Merge origin/master

Conflicts:
	examples/src/UdpMulticastExamples/UdpSender.java

assignments/src/MV3500Cohort2020JulySeptember/homework2/Weissenberger/LokiServerThread.java

@@ -6,7 +6,7 @@ import java.net.*;
 /**
  * A program that handles all logic associated with one socket connection
  * by running in a thread of its own. This is the server
- * portion
+ * portion (little changes)
  * 
  * @author Bernd Weissenberger
  */

assignments/src/MV3500Cohort2020JulySeptember/homework3/Garibay/UDPReceiverGaribay.java

+
+package MV3500Cohort2020JulySeptember.homework3.Garibay;
+
+import java.io.ByteArrayInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+
+/**
+ *
+ * @author chris
+ */
+public class UDPReceiverGaribay 
+{
+//  public static final int       SENDING_PORT = 1414; // port used by UdpSender, unneeded here
+    public static final int     RECEIVING_PORT = 1415;
+    public static final String DESINATION_HOST = "localhost";
+
+    /**
+     * @param args the command line arguments
+     * @throws java.io.IOException
+     */
+    public static void main(String[] args) throws IOException 
+    {
+        DatagramSocket udpSocket = null;
+        
+        try
+        {
+            System.out.println(UdpReceiver.class.getName() + " started...");
+            
+            // Create a UDP socket
+            udpSocket = new DatagramSocket(RECEIVING_PORT);
+            udpSocket.setReceiveBufferSize(1500); // how many bytes are in buffer?  MTU=1500 is good
+            udpSocket.setBroadcast(false);        // we're just receiving here
+            
+            byte[] byteArray = new byte[1500];
+            DatagramPacket receivePacket = new DatagramPacket(byteArray, byteArray.length);
+            
+            ByteArrayInputStream bais = new ByteArrayInputStream(byteArray);
+            DataInputStream dis = new DataInputStream(bais);
+            
+            boolean       isEvenParity;
+            int           packetCount = 0;
+            int           firstInt;   
+            float         secondFloat;
+            String        thirdString;
+            String        padding;
+            
+            // You need a new receiving packet to read from every packet received
+            while (true)
+            {
+                packetCount++; // good practice to increment counter at start of loop, when possible
+                udpSocket.receive(receivePacket); // blocks until packet is received
+                
+                // values of interest follow. order and types of what was sent must match what you are reading!
+                firstInt     = dis.readInt();     // packetID
+                secondFloat  = dis.readFloat();
+                thirdString  = dis.readUTF();     // string value with guaranteed encoding, matches UTF-8 is 8 bit
+                isEvenParity = dis.readBoolean(); // ok, we've gotten everything we're looking for.  
+                
+                dis.reset(); // now clear the input stream after reading, in preparation for next loop
+                
+                if  (isEvenParity) 
+                     padding = " ";
+                else padding = "";
+                
+                System.out.println("[" + UdpReceiver.class.getName() + "]" + 
+                                               " packetID="   + firstInt +            // have output message use same name as sender
+                                     ", second float value="   + secondFloat  + 
+                                     ", third String value=\"" + thirdString  + "\"" + // note that /" is literal quote character
+                                    " isPacketIdEvenParity="   + isEvenParity + ","  + padding +
+                                     " packet counter="        + packetCount);
+            }
+        }
+        catch(IOException e)
+        {
+            System.err.println("Problem with UdpReceiver, see exception trace:");
+            System.err.println(e);
+        } 
+        finally // clean up prior to exit, don't want to leave behind zombie socket
+        {
+            if (udpSocket != null)
+                udpSocket.close();
+            System.out.println(UdpReceiver.class.getName() + " complete."); // all done
+        }
+    }
+}

assignments/src/MV3500Cohort2020JulySeptember/homework3/Garibay/UDPSenderGaribay.java

