diff --git a/MV3500Cohort2021JulySeptember/homework1/FrankClient.java b/MV3500Cohort2021JulySeptember/homework1/FrankClient.java
new file mode 100644
index 0000000000000000000000000000000000000000..aa3fdc86cb7ea1e63fbe5120a56086d5b184b321
--- /dev/null
+++ b/MV3500Cohort2021JulySeptember/homework1/FrankClient.java
@@ -0,0 +1,100 @@
+
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.Socket;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author justi
+ */
+
+
+
+public class FrankClient {
+
+ /**
+ */
+
+ public 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
+ */
+ 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;
+
+ try {
+ while (true)
+ {
+ clientLoopCount++; // increment at beginning of loop for reliability
+ System.out.println(FrankClient.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, 2318); // 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
+
+ } // end while(true) // infinite loops are dangerous, be sure to kill this process!
+ }
+ catch (IOException e)
+ {
+ System.err.println("Problem with " + FrankClient.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( "FrankClient.class.getName() + exit");
+ }
+ }
+}
diff --git a/MV3500Cohort2021JulySeptember/homework1/FrankServer.java b/MV3500Cohort2021JulySeptember/homework1/FrankServer.java
new file mode 100644
index 0000000000000000000000000000000000000000..ddbe0d62b7a2728ad4e160be0193e504d142c26b
--- /dev/null
+++ b/MV3500Cohort2021JulySeptember/homework1/FrankServer.java
@@ -0,0 +1,101 @@
+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 2318
+ *
+ * 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
+ */
+public class FrankServer {
+
+ /**
+ * 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(FrankServer.class.getName() + " has started..."); // it helps debugging to put this on console first
+
+ ServerSocket serverSocket = new ServerSocket(2318);
+ 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 (true) {
+
+ // 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(FrankServer.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");
+
+ // Not/*i*/ce 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 " + FrankServer.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!");
+ }
+ }
+ }
+}
diff --git a/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java b/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..72a96f5e3812aa01ba7a5961d5ac2fff95987157
--- /dev/null
+++ b/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java
@@ -0,0 +1,100 @@
+package MV3500Cohort2021JulySeptember.homework1;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.Socket;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author justi
+ */
+
+
+
+public class FrankTCPExample3Client {
+
+ /**
+ */
+
+ public 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
+ */
+ 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;
+
+ try {
+ while (true)
+ {
+ clientLoopCount++; // increment at beginning of loop for reliability
+ System.out.println(FrankTCPExample3Client.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, 2318); // 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
+
+ } // end while(true) // infinite loops are dangerous, be sure to kill this process!
+ }
+ catch (IOException e)
+ {
+ System.err.println("Problem with " + FrankTCPExample3Client.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( "FrankTCPExample3Client.class.getName() + exit");
+ }
+ }
+}
diff --git a/assignments/ReportingForDuty.md b/assignments/ReportingForDuty.md
index cbdf09a2c4516efa178cfeea6af33fbb118dbf6a..c45dcff8693fa2bea4626a90453f5dbed396af8c 100644
--- a/assignments/ReportingForDuty.md
+++ b/assignments/ReportingForDuty.md
@@ -1,6 +1,6 @@
## Reporting For Duty
-Everyone in the course is hereby requested to make a change to this file. This confirms your ability to use Netbeans and your gitlab.nps.edu account.
+Everyone in the course is hereby requested to make a change to this file. This confirms your ability to use NetBeans and your gitlab.nps.edu account.
Be sure to *git update* before, and be sure to *git commit* and *git push* after!
@@ -9,11 +9,24 @@ More information on your use of Git is in the parent directory [README.md](../..
- Don Brutzman
---
### 2021
+
+- Terry is here!
