diff --git a/assignments/ReportingForDuty.md b/assignments/ReportingForDuty.md index 1eaae97a1051976aa94ad72d9ebbce4ab9b289bd..9dce2a4490181e610de469490c6affdbad0b8f97 100644 --- a/assignments/ReportingForDuty.md +++ b/assignments/ReportingForDuty.md @@ -7,27 +7,27 @@ 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 -- Dom Hittner - - Nick Hittner - Matt Robinson - Alex Fisher ---John Morris +- John Morris - Max Schlessel +- Justin McNeely + ### 2020 - Bernd Weissenberger 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/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!"); + } + } + +}