+
+package MV3500Cohort2020JulySeptember.homework3.Garibay;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+
+/**
+ *
+ * @author chris
+ */
+public class UDPSenderGaribay 
+{
+    // System properties: https://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html
+    public static final String            MY_NAME = System.getProperty("user.name"); // guru incantation   8)
+//  public static final int          SENDING_PORT = 1414; // not needed, can let system choose an open local port
+    public static final int        RECEIVING_PORT = 1415;
+    public static final int TOTAL_PACKETS_TO_SEND = 100;
+    
+    // here is what we need for lab comms
+    // Bill Mahan's host ip
+    public static final String   DESTINATION_HOST = "10.1.105.13"; // localhost 127.0.0.1 or argon 10.1.105.1 or 10.1.105.1 or whatever
+    
+    @SuppressWarnings("SleepWhileInLoop")
+    public static void main(String[] args) throws IOException 
+    {
+        DatagramSocket udpSocket = null;
+        DataOutputStream  dos = null;
+        int   packetID = 0;     // counter variable to send in packet
+        float    value = -1.0f; // unreachable value is good sentinel to ensure expected changes occur
+        String message = MY_NAME + "It's not a trick question!"; // no really
+        String padding = new String();
+        
+        try
+        {
+            System.out.println(UdpSender.class.getName() + " shows how to send simple-type values via DataOutputStream");
+            System.out.println(UdpSender.class.getName() + " started...");
+            
+            // Create a UDP socket
+            udpSocket = new DatagramSocket(); // let system assign output port, then SENDING_PORT not needed
+            
+            // Put together a message with binary content. "ByteArrayOutputStream"
+            // is a java.io utility that lets us put together an array of binary
+            // data, which we put into the UDP packet.
+            
+            ByteArrayOutputStream baos = new ByteArrayOutputStream(1500); // how many bytes are in buffer?  MTU=1500 is good
+            dos = new DataOutputStream(baos); // wrapper for writing values, connects both streams
+			
+            // Put together a packet to send
+            // these types and order of variables must match on sender and receiver
+            byte[] byteArray = baos.toByteArray();
+            
+            // ID of the host we are sending to
+            InetAddress destinationAddress = InetAddress.getByName(DESTINATION_HOST);
+            // ID of the host we are sending from
+            InetAddress      sourceAddress = InetAddress.getByName("localhost"); // possibly identical if source not modified
+            
+            DatagramPacket datagramPacket = new DatagramPacket(byteArray, byteArray.length, destinationAddress, RECEIVING_PORT);
+       
+            // Hmmm, how fast does UDP stream go? Does UDP effectively slow packets down, or does
+            // this cause network problems? (hint: yes for an unlimited send rate, unlike TCP).
+            // How do you know on the receiving side that you haven't received a
+            // duplicate UDP packet, out-of-order packet, or dropped packet? your responsibility.
+            
+            for (int index = 1; index <= TOTAL_PACKETS_TO_SEND; index++) // avoid infinite send loops in code, they can be hard to kill!
+            {
+                packetID++;                               // increment counter, prefer using explicit value to index
+                value = TOTAL_PACKETS_TO_SEND - packetID; // countdown
+                boolean isPacketIdEvenParity = ((packetID % 2) == 0); // % is modulo operator; result 0 is even parity, 1 is odd parity
+                
+                // values of interest follow. order and types of what was sent must match what you are reading!
+                dos.writeInt    (packetID);
+                dos.writeFloat  (value);
+                dos.writeUTF    (message); // string value with guaranteed encoding, matches UTF-8 is 8 bit
+                dos.writeBoolean(isPacketIdEvenParity);
+                
+                dos.flush(); // sends DataOutputStream to ByteArrayOutputStream
+                byteArray = baos.toByteArray();    // OK so go get the flushed result...
+                datagramPacket.setData(byteArray); // and put it in the packet...
+                udpSocket.send(datagramPacket);    // and send it away. boom gone, nonblocking.
+//              System.out.println("udpSocket output port=" + udpSocket.getLocalPort()); // diagnostic tells what port was chosen by system
+                
+                if  (isPacketIdEvenParity)
+                     padding = " ";
+                else padding = "";
+            
+                Thread.sleep(1000); // Send packets at rate of one per second
+                System.out.println("[" + UdpSender.class.getName() + "] " + MY_NAME + " " + sourceAddress + 
+                                   " sent values(" + packetID + "," + value + ",\"" + message + "\"," + isPacketIdEvenParity +
+                                   ")" + padding + " as packet #" + index + " of " + TOTAL_PACKETS_TO_SEND);
+                baos.reset(); // clear the output stream after sending
+            }
+        }
+        catch (IOException | InterruptedException e)
+        {
+            System.err.println("Problem with UdpSender, see exception trace:");
+            System.err.println(e);
+        } 
+        finally // clean up prior to exit, don't want to leave behind zombies
+        {
+            if (udpSocket != null)
+                udpSocket.close();
+            
+            if (dos != null)
+                dos.close();
+            System.out.println(UdpSender.class.getName() + " complete."); // all done
+        }
+    }
+}

