1355b
--- /dev/null
+++ b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Yurkovich/Yurkovich_Client.java
@@ -0,0 +1,88 @@
+package MV3500Cohort2019JulySeptember.homework2.Yurkovich;
+
+import java.io.*;
+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 Yurkovich_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;
+ Integer count = 0;
+
+ OutputStream os;
+ PrintStream ps;
+
+
+ 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 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("==================================================");
+ System.out.println("Now we're talking!");
+ System.out.println("The message the server sent was: '" + serverMessage + "'");
+ System.out.println("This was the "+ count +" connection.");
+ count++;
+ // socket gets closed, either automatically/silently by this code (or possibly by the server)
+
+
+ // Now hook everything up (i.e. set up the streams), Java style:
+ os = socket.getOutputStream();
+ ps = new PrintStream(os);
+ ps.println("This message was produced by the YurkClient."); // this gets sent back to client!
+
+ ps.flush();
+
+
+
+ } // end while(true)
+ } catch (IOException e) {
+ System.err.println("Problem with TcpExample3ServerClient 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/Yurkovich/Yurkovich_Server.java b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Yurkovich/Yurkovich_Server.java
new file mode 100644
index 0000000000000000000000000000000000000000..068d94f59871d06c66068554b0fb54a773bf5b1c
--- /dev/null
+++ b/assignments/src/MV3500Cohort2019JulySeptember/homework2/Yurkovich/Yurkovich_Server.java
@@ -0,0 +1,108 @@
+package MV3500Cohort2019JulySeptember.homework2.Yurkovich;
+
+import java.io.*;
+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 Yurkovich_Server {
+
+ public static void main(String[] args) {
+ 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("TcpExample3Server has started..."); // it helps debugging to put this on console first
+
+ ServerSocket serverSocket = new ServerSocket(2317);
+ OutputStream os;
+ PrintStream ps;
+ InetAddress localAddress, remoteAddress;
+
+ InputStream is;
+ InputStreamReader isr;
+ BufferedReader br;
+ String clientMessage;
+ int localPort, remotePort;
+
+ // 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);
+ ps.println("This message was produced by the YurkServer."); // this gets sent back to client!
+
+ // Print some information locally about the Socket connection.
+ // This includes the port and IP numbers on both sides (the socket pair).
+ localAddress = clientConnection.getLocalAddress();
+ remoteAddress = clientConnection.getInetAddress();
+ localPort = clientConnection.getLocalPort();
+ remotePort = clientConnection.getPort();
+
+ // My socket pair connection looks like this, to localhost:
+ // Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 54876 ))
+ // Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 54881 ))
+
+ // Why is the first IP/port the same, while the second set has different ports?
+ System.out.println("TcpExample3Server socket pair: (( " + localAddress.toString() + ", " + localPort + " ), ( "
+ + remoteAddress.toString() + ", " + remotePort + " ))");
+
+ // 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.
+
+ // Now hook everything up (i.e. set up the streams), Java style:
+ is = clientConnection.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.
+ clientMessage = br.readLine();
+ System.out.println("==================================================");
+ System.out.println("Now we're talking!");
+ System.out.println("The message the server sent was: '" + clientMessage + "'");
+// System.out.println("This was the "+ count +" connection.");
+
+
+
+ ps.flush();
+ // like it or not, you're outta here!
+ }
+ }
+ } catch (IOException e) {
+ System.err.println("Problem with TcpExample3Server 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!");
+ }
+ }
+ }
+}