initial commit final project

09/03/2020

assignments/src/MV3500Cohort2020JulySeptember/homework4/WeissenbergerGoericke/TCPReceiverVPNBridge.java

 
-package MV3500Cohort2020JulySeptember.homework4.Weissenberger;
+package MV3500Cohort2020JulySeptember.homework4.WeissenbergerGoericke;
 
 import java.io.IOException;
 import java.io.OutputStream;

assignments/src/MV3500Cohort2020JulySeptember/homework4/WeissenbergerGoericke/TcpServerForFinal.java

-package MV3500Cohort2020JulySeptember.homework4.Weissenberger;
+package MV3500Cohort2020JulySeptember.homework4.WeissenbergerGoericke;
 
 import java.io.*;
 import java.net.*;
@@ -24,6 +24,9 @@ import java.net.*;
  */
 public class TcpServerForFinal {
 
+    public static final String DEST_INET_AD = "127.0.0.1";
+    public static final String LOCAL_WIFI_INET = "192.168.188.106";
+    
     public static void main(String[] args) {
         try {
             
@@ -33,7 +36,7 @@ public class TcpServerForFinal {
             System.out.println("TcpExample3Server has started..."); // it helps debugging to put this on console first
             
             //ServerSocket serverSocket = new ServerSocket(2317);
-            InetAddress[] ia = InetAddress.getAllByName("192.168.188.106");
+            InetAddress[] ia = InetAddress.getAllByName(LOCAL_WIFI_INET);
             for (int i = 0;i < ia.length; i++){
                 System.out.println("---: "+ia[i]);
             }
@@ -78,6 +81,7 @@ public class TcpServerForFinal {
                     System.out.println("TcpExample3Server socket pair showing host name, address, port:");
                     
                 }
+                sendResultViaUDP(serverMessage);
             }
         } catch (IOException e) {
             System.err.println("Problem with TcpExample3Server networking: " + e);
@@ -88,4 +92,61 @@ public class TcpServerForFinal {
             }
         }
     }
+    
+    /**
+     * send the result to Stefan 2x
+     * @param result
+     * @param inetAddress Stefans's IP
+     * @param port Stefans's UDP port number
+     * @throws IOException 
+     */
+    private static void sendResultViaUDP(String result) 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();
+            InetAddress destinationAddress = InetAddress.getByName(DEST_INET_AD);
+            DatagramPacket datagramPacket = new DatagramPacket(byteArray, byteArray.length, destinationAddress, 1415);
+       
+            for (int index = 1; index <= 2; index++) 
+            {
+                dos.writeUTF  (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();
+        }
+    }
 }

assignments/src/MV3500Cohort2020JulySeptember/homework4/WeissenbergerGoericke/UDPResultReceiver.java

+
+package MV3500Cohort2020JulySeptember.homework4.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 09/02/2020
+ * @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);
+            
+            String received;
+            
+            // You need a new receiving packet to read from every packet received
+            while (true)
+            {
+                udpSocket.receive(receivePacket); // blocks until packet is received
+                
+                received  = dis.readUTF();
+                
+                dis.reset(); // now clear the input stream after reading, in preparation for next loop
+                
+                System.out.println("Received from Bernd: "+received);
+                
+            }
+        }
+        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
+        }
+    }
+
+}