assignments/src/MV3500Cohort2020JulySeptember/homework3/Goericke/TCPNumberReceiverUDPResultSender.java

+package MV3500Cohort2020JulySeptember.homework3.Goericke;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+/**
+ * This class will be connected by an TCP sender over VPN (argon), calculating 
+ * a result of an equation and send the result back via UDP over VPN. 
+ * @date 08/17/2020
+ * @group Goericke/Weissenberger
+ */
+public class TCPNumberReceiverUDPResultSender {
+
+    // Change this to the port where the TCP server is listening
+    private static final int TCP_ARGON_SERVER_PORT = 2317;
+
+    /**
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) {
+        try {
+            
+            // ServerSocket waits for a connection from a client. 
+            System.out.println("TCPNumberReceiver has started...");
+            ServerSocket serverSocket = new ServerSocket(TCP_ARGON_SERVER_PORT);
+            InetAddress remoteAddress;
+            
+            // declare the stream and readers
+            InputStream inputStream;
+            InputStreamReader inputStreamReader;
+            BufferedReader bufferedReader;
+            
+            // declare needed variables
+            String clientMessage;
+            int number1, number2;
+            String calculation_Method;
+            int iUDPResultReceivingPort;
+            // Server is up and waiting (i.e. "blocked" or paused)
+            // Loop, infinitely, waiting for client connections.
+            while (true) { 
+                
+                // block until connected to a client
+                try (Socket clientConnectionSocket = serverSocket.accept())
+                {
+                    // Now hook everything up (i.e. set up the streams), Java style:
+                    inputStream  = clientConnectionSocket.getInputStream();
+                    inputStreamReader = new InputStreamReader(inputStream);
+                    bufferedReader  = new BufferedReader(inputStreamReader);
+                    
+                    // get the date from TCP packet
+                    clientMessage = bufferedReader.readLine();
+                    number1 = Integer.parseInt(bufferedReader.readLine());
+                    number2 = Integer.parseInt(bufferedReader.readLine());
+                    calculation_Method = bufferedReader.readLine();
+                    iUDPResultReceivingPort = Integer.parseInt(bufferedReader.readLine());
+                    
+                    // print them out (for debugging)
+                    System.out.println("Message recived: "+clientMessage);
+                    System.out.println("Number 1 recived: "+number1);
+                    System.out.println("Number 2 recived: "+number2);
+                    System.out.println("Calc Method recived: "+calculation_Method);
+                    System.out.println("Send result to port: "+iUDPResultReceivingPort);
+                    // get the sender IP (is used for sending UDP)
+                    remoteAddress = clientConnectionSocket.getInetAddress();
+                    
+                    System.out.println("Send result to IP: "+remoteAddress.getHostAddress());
+                    
+                    // try to send the calculated result as a float via UDP...
+                    sendResultViaUDP(calculateResult(number1, number2, calculation_Method), remoteAddress, iUDPResultReceivingPort);
+                }
+            }
+        } catch (IOException e) {
