diff --git a/assignments/ReportingForDuty.md b/assignments/ReportingForDuty.md
index 58d92923cbeb8a6b387c7be5b835e809399c7688..39e8aef3f508fde6d6175350a63cad0199ce7b21 100644
--- a/assignments/ReportingForDuty.md
+++ b/assignments/ReportingForDuty.md
@@ -7,11 +7,11 @@ Be sure to *git update* before, and be sure to *git commit* and *git push* after
More information on your use of Git is in the parent directory [README.md](../../README.md)
- Don Brutzman
-
---
-
### 2021
+- Terry is here!
+
- Kurt Reynolds
- Rick Lentz
@@ -24,10 +24,12 @@ More information on your use of Git is in the parent directory [README.md](../..
- Alex Fisher
---John Morris
+- John Morris
- Max Schlessel
+- Justin McNeely
+
- John Allen
### 2020
diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java
index 483b40bf6e0256e6fd6486ebb3d5917e21040dd0..d925c7fdc0b4cb83e4cd3eec4a662be1c4b49a09 100644
--- a/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java
@@ -1,64 +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!");
- }
- }
-}
-
+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 FisherTCPExample1Telnet 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/FrankTCPExample3Client.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..67275fa64d71b19b353d4a84947fa57fab80d2df
--- /dev/null
+++ b/assignments/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/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.JPG b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.JPG
new file mode 100644
index 0000000000000000000000000000000000000000..a2652f97a08b14422f64213a8f3d0050257e8563
Binary files /dev/null and b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.JPG differ
diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3Server.java
new file mode 100644
index 0000000000000000000000000000000000000000..45c8aa10fe6e56ddac91ec864216aac7eb93cafd
--- /dev/null
+++ b/assignments/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/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3ServerClient.JPG b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3ServerClient.JPG
new file mode 100644
index 0000000000000000000000000000000000000000..3a5853becfde3cdc97b73849da1f168963efe360
Binary files /dev/null and b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FrankTCPExample3ServerClient.JPG differ
diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/HittnerDomTcpExample1Telnet.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/HittnerDomTcpExample1Telnet.java
new file mode 100644
index 0000000000000000000000000000000000000000..3ba4381f1ad60668101abdd5a16b4a0283e5f2cd
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/HittnerDomTcpExample1Telnet.java
@@ -0,0 +1,63 @@
+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 HittnerDomTcpExample1Telnet {
+ 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 brought to you by the Domo"); // to remote clientnc
+ ps.println("DomsaMom");
+ System.out.println("Client response was brought to you by the Domo"); // to server console
+ System.out.println("DomsaMom");
+
+ // "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/HittnerNickTcpExample1Telnet.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/HittnerNickTcpExample1Telnet.java
new file mode 100644
index 0000000000000000000000000000000000000000..495dcb25294407aa06f1e22268a6eb25ebdfdbd7
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/HittnerNickTcpExample1Telnet.java
@@ -0,0 +1,63 @@
+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 HittnerNickTcpExample1Telnet {
+ 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 brought to you by the Highlander"); // to remote clientnc
+ ps.println("There Can Be Only One");
+ System.out.println("Client response was brought to you by the Highlander"); // to server console
+ System.out.println("There Can be Only One");
+
+ // "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/LeckieTcpExample2.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/LeckieTcpExample2.java
new file mode 100644
index 0000000000000000000000000000000000000000..037e875c50c1d270f877119b837a3e2cda1ca00f
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/LeckieTcpExample2.java
@@ -0,0 +1,103 @@
+package pkg3500.leckie;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+/**
+ * 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
+ * @author leckie
+ */
+public class LeckieTcpExample2
+{
+ public static void main(String[] args)
+ {
+ try
+ {
+ System.out.println("TcpExample2ConnectionCounting has started and is waiting for a connection.");
+ System.out.println(" help: https://savage.nps.edu/Savage/developers.html#telnet");
+ System.out.println(" enter (nc localhost 2317) or (telnet localhost 2317)..." );
+
+ // 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
+ int totalEntrantCount = 31; // spoofed entrants
+
+ 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)
+ {
+ // blocks! then proceeds once a connection is "accept"ed
+ try (Socket clientConnection = serverSocket.accept()) {
+ connectionCount++; // got another one!
+
+ OutputStream os = clientConnection.getOutputStream();
+ PrintStream ps = new PrintStream(os);
+
+ ps.println("This client response was written by server " + LeckieTcpExample2.class.getName()); // to remote client
+ System.out.println("This server response was written by server " + LeckieTcpExample2.class.getName()); // to server console
+
+ ps.println("This is your lottery attempt number #" + connectionCount + ", you are aplicant number " + totalEntrantCount + " to try and win. Keep trying!");
+
+ totalEntrantCount = (totalEntrantCount + 79);
+ // 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: (( " + 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 " + LeckieTcpExample2.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/MV3500Cohort2021JulySeptember/homework1/TcpExample2_Leckie_Mod_Hw1.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/TcpExample2_Leckie_Mod_Hw1.java
new file mode 100644
index 0000000000000000000000000000000000000000..6fed11d3d705393f355c5db404295fd373f5159c
--- /dev/null
+++ b/assignments/src/MV3500Cohort2021JulySeptember/homework1/TcpExample2_Leckie_Mod_Hw1.java
@@ -0,0 +1,103 @@
+package pkg3500.leckie;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+/**
+ * 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
+ * @author leckie
+ */
+public class TcpExample2_Leckie_Mod_Hw1
+{
+ public static void main(String[] args)
+ {
+ try
+ {
+ System.out.println("TcpExample2ConnectionCounting has started and is waiting for a connection.");
+ System.out.println(" help: https://savage.nps.edu/Savage/developers.html#telnet");
+ System.out.println(" enter (nc localhost 2317) or (telnet localhost 2317)..." );
+
+ // 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
+ int totalEntrantCount = 31; // spoofed entrants
+
+ 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)
+ {
+ // blocks! then proceeds once a connection is "accept"ed
+ try (Socket clientConnection = serverSocket.accept()) {
+ connectionCount++; // got another one!
+
+ OutputStream os = clientConnection.getOutputStream();
+ PrintStream ps = new PrintStream(os);
+
+ ps.println("This client response was written by server " + TcpExample2_Leckie_Mod_Hw1.class.getName()); // to remote client
+ System.out.println("This server response was written by server " + TcpExample2_Leckie_Mod_Hw1.class.getName()); // to server console
+
+ ps.println("This is your lottery attempt number #" + connectionCount + ", you are aplicant number " + totalEntrantCount + " to try and win. Keep trying!");
+
+ totalEntrantCount = (totalEntrantCount + 79);
+ // 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: (( " + 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 " + TcpExample2_Leckie_Mod_Hw1.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!");
+ }
+ }
+
+}