diff --git a/assignments/nbproject/project.properties b/assignments/nbproject/project.properties
index 930f0ea1079fc1c2cff7087a8703ee500046eefe..5f759ac245d09fcfc1c8f031ba8e87a489582810 100644
--- a/assignments/nbproject/project.properties
+++ b/assignments/nbproject/project.properties
@@ -70,8 +70,8 @@ javac.modulepath=
javac.processormodulepath=
javac.processorpath=\
${javac.classpath}
-javac.source=17
-javac.target=17
+javac.source=11
+javac.target=11
javac.test.classpath=\
${javac.classpath}:\
${build.classes.dir}
diff --git a/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample1Telnet.java b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample1Telnet.java
new file mode 100644
index 0000000000000000000000000000000000000000..3f45997a9ddebc1353cd8e16240a2f934634f3bf
--- /dev/null
+++ b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample1Telnet.java
@@ -0,0 +1,92 @@
+package MV3500Cohort2023MarchJune.homework1.Sloan;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * The simplest possible TCP network program. It listens for
+ * a connection, from telnet (telnet localhost 2317) or a program
+ * you write, which we will do later. Right now the TcpExample simply
+ * writes a string in response to a connection.
+ *
+ * Modifying this program is the basis for Assignment 1.
+ *
+ * Testing the running server program from telnet looks like this:
+ *
+ * it154916:projects mcgredo$ telnet localhost 2317
+ * Trying ::1...
+ * Connected to localhost.
+ * Escape character is '^]'.
+ * This was written by the server
+ * Connection closed by foreign host.
+ *
+ * Notice that "This was written by the server" matches
+ * what is written by the code below, over the output stream.
+ *
+ * After this first connection the program below drops out
+ * the bottom of the program, and does not repeat itself.
+ * The program exits.
+ *
+ * @author mcgredo
+ * @author brutzman@nps.edu
+ */
+public class SloanExample1Telnet
+{
+ /** Default constructor */
+ public SloanExample1Telnet()
+ {
+ // default constructor
+ }
+ /**
+ * Program invocation, execution starts here
+ * @param args command-line arguments
+ */
+ public static void main(String[] args)
+ {
+ try
+ {
+ System.out.println(SloanExample1Telnet.class.getName() + " has started and is waiting for a connection.");
+ System.out.println(" help: https://savage.nps.edu/Savage/developers.html#telnet");
+ System.out.println(" enter (telnet localhost 2317)" );
+ System.out.println("Now we'll check if your telnet connections are correct" );
+
+ // The ServerSocket waits for a connection from a client.
+ // It returns a Socket object when the connection occurs.
+ ServerSocket serverSocket = new ServerSocket(2317);
+
+ // Use Java io classes to write text (as opposed to
+ // unknown bytes of some sort) to the client
+
+ // The Socket object represents the connection between
+ // the server and client, including a full duplex connection
+ try (Socket clientConnection = serverSocket.accept()) // wait here for a client to connect
+ {
+ // OK we got something, time to respond!
+ // Use Java io classes to write text (as opposed to
+ // unknown bytes of some sort) to the client
+ OutputStream os = clientConnection.getOutputStream();
+ PrintStream ps = new PrintStream(os);
+
+ ps.println("This client response was written by server " + SloanExample1Telnet.class.getName()); // to remote client
+ System.out.println("This server response was written by server " + SloanExample1Telnet.class.getName()); // to server console
+
+ // "flush()" in important in that it forces a write
+ // across what is in fact a slow connection
+ ps.flush();
+ }
+ System.out.println(SloanExample1Telnet.class.getName() + " completed successfully.");
+ System.out.println(SloanExample1Telnet.class.getName() + " has the correct telnet build on the machine.");
+ }
+ catch(IOException e)
+ {
+ System.err.println("Exception with " + SloanExample1Telnet.class.getName() + " networking:"); // describe what is happening
+ System.err.println(e);
+ // Provide more helpful information to user if exception occurs due to running twice at one time
+
+ // brute force exception checking, can be brittle if exception message changes
+ // if (e.getMessage().equals("Address already in use: NET_Bind"))
+ 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/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample2ConnectionCounting.java b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample2ConnectionCounting.java
new file mode 100644
index 0000000000000000000000000000000000000000..3096ed701cda9dac53cf2a330fc5315570d04978
--- /dev/null
+++ b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample2ConnectionCounting.java
@@ -0,0 +1,119 @@
+package MV3500Cohort2023MarchJune.homework1.Sloan;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * Very slightly more complex than example1. 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.