+            System.err.println("Problem with TcpExample3Server 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!");
+            }
+        }
+    }
+    
+    /**
+     * send the result to Bernd 10x
+     * @param result
+     * @param inetAddress Bernd's IP
+     * @param port Bernd's UDP port number
+     * @throws IOException 
+     */
+    private static void sendResultViaUDP(float result, InetAddress inetAddress, int port) throws IOException{
+        DatagramSocket udpSocket = null;
+        DataOutputStream  dos = null;
+        
+        try
+        {
+            // Create a UDP socket
+            udpSocket = new DatagramSocket(); // let system assign output port, then SENDING_PORT not needed
+            
+            // Put together a message with binary content. "ByteArrayOutputStream"
+            // is a java.io utility that lets us put together an array of binary
+            // data, which we put into the UDP packet.
+            
+            ByteArrayOutputStream baos = new ByteArrayOutputStream(1500); // how many bytes are in buffer?  MTU=1500 is good
+            dos = new DataOutputStream(baos); // wrapper for writing values, connects both streams
+			
+            // Put together a packet to send
+            // these types and order of variables must match on sender and receiver
+            byte[] byteArray = baos.toByteArray();
+            
+            DatagramPacket datagramPacket = new DatagramPacket(byteArray, byteArray.length, inetAddress, port);
+       
+            for (int index = 1; index <= 10; index++) 
+            {
+                dos.writeFloat  (result);
+                dos.flush(); // sends DataOutputStream to ByteArrayOutputStream
+                byteArray = baos.toByteArray();    // OK so go get the flushed result...
+                datagramPacket.setData(byteArray); // and put it in the packet...
+                udpSocket.send(datagramPacket);    // and send it away. boom gone, nonblocking.
+            
+                Thread.sleep(1000); // Send packets at rate of one per second
+                baos.reset(); // clear the output stream after sending
+            }
+            dos.close();
+        }
+        catch (IOException | InterruptedException e)
+        {
+            System.err.println("Problem with UdpSender, see exception trace:");
+            System.err.println(e);
+        } 
+        finally // clean up prior to exit, don't want to leave behind zombies
+        {
+            if (udpSocket != null)
+                udpSocket.close();
+            
+            if (dos != null)
+                dos.close();
+        }
+    }
+    
+    /**
+     * calculates the result based on given numbers and operator
+     * @param n1 first number
+     * @param n2 second number
+     * @param operator
+     * @return the result as a float
+     */
+    private static float calculateResult(int n1, int n2, String operator){
+        float result = -1;
+        switch (operator) {
+            case "+":
+                result = n1 + n2;
+                break;
+            case "-":
+                result = n1 - n2;
+                break;
+            case "*":
+                result = n1 * n2;
+                break;
+            case "/":
+                result = n1 / n2;
+                break;
+            default:
+                System.err.println(operator +" is not a valid operator!");
+                break;
+        }
+        return result;
+    }
+}

assignments/src/MV3500Cohort2020JulySeptember/homework3/Mahan/MahanUdpReceiver.java

