Merge origin/master

assignments/src/MV3500Cohort2023MarchJune/homework1/Islas/HW1Client.java

+package MV3500Cohort2023MarchJune.homework1.Islas;
+
+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 HW1Client {
+      /** Default constructor */
+      public HW1Client()
+      {
+          // 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 (true)
+              {
+                  clientLoopCount++; // increment at beginning of loop for reliability
+                //   System.out.println(HW1Client.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("==================================================");
+
+                  // First pose
+                  if (clientLoopCount % 2 == 0) {
+                    System.out.println("   O/   "); // head
+                    System.out.println("  /|  "); // arms
+                    System.out.println("  /_\\  "); // legs
+                    System.out.println("  | |  "); // torso
+                    System.out.println();
+                }
+
+                // Second pose
+                else {
+                    System.out.println("  \\O   "); // head
+                    System.out.println("   |\\  "); // arms
+                    System.out.println("  /_\\  "); // legs
+                    System.out.println("  | |  "); // torso
+                    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 " + HW1Client.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(HW1Client.class.getName() + " exit");
+          }
+      }
+}

assignments/src/MV3500Cohort2023MarchJune/homework1/Islas/HW1Server.java

+package MV3500Cohort2023MarchJune.homework1.Islas;
+
+
+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 HW1Server {
+        /** Default constructor */
+        public HW1Server()
+        {
+            // 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(HW1Server.class.getName() + " has started..."); // it helps debugging to put this on console first
+                System.out.println("May I have this dance?");
+                ServerSocket serverSocket = new ServerSocket(2317);
+                OutputStream os;
+                PrintStream ps;
+                InetAddress localAddress, remoteAddress;
+                int localPort, remotePort;
+                int serverLoopCount = 0;
+    
+                boolean keepGoing = true;
+                // Server is up and waiting (i.e. "blocked" or paused)
+                // Loop, infinitely, waiting for client connections.
+                // Stop the program somewhere else.
+                while (keepGoing) { 
+                    // 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();
+                        
+                        if (serverLoopCount > 100) {
+                            keepGoing = false;
+                        }
+                        // First pose
+                        if (serverLoopCount % 2 == 0) {
+                            System.out.println("   O/   "); // head
+                            System.out.println("  /|  "); // arms
+                            System.out.println("  / \\  "); // legs
+                            System.out.println("  | |  "); // torso
+                            System.out.println();
+                        }
+
+                        // Second pose
+                        else {
+                            System.out.println("  \\O   "); // head
+                            System.out.println("   |\\  "); // arms
+                            System.out.println("  / \\  "); // legs
+                            System.out.println("  | |  "); // torso
+                            System.out.println();
+                        }
+
+
+                        // 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(HW1Server.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 " + HW1Server.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!");
+                }
+            }
+        }
+}

presentations/01_README_LVC.md

@@ -22,6 +22,7 @@ correctly added together.
 7. Aircraft operations: fueling, maintenance, resupply, flying, takeoff/landing, fighting etc.
 8. NATO Live Training Exercise, for example [CWIX 2022](https://www.jftc.nato.int/articles/cwix-2022) as part of [NATO FEDERATED INTEROPERABILITY](https://www.act.nato.int/federated-interoperability)
 9. MOUT (Military Operations on Urban Terrain)
+10. (Your Example Here)
 
 ## Virtual
 
@@ -32,7 +33,7 @@ correctly added together.
 5. Small Arms fire simulator (i.e AGSHP (germany))
 6. Aircraft operations: fueling, maintenance, resupply, flying, takeoff/landing, fighting etc.
 7. Non-Combatant Evacuation Operations [NEO](https://www.defense.gov/News/News-Stories/Article/Article/2793440/dod-leaders-address-bagram-departure-noncombatant-evacuation-operation-timing/)
-8. 
+8. (Your Example Here)
 
 ## Constructive
 
@@ -48,4 +49,6 @@ correctly added together.
 
 * [In God We Trust... All Others Bring Data](https://en.wikiquote.org/wiki/W._Edwards_Deming#Misattributed)
 * Is there anything we do in DoD that is NOT a candidate for LVC?  Hmmm...
-* Interesting to observe that typical progresssion in regular practice is Virtual rehearsal first then Live conduct, VLC perhaps
+* Interesting to observe that typical progresssion in regular practice is Virtual rehearsal first then Live conduct, VLC perhaps.
+* I used to dislike the term "LVC" because it meant everything to everybody.
+  Now I really like the term "LVC" because... it means everything to everbody!