+
- Kurt Reynolds
---
+- Nick Hittner
+
+- Matt Robinson
+
+- Alex Fisher
+
+--John Morris
+
+- Max Schlessel
+
### 2020
- Bernd Weissenberger
diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java
new file mode 100644
index 0000000000000000000000000000000000000000..483b40bf6e0256e6fd6486ebb3d5917e21040dd0
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java
@@ -0,0 +1,64 @@
+package MV3500Cohort2021JulySeptember.homework1;
+
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+/**
+ *
+ * @author adfis
+ */
+
+
+public class FisherTCPExample1Telnet {
+ public static void main(String[] args)
+ {
+ try
+ {
+ System.out.println("TcpExample1Telnet 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) or (nc localhost 2317)..." );
+
+ // 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()) {
+ // 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("Client response was written by Alex' server TcpExample1."); // to remote clientnc
+ ps.println("We are crushing this assignment, good work.");
+ System.out.println("Server response was written by Alex' server TcpExample1."); // to server console
+ System.out.println("SUCCESS!");
+
+ // "flush()" in important in that it forces a write
+ // across what is in fact a slow connection
+ ps.flush();
+ }
+ System.out.println("TcpExample1 completed successfully.");
+ }
+ catch(IOException e)
+ {
+ System.err.println("Problem with TcpExample1Telnet 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
+
+ // 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/MV3500Cohort2021JulySeptember/homework1/KeevenTCPExample3Client.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/KeevenTCPExample3Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..baa963c2f6dbaebe3157da7c2e9b31a7e1797322
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/KeevenTCPExample3Client.java
@@ -0,0 +1,99 @@
+package MV3500Cohort2021JulySeptember.homework1;
+
+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
+ */
+public class KeevenTCPExample3Client {
+
+ /** 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) throws InterruptedException {
+
+ // Local variables/fields
+ Socket socket = null;
+ InputStream is;
+ Reader isr;
+ BufferedReader br;
+ String serverMessage;
+ int clientLoopCount = 0;
+ int numbLoops = 10;
+
+ try {
+ while (clientLoopCount < numbLoops)
+ {
+ clientLoopCount++; // increment at beginning of loop for reliability
+ System.out.println(KeevenTCPExample3Client.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("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(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 e)
+ {
+ System.err.println("Problem with " + KeevenTCPExample3Client.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(KeevenTCPExample3Client.class.getName() + " exit");
+ }
+ }
+}
diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/KeevenTCPExample3Server.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/KeevenTCPExample3Server.java
new file mode 100644
index 0000000000000000000000000000000000000000..a3423cf6b5fdd89f12ea4e8019ea9c5f61c697b5
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/KeevenTCPExample3Server.java
@@ -0,0 +1,107 @@
+package MV3500Cohort2021JulySeptember.homework1;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * This is Assignment 1 where I have modified the given code from TCPExample3Server
+ *-server response message changed
+ *
+ * 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
+ */
+public class KeevenTCPExample3Server {
+
+ /**
+ * 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(KeevenTCPExample3Server.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 (true) {
+
+ // 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, "
+ + KeevenTCPExample3Server.class.getName()); // 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(KeevenTCPExample3Server.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 " + KeevenTCPExample3Server.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!");
+ }
+ }
+ }
+}
diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/MorrisTcpExample1Telnet.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/MorrisTcpExample1Telnet.java
new file mode 100644
index 0000000000000000000000000000000000000000..38bbcc2768c17a68917f54b005e31564dbfa7a3d
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/MorrisTcpExample1Telnet.java
@@ -0,0 +1,86 @@
+package MV3500Cohort2021JulySeptember.homework1;;
+
+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 his 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
+ */
+public class MorrisTcpExample1Telnet
+{
+ /**
+ * Program invocation, execution starts here
+ * @param args command-line arguments
+ */
+ public static void main(String[] args)
+ {
+ try
+ {
+ System.out.println("TcpExample1Telnet 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) or (nc localhost 2317)..." );
+
+ // 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 Johnny Smiles "); // to remote client
+ ps.println("MOVES 2021 Cohort is full of badassery.");
+ System.out.println("This server response was written by Johnny Smiles " ); // 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(" completed successfully.");
+ }
+ catch(IOException e)
+ {
+ System.err.println(" Pardon the interruption, networking issue"); // 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/MV3500Cohort2021JulySeptember/homework1/README.md b/assignments/src/MV3500Cohort2021JulySeptember/homework1/README.md
index c0f16cb152eac14324694057a50ac035fffc719c..e5bd42a3887286271cc8c591aea01fa2b56f783c 100644
--- a/assignments/src/MV3500Cohort2021JulySeptember/homework1/README.md
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/README.md
@@ -1,5 +1,7 @@
## Homework 1: Unicast Networking
+Welcome everybody! This is where your homework goes.