+package MV3500Cohort2020JulySeptember.homework3.Mahan;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ *
+ * @author Bill
+ */
+public class MahanUdpReceiver 
+{
+//  public static final int       SENDING_PORT = 1414; // port used by UdpSender, unneeded here
+    public static final int     RECEIVING_PORT = 1415;
+    public static final String DESINATION_HOST = "10.1.105.12";
+
+    /**
+     * @param args the command line arguments
+     * @throws java.io.IOException
+     */
+    public static void main(String[] args) throws IOException 
+    {
+        DatagramSocket udpSocket = null;
+        
+        try
+        {
+            System.out.println(MahanUdpReceiver.class.getName() + " started...");
+            
+            // Create a UDP socket
+            udpSocket = new DatagramSocket(RECEIVING_PORT);
+            udpSocket.setReceiveBufferSize(1500); // how many bytes are in buffer?  MTU=1500 is good
+            udpSocket.setBroadcast(false);        // we're just receiving here
+            
+            byte[] byteArray = new byte[1500];
+            DatagramPacket receivePacket = new DatagramPacket(byteArray, byteArray.length);
+            
+            ByteArrayInputStream bais = new ByteArrayInputStream(byteArray);
+            DataInputStream dis = new DataInputStream(bais);
+            
+            boolean       isEvenParity;
+            int           packetCount = 0;
+            int           firstInt;   
+            float         secondFloat;
+            String        thirdString;
+            String        padding;
+            
+            // You need a new receiving packet to read from every packet received
+            while (true)
+            {
+                packetCount++; // good practice to increment counter at start of loop, when possible
+                udpSocket.receive(receivePacket); // blocks until packet is received
+                
+                // values of interest follow. order and types of what was sent must match what you are reading!
+                firstInt     = dis.readInt();     // packetID
+                secondFloat  = dis.readFloat();
+                thirdString  = dis.readUTF();     // string value with guaranteed encoding, matches UTF-8 is 8 bit
+                isEvenParity = dis.readBoolean(); // ok, we've gotten everything we're looking for.  
+                
+                dis.reset(); // now clear the input stream after reading, in preparation for next loop
+                
+                if  (isEvenParity) 
+                     padding = " ";
+                else padding = "";
+                
+                System.out.println("[" + MahanUdpReceiver.class.getName() + "]" + 
+                                               " packetID="   + firstInt +            // have output message use same name as sender
+                                     ", second float value="   + secondFloat  + 
+                                     ", third String value=\"" + thirdString  + "\"" + // note that /" is literal quote character
+                                    " isPacketIdEvenParity="   + isEvenParity + ","  + padding +
+                                     " packet counter="        + packetCount);
+            }
+        }
+        catch(IOException e)
+        {
+            System.err.println("Problem with UdpReceiver, see exception trace:");
+            System.err.println(e);
+        } 
+        finally // clean up prior to exit, don't want to leave behind zombie socket
+        {
+            if (udpSocket != null)
+                udpSocket.close();
+            System.out.println(MahanUdpReceiver.class.getName() + " complete."); // all done
+        }
+    }
+}

assignments/src/MV3500Cohort2020JulySeptember/homework3/Mahan/MahanUdpSender.java

