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 e5426929e08967b1567fb7456039e80834003ec7..8369cc13910e56e1e0137091caa2f65199152141 100644 --- a/assignments/ReportingForDuty.md +++ b/assignments/ReportingForDuty.md @@ -12,6 +12,8 @@ More information on your use of Git is in the parent directory [README.md](../.. ### 2021 +- Terry is here! + - Kurt Reynolds - Rick Lentz @@ -26,6 +28,8 @@ More information on your use of Git is in the parent directory [README.md](../.. --John Morris +- Max Schlessel + ### 2020 - Bernd Weissenberger diff --git a/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java b/assignments/src/MV3500Cohort2021JulySeptember/homework1/FisherTCPExample1Telnet.java index d925c7fdc0b4cb83e4cd3eec4a662be1c4b49a09..483b40bf6e0256e6fd6486ebb3d5917e21040dd0 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 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!"); - } - } -} - +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/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