+
Deliverables:
* Update unicast sockets sender/receiver, modifying provided code, test via telnet.
diff --git a/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..67275fa64d71b19b353d4a84947fa57fab80d2df
--- /dev/null
+++ b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java
@@ -0,0 +1,96 @@
+package MV3500Cohort2021JulySeptember.homework1;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.Socket;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author justi
+ */
+public class FrankTCPExample3Client {
+
+ /**
+ */
+ public 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
+ */
+ 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;
+
+ try {
+ while (true) {
+ clientLoopCount++; // increment at beginning of loop for reliability
+ System.out.println(FrankTCPExample3Client.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, 2318); // 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)
+ if (serverMessage.equals("this is good bye message from the server")) { //if client recieved termanation message stop client
+ break;
+ }
+ Thread.sleep(1000); // turned it down to 1 second
+
+ } // end while(true) // infinite loops are dangerous, be sure to kill this process!
+ } catch (IOException e) {
+ System.err.println("Problem with " + FrankTCPExample3Client.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("FrankTCPExample3Client.class.getName() + exit");
+ }
+ }
+}
diff --git a/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.JPG b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.JPG
new file mode 100644
index 0000000000000000000000000000000000000000..a2652f97a08b14422f64213a8f3d0050257e8563
Binary files /dev/null and b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.JPG differ
diff --git a/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.java b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.java
new file mode 100644
index 0000000000000000000000000000000000000000..45c8aa10fe6e56ddac91ec864216aac7eb93cafd
--- /dev/null
+++ b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.java
@@ -0,0 +1,107 @@
+package MV3500Cohort2021JulySeptember.homework1;
+
+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 2318
+ *
+ * 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
+ */
+public class FrankTCPExample3Server {
+
+ /**
+ * 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) 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(FrankTCPExample3Server.class.getName() + " has started..."); // it helps debugging to put this on console first
+
+ ServerSocket serverSocket = new ServerSocket(2318); // changed from 2317 to 2318
+ 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 (true) {
+
+ // 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);
+ if (serverLoopCount <= 20) { // checking if the loop count <= 20
+ ps.println("This is response " + serverLoopCount + " produced by the server."); // this gets sent back to client!
+ } else {
+ ps.println("this is good bye message from the server"); // termination after 20 messages
+ break; // Stop server
+ }
+ // 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(FrankTCPExample3Server.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");
+ }
+
+ // Not/*i*/ce 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 " + FrankTCPExample3Server.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!");
+ }
+ }
+ }
+}
diff --git a/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3ServerClient.JPG b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3ServerClient.JPG
new file mode 100644
index 0000000000000000000000000000000000000000..3a5853becfde3cdc97b73849da1f168963efe360
Binary files /dev/null and b/examples/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3ServerClient.JPG differ
diff --git a/examples/src/TcpExamples/Assignment1TCPExample3ClientChange.java b/examples/src/TcpExamples/Assignment1TCPExample3ClientChange.java
new file mode 100644
index 0000000000000000000000000000000000000000..10b89e0ed0515e96475cd5ebd66fb4d7935f91ba
--- /dev/null
+++ b/examples/src/TcpExamples/Assignment1TCPExample3ClientChange.java
@@ -0,0 +1,99 @@
+package TcpExamples;
+
+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
+ */
+public class Assignment1TCPExample3ClientChange {
+
+ /** 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) throws InterruptedException {
+
+ // Local variables/fields
+ Socket socket = null;
+ InputStream is;
+ Reader isr;
+ BufferedReader br;
+ String serverMessage;
+ int clientLoopCount = 0;
+ int numbLoops = 10;
+
+ try {
+ while (clientLoopCount < numbLoops)
+ {
+ clientLoopCount++; // increment at beginning of loop for reliability
+ System.out.println(Assignment1TCPExample3ClientChange.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("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(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 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");
+ }
+ }
+}
diff --git a/examples/src/TcpExamples/Assignmnet1TCPExample3ServerChange.java b/examples/src/TcpExamples/Assignmnet1TCPExample3ServerChange.java
new file mode 100644
index 0000000000000000000000000000000000000000..5104cf24be9380a4c9190e9f2619caacf02cece8
--- /dev/null
+++ b/examples/src/TcpExamples/Assignmnet1TCPExample3ServerChange.java
@@ -0,0 +1,107 @@
+package TcpExamples;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * This is Assignment 1 where I have modified the given code from TCPExample3Server
+ *-server response message changed
+ *
+ * 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
+ */
+public class Assignmnet1TCPExample3ServerChange {
+
+ /**
+ * 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(Assignmnet1TCPExample3ServerChange.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 (true) {
+
+ // 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, "
+ + Assignmnet1TCPExample3ServerChange.class.getName()); // 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(TcpExample3Server.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 " + TcpExample3Server.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!");
+ }
+ }
+ }
+}