+package MV3500Cohort2020JulySeptember.homework3.Mahan;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ *
+ * @author Bill
+ */
+public class MahanUdpSender
+{
+    // System properties: https://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html
+    public static final String            MY_NAME = System.getProperty("user.name"); // guru incantation   8)
+//  public static final int          SENDING_PORT = 1414; // not needed, can let system choose an open local port
+    public static final int        RECEIVING_PORT = 1415;
+    public static final int TOTAL_PACKETS_TO_SEND = 100;
+    
+    // here is what we need for lab comms
+    public static final String   DESTINATION_HOST = "10.1.105.12"; // localhost 127.0.0.1 or argon 10.1.105.1 or 10.1.105.1 or whatever
+    
+    @SuppressWarnings("SleepWhileInLoop")
+    public static void main(String[] args) throws IOException 
+    {
+        DatagramSocket udpSocket = null;
+        DataOutputStream  dos = null;
+        int   packetID = 0;     // counter variable to send in packet
+        float    value = -1.0f; // unreachable value is good sentinel to ensure expected changes occur
+        String message = MY_NAME + " says I see you Chris"; // no really
+        String padding = new String();
+        
+        try
+        {
+            System.out.println(MahanUdpSender.class.getName() + " shows how to send simple-type values via DataOutputStream");
+            System.out.println(MahanUdpSender.class.getName() + " started...");
+            
+            // Create a UDP socket
+            udpSocket = new DatagramSocket(); // let system assign output port, then SENDING_PORT not needed
+            
+            // Put together a message with binary content. "ByteArrayOutputStream"
+            // is a java.io utility that lets us put together an array of binary
+            // data, which we put into the UDP packet.
+            
+            ByteArrayOutputStream baos = new ByteArrayOutputStream(1500); // how many bytes are in buffer?  MTU=1500 is good
+            dos = new DataOutputStream(baos); // wrapper for writing values, connects both streams
+			
+            // Put together a packet to send
+            // these types and order of variables must match on sender and receiver
+            byte[] byteArray = baos.toByteArray();
+            
+            // ID of the host we are sending to
+            InetAddress destinationAddress = InetAddress.getByName(DESTINATION_HOST);
+            // ID of the host we are sending from
+            InetAddress      sourceAddress = InetAddress.getByName("localhost"); // possibly identical if source not modified
+            
+            DatagramPacket datagramPacket = new DatagramPacket(byteArray, byteArray.length, destinationAddress, RECEIVING_PORT);
+       
+            // Hmmm, how fast does UDP stream go? Does UDP effectively slow packets down, or does
+            // this cause network problems? (hint: yes for an unlimited send rate, unlike TCP).
+            // How do you know on the receiving side that you haven't received a
+            // duplicate UDP packet, out-of-order packet, or dropped packet? your responsibility.
+            
+            for (int index = 1; index <= TOTAL_PACKETS_TO_SEND; index++) // avoid infinite send loops in code, they can be hard to kill!
+            {
+                packetID++;                               // increment counter, prefer using explicit value to index
+                value = TOTAL_PACKETS_TO_SEND - packetID; // countdown
+                boolean isPacketIdEvenParity = ((packetID % 2) == 0); // % is modulo operator; result 0 is even parity, 1 is odd parity
+                
+                // values of interest follow. order and types of what was sent must match what you are reading!
+                dos.writeInt    (packetID);
+                dos.writeFloat  (value);
+                dos.writeUTF    (message); // string value with guaranteed encoding, matches UTF-8 is 8 bit
+                dos.writeBoolean(isPacketIdEvenParity);
+                
+                dos.flush(); // sends DataOutputStream to ByteArrayOutputStream
+                byteArray = baos.toByteArray();    // OK so go get the flushed result...
+                datagramPacket.setData(byteArray); // and put it in the packet...
+                udpSocket.send(datagramPacket);    // and send it away. boom gone, nonblocking.
+//              System.out.println("udpSocket output port=" + udpSocket.getLocalPort()); // diagnostic tells what port was chosen by system
+                
+                if  (isPacketIdEvenParity)
+                     padding = " ";
+                else padding = "";
+            
+                Thread.sleep(1000); // Send packets at rate of one per second
+                System.out.println("[" + MahanUdpSender.class.getName() + "] " + MY_NAME + " " + sourceAddress + 
+                                   " sent values(" + packetID + "," + value + ",\"" + message + "\"," + isPacketIdEvenParity +
+                                   ")" + padding + " as packet #" + index + " of " + TOTAL_PACKETS_TO_SEND);
+                baos.reset(); // clear the output stream after sending
+            }
+        }
+        catch (IOException | InterruptedException e)
+        {
+            System.err.println("Problem with UdpSender, see exception trace:");
+            System.err.println(e);
+        } 
+        finally // clean up prior to exit, don't want to leave behind zombies
+        {
+            if (udpSocket != null)
+                udpSocket.close();
+            
+            if (dos != null)
+                dos.close();
+            System.out.println(MahanUdpSender.class.getName() + " complete."); // all done
+        }
+    }
+}

assignments/src/MV3500Cohort2020JulySeptember/homework3/Weissenberger/README.md

@@ -10,3 +10,30 @@ References include
 * [assignments source subdirectories](../../../../../assignments/src) show examples from previous cohorts. 
 
