From bc693da0dc4e6e58841e0200a9e1e838e9c79d34 Mon Sep 17 00:00:00 2001
From: leahhedgcorth <leahhedgcorth@drmi-l7410-031.ern.nps.edu>
Date: Mon, 1 May 2023 08:36:45 -0700
Subject: [PATCH] Homework 2
---
.../Hedgcorth/MulticastUdpReceiver.java | 26 +++--
.../Hedgcorth/MulticastUdpSender.java | 107 ++++++++++--------
2 files changed, 74 insertions(+), 59 deletions(-)
diff --git a/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpReceiver.java b/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpReceiver.java
index c474c486a8..1f121805b0 100644
--- a/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpReceiver.java
+++ b/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpReceiver.java
@@ -13,21 +13,23 @@ import java.util.logging.Logger;
/**
* Looks a lot like UdpReceiver. Start this before launching MulticastSender.
+ * Modified to close after sending 30 packets.
*
* @author leahhedgcorth
*/
-public class MulticastUdpReceiver
-{
- /** Default constructor */
- public MulticastUdpReceiver()
- {
+public class MulticastUdpReceiver {
+
+ /**
+ * Default constructor
+ */
+ public MulticastUdpReceiver() {
// default constructor
}
// reserved range for all IPv4 multicast: 224.0.0.0 through 239.255.255.255
// https://en.wikipedia.org/wiki/Multicast_address
// https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml
private static final String MULTICAST_ADDRESS = "239.1.2.15";
- private static final int DESTINATION_PORT = 1718;
+ private static final int DESTINATION_PORT = 1718;
/**
* Time to live: how many router-decrement levels can be crossed
@@ -39,15 +41,15 @@ public class MulticastUdpReceiver
/**
* Program invocation, execution starts here
+ *
* @param args command-line arguments
*/
- public static void main(String[] args)
- {
+ public static void main(String[] args) {
MulticastSocket multicastSocket = null;
InetSocketAddress group = null;
ByteBuffer buffer = ByteBuffer.allocate(1500);
DatagramPacket packet = new DatagramPacket(buffer.array(), buffer.capacity());
-
+
try {
System.out.println("UdpExamples.MulticastUdpReceiver started...");
@@ -61,13 +63,13 @@ public class MulticastUdpReceiver
multicastSocket = new MulticastSocket(DESTINATION_PORT);
multicastSocket.setTimeToLive(TTL);
InetAddress multicastAddress = InetAddress.getByName(MULTICAST_ADDRESS);
-
+
group = new InetSocketAddress(multicastAddress, DESTINATION_PORT);
-
+
// Join group useful on receiving side
multicastSocket.joinGroup(group, ni = DisThreadedNetworkInterface.findIpv4Interface());
// You can join multiple groups here
-
+
System.out.println("Multicast address/port: " + multicastAddress.getHostAddress() + "/" + DESTINATION_PORT);
System.out.println("Multicast packets received log:");
diff --git a/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpSender.java b/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpSender.java
index 5f11529851..f592e12224 100644
--- a/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpSender.java
+++ b/assignments/src/MV3500Cohort2023MarchJune/homework2/Hedgcorth/MulticastUdpSender.java
@@ -1,4 +1,3 @@
-
package MV3500Cohort2023MarchJune.homework2.Hedgcorth;
import edu.nps.moves.dis7.utilities.DisThreadedNetworkInterface;
@@ -14,60 +13,78 @@ import java.util.logging.Level;
import java.util.logging.Logger;
/**
- * Looks a lot like UdpSender. Start this after launching MulticastReceiver.
- *
- * Privacy note: this sender advertises your user name as part of the multicast packet message
- *
+ * Looks a lot like UdpSender. Start this after launching MulticastReceiver.
+ * Modified to close after sending 30 packets.
+ *
+ * Privacy note: this sender advertises your user name as part of the multicast
+ * packet message
+ *
*
* @author leahhedgcorth
*/
public class MulticastUdpSender {
-
- /** Default constructor */
- public MulticastUdpSender()
- {
+
+ /**
+ * Default constructor
+ */
+ public MulticastUdpSender() {
// default constructor
}
// reserved range for all IPv4 multicast: 224.0.0.0 through 239.255.255.255
// https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml
- /** Default multicast group address for send and receive connections.
- * @see <a href="https://en.wikipedia.org/wiki/Multicast_address">https://en.wikipedia.org/wiki/Multicast_address</a> */
+ /**
+ * Default multicast group address for send and receive connections.