+ *
+ * <code>telnet localhost 2317</code>
+ *
+ * If you're sophisticated you can contact the instructor's computer
+ * while running this program.
+ *
+ * <code>telnet ipOfServersLaptop 2317</code>
+ *
+ * And have that machine display the socket pairs received.
+ * @author mcgredo
+ * @author brutzman@nps.edu
+ */
+public class SloanExample2ConnectionCounting
+{
+ /** Default constructor */
+ public SloanExample2ConnectionCounting()
+ {
+ // default constructor
+ }
+ /**
+ * Program invocation, execution starts here
+ * @param args command-line arguments
+ */
+ public static void main(String[] args)
+ {
+ try
+ {
+ System.out.println("SloanExample2ConnectionCounting has started and is waiting for a connection.");
+ System.out.println(" help: https://savage.nps.edu/Savage/developers.html#telnet");
+ System.out.println(" Windows enter (telnet localhost 2317) for loopback operation" );
+ System.out.println("SloanExample2ConnectionCounting server standing by..." );
+
+ // ServerSocket waits for a connection from a client.
+ // Notice that it is outside the loop; ServerSocket needs to be made only once.
+
+ int connectionCount = 0; // state variable
+
+ ServerSocket serverSocket = new ServerSocket(2317); // server decides here what port to listen on.
+ // of interest: often client doesn't care what port it uses locally when connecting to that server port.
+
+ // Loop, infinitely, waiting for client connections.
+ // Stop the program somewhere else.
+ while(true)
+ {
+ // serverSocket.accept() blocks! then proceeds once a connection is "accept"ed
+ try (Socket clientConnection = serverSocket.accept()) { //the accept method blocks until a client connects
+ connectionCount++; // got another client connected one!
+
+ OutputStream os = clientConnection.getOutputStream();
+ PrintStream ps = new PrintStream(os);
+
+ if (connectionCount == 1) // first time through, report connection
+ {
+ // Where are we? In other words, what is our host number? Advertise it.
+ // Note that we use the serverSocket to get address, since host may have multiple network connections.
+ // https://stackoverflow.com/questions/9481865/getting-the-ip-address-of-the-current-machine-using-java
+ String localHostAddress = clientConnection.getInetAddress().getHostAddress();
+ System.out.println("Local host address is " + localHostAddress);
+ if (localHostAddress.contains("/"))
+ localHostAddress = localHostAddress.substring(localHostAddress.indexOf("/")+1);
+ // show localhost IP number to facilitate connections over local area network (LAN, WAN)
+ System.out.println(" enter (telnet localhost 2317) for local operation" );
+ System.out.println(" enter (telnet " + localHostAddress + " 2317)..." );
+ }
+
+ ps.println("This client response was written by server " + SloanExample2ConnectionCounting.class.getName()); // to remote client
+ System.out.println("This server response was written by server " + SloanExample2ConnectionCounting.class.getName()); // to server console
+
+ ps.println("You were connection #" + connectionCount + ", by my count");
+
+ // Print some information locally about the Socket connection.
+ // This includes the port and IP numbers on both sides (the socket pair.)
+
+ InetAddress localAddress = clientConnection.getLocalAddress();
+ InetAddress remoteAddress = clientConnection.getInetAddress();
+
+ int localPort = clientConnection.getLocalPort();
+ int remotePort = clientConnection.getPort(); // remember the prior question, why are 2 ports different?
+
+ // 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 )) note IPv6
+ // Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 54881 ))
+ //
+ // Why is first IP/port the same, while the second set has different ports?
+
+ System.out.println("Socket pair (server, client): (( " + localAddress.toString() + ", " + localPort + " ), ( " +
+ remoteAddress.toString() + ", " + remotePort + " ))");
+
+ System.out.println("got another connection, #" + connectionCount); // report progress
+
+ // Notice the use of flush() and close(). Without
+ // the close() to Socket object may stay open for
+ // a while after the client has stopped needing this
+ // connection. Close() explicitly ends the connection.