 Questions and innovation are always welcome, good luck!
+
+
+
+**************************************************
+Project for HW #3
+Team: "Germany" (Stefan and Bernd) 
+**************************************************
+
+
+
+This program(s) do(es) the following:
+- send two numbers, a mathematical operator and a port number over VPN to a TCP receiver
+- the TCP receiver calculates the result and send it back to the sender over VPN using UDP!
+- the UDP receiver shows the result
+
+The main focus was to send via TCP over a VPN, do something and send the result back via UDP.
+
+How to run the project:
+0. connect both computer with the argon net
+1. run UDPResultReceiver on Bernd's computer
+2. run TCPNumberReceiverUDPResultSender on Stefan's computer
+3. find Stefan's IP within the argon net
+4. change the TCP_ARGON_SERVER_IP in class TCPNumberSender to Stefan's IP.
+5. run TCPNumberSender
+
+(you can edit the numbers and run TCPNumberSender multiple times...)
+

assignments/src/MV3500Cohort2020JulySeptember/homework3/Weissenberger/TCPNumberSender.java

+
+package MV3500Cohort2020JulySeptember.homework3.Weissenberger;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.net.Socket;
+
+/**
+ * This class will connect to an TCP receiver over VPN (argon) and send 
+ * two numbers
+ * @date 08/17/2020
+ * @author Loki
+ * @group Weissenberger/Goericke
+ */
+public class TCPNumberSender {
+    
+    // Change this to the IP address of the TCP server 10.1.105.9 (127.0.0.1 just for testing)
+    private static final String TCP_ARGON_SERVER_IP = "127.0.0.1";
+    // Change this to the port where the TCP server is listening
+    private static final int TCP_ARGON_SERVER_PORT = 2317;
+    // Where the result should be posted (port)
+    private static final int UDP_ARGON_RECEIVING_PORT = 1415;
+    
+    private static final int NUMBER1 = 16;
+    private static final int NUMBER2 = 2;
+    private static final String CALCULATION_METHOD = "-";
+    
+    // how many times should the number being sent
+    private static final int REPETITION = 1;
+    private static int counter = 0;
+    
+    public static void main(String[] args) throws InterruptedException {
+        
+        // Local variables
+        Socket socket;
+        OutputStream outputStream;
+        PrintStream printStream;
+        
+        try {
+            while (counter < REPETITION){
+                // increment the counter
+                counter++;
+                System.out.println("Homwork 3: TcpNumberSender creating socket over VPN...");
+
+                // We request an IP to connect to "TCP_ARGON_SERVER_IP" over 
+                // the argon VPN and port number at that IP "TCP_ARGON_SERVER_PORT". 
+                // This establishes a connection to that IP in the form of a Socket
+                // object.
+                socket = new Socket(TCP_ARGON_SERVER_IP, TCP_ARGON_SERVER_PORT); // locohost?
+
+                
+                // instanciate the streams:
+                outputStream = socket.getOutputStream();
+                printStream = new PrintStream(outputStream);
+                // send a first text to server
+                printStream.println("This is message from client.");
+                printStream.flush();
+                // wait 1 second
+                Thread.sleep(1000);   
+                
+                // sending number 1
+                printStream.println(NUMBER1);
+                // sending number 2
+                printStream.println(NUMBER2);
+                // sending calc method
+                printStream.println(CALCULATION_METHOD);
+                // sending the port where the result should be send to
+                printStream.println(UDP_ARGON_RECEIVING_PORT);
+                printStream.flush();
+                // wait 1 second
+                Thread.sleep(1000);   
+                
+                System.out.println("==================================================");
+                System.out.println(NUMBER1+" and "+NUMBER2+" were sent to server. Calculating method was: "+CALCULATION_METHOD);
+                
+                // close TCP socket to server
+                socket.close();
+            } // end while(true)
+        } 
+        catch (IOException e)
+        {
+            System.err.println("Problem with TCPNumberSender networking:");
+            System.err.println("Error: " + e);
+            
+            if (e instanceof java.net.BindException) {
+                System.err.println("*** Be sure to stop any other running instances of programs using this port: "+TCP_ARGON_SERVER_PORT);
+            }
+        }
+        finally // occurs after any other activity when shutting down
+        {
+            System.out.println();
+            System.out.println("TCPNumberSender exit");
+        }
+    }
+
+}

