HW3 submission

deliverables/src/MV3500Cohort2018JulySeptember/homework3/Jackson_UdpSender.java

+package MV3500Cohort2018JulySeptember.homework3;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * An example of sending UDP packets. The sending and receiving programs
+ * use different UDP ports; there can be problems getting this to work
+ * if both the sending and receiving sockets try to use the same port
+ * on the same host.
+ * 
+ * @author mcgredo
+ */
+public class Jackson_UdpSender 
+{
+
+    public static final int      SENDING_PORT   = 1414;
+    public static final int      RECEIVING_PORT = 1415;
+    public static final String DESTINATION_HOST = "localhost";
+
+	@SuppressWarnings("SleepWhileInLoop")
+        
+    public static void main(String[] args) 
+    {
+        //int idx = 0;
+        String[] preamble = new String[10];  
+            preamble[0] = " We the People of the United States, ";
+            preamble[1] = " in Order to form a more perfect Union, ";
+            preamble[2] = " establish Justice, ";
+            preamble[3] = " insure domestic Tranquility, ";
+            preamble[4] = " provide for the common defence,";
+            preamble[5] = " promote the general Welfare, ";
+            preamble[6] = " and secure the Blessings of Liberty ";
+            preamble[7] = " to ourselves and our Posterity, ";
+            preamble[8] = " do ordain and establish this Constitution ";
+            preamble[9] = " for the United States of America."; 
+        try
+        {
+            System.out.println("UdpSender started...");
+            // Create a UDP socket
+            DatagramSocket udpSocket = new DatagramSocket(SENDING_PORT);
+            
+            // 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();
+            DataOutputStream dos = new DataOutputStream(baos);
+			// alternatives: writeFloat(17.0f); writeInt(17); writeUTF("\"hello MV3500 no really\"");
+                        
+            
+            
+            // Put together a packet to send
+            
+            // ID of the host we are sending to
+            InetAddress destinationAddress = InetAddress.getByName(DESTINATION_HOST);
+            
+            //DatagramPacket packet = new DatagramPacket(buffer, buffer.length, destinationAddress, RECEIVING_PORT );
+       
+            // How fast does this go? Does UDP try to slow it 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?
+            
+            for (int index = 1; index <= 10; index++) // avoid infinite send loops in code, they can be hard to kill!
+            {
+                dos.writeChars(preamble[index-1]);
+                byte[] buffer = baos.toByteArray();
+                DatagramPacket packet = new DatagramPacket(buffer, buffer.length, destinationAddress, RECEIVING_PORT );
+                udpSocket.send(packet);
+                Thread.sleep(100); // Send 100, one per second
+                System.out.println("Sent packet " + index + " of 10");
+                
+            }
+            System.out.println("UdpSender complete.");
+        }
+        catch (IOException | InterruptedException e)
+        {
+            System.out.println("Problem with UdpSender, see exception trace:");
+            System.out.println(e);
+        }
+    }
+}