+ ps.flush();
+ }
+ }
+ }
+ catch(IOException e)
+ {
+ System.err.println("Problem with " + SloanExample2ConnectionCounting.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!");
+ }
+ }
+}
diff --git a/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample3Client.java b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample3Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..8517bf786544a25d35c3df743ad4f4239329c218
--- /dev/null
+++ b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample3Client.java
@@ -0,0 +1,103 @@
+/*
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
+ */
+package MV3500Cohort2023MarchJune.homework1.Sloan;
+
+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
+ * @author brutzman@nps.edu
+ */
+public class SloanExample3Client {
+ /** Default constructor */
+ public SloanExample3Client()
+ {
+ // 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"; //Local host
+
+ /**
+ * 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;
+
+ try {
+ while (clientLoopCount <= 9)
+ {
+ clientLoopCount++; // increment at beginning of loop for reliability
+ System.out.println(SloanExample3Client.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("==================================================");
+
+ 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 | InterruptedException e )
+ {
+ System.err.println("Problem with " + SloanExample3Client.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(SloanExample3Client.class.getName() + " exit");
+ }
+ }
+}
diff --git a/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample3Server.java b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample3Server.java
new file mode 100644
index 0000000000000000000000000000000000000000..681579b559c73e45617972162df32856668153dd
--- /dev/null
+++ b/assignments/src/MV3500Cohort2023MarchJune/homework1/Sloan/SloanExample3Server.java
@@ -0,0 +1,113 @@
+/*
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
+ */
+package MV3500Cohort2023MarchJune.homework1.Sloan;
+
+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
+ * @author brutzman@nps.edu
+ */
+public class SloanExample3Server {
+
+ /**
+ * Default constructor
+ */
+ public SloanExample3Server() {
+ // default constructor
+ }
+
+ /**
+ * Program invocation, execution starts here If already compiled, can run
+ * using console in directory ../../build/classes/ by invoking \ java
+ * -classpath . TcpExamples.TcpExample3Server
+ *
+ * @param args command-line arguments
+ */
+ 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(SloanExample3Server.class.getName() + " has started..."); // it helps debugging to put this on console first
+
+ ServerSocket serverSocket = new ServerSocket(2317);
+ OutputStream os;
+ PrintStream ps;
+ InetAddress localAddress, remoteAddress;
+ int localPort, remotePort;
+ int serverLoopCount = 0;
+
+ // Server is up and waiting (i.e. "blocked" or paused)
+ // Loop, infinitely, waiting for client connections.
+ // Stop the program somewhere else.
+ while (serverLoopCount <=9) {
+
+ // block until connected to a client
+ try (Socket clientConnectionSocket = serverSocket.accept()) {
+ serverLoopCount++; // increment at beginning of loop for reliability
+
+ // Now hook everything up (i.e. set up the streams), Java style:
+ os = clientConnectionSocket.getOutputStream();
+ ps = new PrintStream(os);
+ ps.println("This is response " + serverLoopCount + " produced by the server."); // 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 = clientConnectionSocket.getLocalAddress();
+ remoteAddress = clientConnectionSocket.getInetAddress();
+ localPort = clientConnectionSocket.getLocalPort();
+ remotePort = clientConnectionSocket.getPort();
+
+ System.out.print("Server loop " + serverLoopCount + ": ");
+
+ // 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(SloanExample3Server.class.getName() + " socket pair showing host name, address, port:");
+ System.out.println(" (( "
+ + localAddress.getHostName() + "=" + localAddress.getHostAddress() + ", " + localPort + " ), ( "
+ + remoteAddress.getHostName() + "=" + remoteAddress.getHostAddress() + ", " + remotePort + " ))");
+
+ if (localAddress.getHostName().equals(localAddress.getHostAddress())
+ || remoteAddress.getHostName().equals(remoteAddress.getHostAddress())) {
+ System.out.println(" note HostName matches address if host has no DNS name");
+ }
+ // 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!
+ }
+ }
+ } catch (IOException e) {
+ System.err.println("Problem with " + SloanExample3Server.class.getName() + " 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!");
+ }
+ }
+ }
+}