assignments/src/MV3500Cohort2020JulySeptember/homework3/Weissenberger/UDPResultReceiver.java

+
+package MV3500Cohort2020JulySeptember.homework3.Weissenberger;
+
+import java.io.ByteArrayInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+
+/**
+ * This class will be connected by an UDP sender over VPN (argon) 
+ * @date 08/17/2020
+ * @author Loki
+ * @group Weissenberger/Goericke
+ */
+public class UDPResultReceiver {
+
+    public static final int    RECEIVING_PORT = 1415;
+
+    /**
+     * @param args the command line arguments
+     * @throws java.io.IOException
+     */
+    public static void main(String[] args) throws IOException 
+    {
+        DatagramSocket udpSocket = null;
+        
+        try
+        {
+            System.out.println(UDPResultReceiver.class.getName() + " started...");
+            
+            // Create a UDP socket
+            udpSocket = new DatagramSocket(RECEIVING_PORT);
+            udpSocket.setReceiveBufferSize(1500); // how many bytes are in buffer?  MTU=1500 is good
+            udpSocket.setBroadcast(false);        // we're just receiving here
+            
+            byte[] byteArray = new byte[1500];
+            DatagramPacket receivePacket = new DatagramPacket(byteArray, byteArray.length);
+            
+            ByteArrayInputStream bais = new ByteArrayInputStream(byteArray);
+            DataInputStream dis = new DataInputStream(bais);
+            
+            float result;
+            
+            // You need a new receiving packet to read from every packet received
+            while (true)
+            {
+                udpSocket.receive(receivePacket); // blocks until packet is received
+                
+                result  = dis.readFloat();
+                
+                dis.reset(); // now clear the input stream after reading, in preparation for next loop
+                
+                System.out.println("Calculated result: "+result);
+                
+            }
+        }
+        catch(IOException e)
+        {
+            System.err.println("Problem with UdpReceiver, see exception trace:");
+            System.err.println(e);
+        } 
+        finally // clean up prior to exit, don't want to leave behind zombie socket
+        {
+            if (udpSocket != null)
+                udpSocket.close();
+            System.out.println(UDPResultReceiver.class.getName() + " complete."); // all done
+        }
+    }
+
+}

examples/src/HttpServletExamples/HttpWebPageSource.java

@@ -27,9 +27,13 @@ public class HttpWebPageSource {
            
            // We request an IP to connect to a web server running on default http port 80.
            
-           String WEB_ADDRESS = "www.nps.edu";
-           System.out.println("New socket WEB_ADDRESS=" + WEB_ADDRESS);
-           Socket socket = new Socket(WEB_ADDRESS, 80); // compare alternative: https on port 443
+           String WEB_SERVER_ADDRESS    = "www.nps.edu";
+           int    WEB_SERVER_PORT_HTTP  = 80;
+           int    WEB_SERVER_PORT_HTTPS = 443; // does this work too?
+           System.out.println("New socket WEB_ADDRESS=" + WEB_SERVER_ADDRESS);
+           
+           // this Java construct will work for HTTP but not HTTPS
+           Socket socket = new Socket(WEB_SERVER_ADDRESS, WEB_SERVER_PORT_HTTPS); // compare alternative: https on port 443
            
            // we send a command to the web server, asking for what
            // we want. Note that the format for the command is very