+ *
+ * @see
+ * <a href="https://en.wikipedia.org/wiki/Multicast_address">https://en.wikipedia.org/wiki/Multicast_address</a>
+ */
public static final String MULTICAST_ADDRESS = "239.1.2.15"; // within reserved multicast address range
- /** Default socket port used, matches Wireshark DIS capture default
- * @see <a href="https://en.wikipedia.org/wiki/Port_(computer_networking)">https://en.wikipedia.org/wiki/Port_(computer_networking)</a> */
- public static final int DESTINATION_PORT = 1718;
-
- /** Time to live: how many router-decrement levels can be crossed */
+ /**
+ * Default socket port used, matches Wireshark DIS capture default
+ *
+ * @see
+ * <a href="https://en.wikipedia.org/wiki/Port_(computer_networking)">https://en.wikipedia.org/wiki/Port_(computer_networking)</a>
+ */
+ public static final int DESTINATION_PORT = 1718;
+
+ /**
+ * Time to live: how many router-decrement levels can be crossed
+ */
public static final int TTL = 10;
-
- /** How many packets to send prior to termination */
- public static final int LOOPSIZE = 20; // or maybe 20000
-
- /** Receiving this message causes termination
- * @see <a href="https://en.wikipedia.org/wiki/Sentinel_value">https://en.wikipedia.org/wiki/Sentinel_value</a> */
+
+ /**
+ * How many packets to send prior to termination
+ */
+ public static final int LOOPSIZE = 30; // or maybe 20000
+
+ /**
+ * Receiving this message causes termination
+ *
+ * @see
+ * <a href="https://en.wikipedia.org/wiki/Sentinel_value">https://en.wikipedia.org/wiki/Sentinel_value</a>
+ */
public static final String QUIT_SENTINEL = "QUIT QUIT QUIT!";
private static NetworkInterface ni;
-
+
/**
* Program invocation, execution starts here
+ *
* @param args command-line arguments
* @throws java.io.IOException execution error
*/
@SuppressWarnings("SleepWhileInLoop")
- public static void main(String[] args) throws IOException
- {
+ public static void main(String[] args) throws IOException {
MulticastSocket multicastSocket = null;
InetSocketAddress group = null;
-
+
// 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);
-
- try
- {
+ DataOutputStream dos = new DataOutputStream(baos);
+
+ try {
System.out.println("UdpExamples.MulticastUdpSender started...");
// This is a java/IPv6 problem. You should also add it to the
// arguments used to start the app, eg -Djava.net.preferIPv4Stack=true
@@ -75,35 +92,33 @@ public class MulticastUdpSender {
// netbeans must be restarted after these settings.
// https://stackoverflow.com/questions/18747134/getting-cant-assign-requested-address-java-net-socketexception-using-ehcache
System.setProperty("java.net.preferIPv4Stack", "true");
-
+
// multicast group we are sending to--not a single host
multicastSocket = new MulticastSocket(/*DESTINATION_PORT*/);
multicastSocket.setTimeToLive(TTL); // time to live reduces scope of transmission
InetAddress multicastAddress = InetAddress.getByName(MULTICAST_ADDRESS);
System.out.println("Multicast address/port: " + multicastAddress.getHostAddress() + "/" + DESTINATION_PORT);
-
+
group = new InetSocketAddress(multicastAddress, DESTINATION_PORT);
// Join group useful on receiving side
multicastSocket.joinGroup(group, ni = DisThreadedNetworkInterface.findIpv4Interface());
// You can join multiple groups here
-
+
byte[] buffer = baos.toByteArray();
DatagramPacket packet = new DatagramPacket(buffer, buffer.length, group/*, DESTINATION_PORT*/);
-
- for (int index = 0; index < LOOPSIZE; index++)
- {
+
+ for (int index = 0; index < LOOPSIZE; index++) {
// Put together an updated packet to send
- if (index < LOOPSIZE - 1)
- {
+ if (index < LOOPSIZE - 1) {
// Put together an updated packet to send
dos.writeChars("From " + System.getProperty("user.name") + ": ");
dos.writeChars("MulticastSender packet " + Integer.toString(index) + ";"); // string chars for readability
- dos.writeInt (index); // arbitrary data, needs Java or byte-alignment to read
+ dos.writeInt(index); // arbitrary data, needs Java or byte-alignment to read
dos.writeFloat(17.0f); // arbitrary data, needs Java or byte-alignment to read
dos.writeFloat(23.0f); // arbitrary data, needs Java or byte-alignment to read
+ } else {
+ dos.writeChars(QUIT_SENTINEL + ";"); // note string must include ; semicolon as termination sentinel
}
- else dos.writeChars(QUIT_SENTINEL + ";"); // note string must include ; semicolon as termination sentinel
-
buffer = baos.toByteArray();
packet.setData(buffer);
multicastSocket.send(packet);
@@ -118,13 +133,11 @@ public class MulticastUdpSender {
Thread.sleep(1000); // Send 100, one per second
}
System.out.println("MulticastSender complete.");
- }
- catch(IOException | InterruptedException e)
- {
+ } catch (IOException | InterruptedException e) {
System.err.println("Problem with MulticastSender, see exception trace:");
System.err.println(e);
} finally {
-
+
if (multicastSocket != null && !multicastSocket.isClosed()) {
try {
multicastSocket.leaveGroup(group, ni);
@@ -133,9 +146,9 @@ public class MulticastUdpSender {
}
multicastSocket.close();
}
-
+
dos.close();
}
}
-
+
}
--
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