From 37420659f8e977b8488105dafced25335be7d23c Mon Sep 17 00:00:00 2001
From: brutzman <brutzman@nps.edu>
Date: Sat, 14 Aug 2021 17:31:21 -0700
Subject: [PATCH] improved handling of networkInterface
---
.../src/OpenDis7Examples/AllPduReceiver.java | 165 +++++++++---------
.../src/OpenDis7Examples/AllPduSender.java | 33 ++--
2 files changed, 108 insertions(+), 90 deletions(-)
diff --git a/examples/src/OpenDis7Examples/AllPduReceiver.java b/examples/src/OpenDis7Examples/AllPduReceiver.java
index d413c2779a..8266f78b42 100644
--- a/examples/src/OpenDis7Examples/AllPduReceiver.java
+++ b/examples/src/OpenDis7Examples/AllPduReceiver.java
@@ -23,99 +23,106 @@ public class AllPduReceiver
/** Output prefix to identify this class */
private final static String TRACE_PREFIX = "[" + AllPduReceiver.class.getName() + "] ";
- /**
+ /**
* Program invocation, execution starts here
* @param args command-line arguments
*/
public static void main(String args[])
- {
- MulticastSocket multicastSocket;
- InetAddress internetAddress;
- PduFactory pduFactory = new PduFactory();
+ {
+ MulticastSocket multicastSocket;
+ InetAddress multicastInetAddress;
+ PduFactory pduFactory = new PduFactory();
- System.out.println(TRACE_PREFIX + "started...");
+ System.out.println(TRACE_PREFIX + "started...");
- try {
- if (args.length == 2)
- {
- internetAddress = InetAddress.getByName(args[0]);
- multicastSocket = new MulticastSocket(Integer.parseInt(args[1]));
- }
- else
- {
- System.out.println("Usage: AllPduReceiver <multicast group> <port>");
- System.out.println("Default: AllPduReceiver " + DEFAULT_MULTICAST_ADDRESS + " " + DEFAULT_MULTICAST_PORT);
- multicastSocket = new MulticastSocket(DEFAULT_MULTICAST_PORT);
- internetAddress = InetAddress.getByName(DEFAULT_MULTICAST_ADDRESS);
- }
- System.out.println("To quit: stop or kill this process");
- multicastSocket.joinGroup(internetAddress);
+ try {
+ if (args.length == 2)
+ {
+ multicastInetAddress = InetAddress.getByName(args[0]);
+ multicastSocket = new MulticastSocket(Integer.parseInt(args[1]));
+ }
+ else
+ {
+ System.out.println("Usage: AllPduReceiver <multicast group> <port>");
+ System.out.println("Default: AllPduReceiver " + DEFAULT_MULTICAST_ADDRESS + " " + DEFAULT_MULTICAST_PORT);
+ multicastSocket = new MulticastSocket(DEFAULT_MULTICAST_PORT);
+ multicastInetAddress = InetAddress.getByName(DEFAULT_MULTICAST_ADDRESS);
+ }
+ System.out.println("To quit: stop or kill this process");
+ // multicastSocket.joinGroup(multicastInetAddress); // deprecated
+
+ // =======================================================================
+ // new approach using interface
+ NetworkInterface networkInterface = NetworkInterface.getByInetAddress(multicastInetAddress);
+ SocketAddress localMulticastSocketAddress = new InetSocketAddress(multicastInetAddress, DEFAULT_MULTICAST_PORT);
+ multicastSocket.joinGroup(localMulticastSocketAddress, networkInterface);
+ // =======================================================================
- byte buffer[] = new byte[1500]; // typical MTU size in bytes
-
- while (true) // Loop infinitely, receiving datagrams
- {
- Arrays.fill(buffer, (byte)0);
- DatagramPacket datagramPacket = new DatagramPacket(buffer, buffer.length); // reset packet each time
- multicastSocket.receive(datagramPacket); // process blocks here until receipt of network packet with PDU
-// datagramPacket.setLength(buffer.length);
+ byte buffer[] = new byte[1500]; // typical MTU size in bytes
-// Pdu pdu = pduFactory.createPdu(packet.getData()); // packet.getData() returns byte[] array data buffer
+ while (true) // Loop indefinitely, receiving datagrams
+ {
+ Arrays.fill(buffer, (byte)0);
+ DatagramPacket datagramPacket = new DatagramPacket(buffer, buffer.length); // reset packet each time
+ multicastSocket.receive(datagramPacket); // process blocks here until receipt of network packet with PDU
+ // datagramPacket.setLength(buffer.length);
- List<Pdu> pduBundle = pduFactory.getPdusFromBundle(datagramPacket.getData(),datagramPacket.getLength());
-
- if (pduBundle.isEmpty())
- System.out.println("Received PDU bundle is empty, packet.getData().length=" + datagramPacket.getData().length + ", error...");
-// else if (pduBundle.size() == 1)// common case, typically unremarkable
-// System.out.println("Received PDU bundle size is " + pduBundle.size());
- else if (pduBundle.size() > 1)
- System.out.println("Received PDU bundle size is " + pduBundle.size());
+ // Pdu pdu = pduFactory.createPdu(packet.getData()); // packet.getData() returns byte[] array data buffer
- for (Pdu nextPdu : pduBundle) // iterator loop through PDU bundle
- {
- DisPduType currentPduType = nextPdu.getPduType(); //short currentPduType = nextPdu.getPduType();
- String currentPduTypeName = nextPdu.getClass().getName();
- String currentPduFamilyName = nextPdu.getClass().getSuperclass().getSimpleName();
- DISProtocolFamily currentProtocolFamilyID = nextPdu.getProtocolFamily(); //short currentProtocolFamilyID = nextPdu.getProtocolFamily();
-
- StringBuilder message = new StringBuilder();
- message.append(DisTime.timeStampToString(nextPdu.getTimestamp())).append(" ");
- message.append("received new DIS PDU ");
- String currentPduTypePadded = String.format("%-48s", currentPduType); // - indicates right padding of whitespace
- message.append(currentPduTypePadded);
- // optional, verbose
-// String currentPduTypeNamePadded = String.format("%-49s", currentPduTypeName); // - indicates right padding of whitespace
-// message.append(" of type ").append(currentPduTypeNamePadded); // package.class name
- message.append(" (").append(currentProtocolFamilyID);
-// message.append(" ").append(currentPduFamilyName); // class name is also available
- message.append(")");
- System.out.println(message.toString()); // diagnostic information helps
+ List<Pdu> pduBundle = pduFactory.getPdusFromBundle(datagramPacket.getData(),datagramPacket.getLength());
- // additional message information of interest, if any
- switch (currentPduType) // using enumeration values from edu.​nps.​moves.​dis7.​enumerations.​DisPduType
- {
- case COMMENT:
- CommentPdu commentPdu = (CommentPdu)nextPdu; // cast to precise type
- ArrayList<VariableDatum> payloadList = (ArrayList)commentPdu.getVariableDatums();
- if (!payloadList.isEmpty())
- System.out.print (" messages: ");
- for (VariableDatum variableDatum : payloadList)
+ if (pduBundle.isEmpty())
+ System.out.println("Received PDU bundle is empty, packet.getData().length=" + datagramPacket.getData().length + ", error...");
+ // else if (pduBundle.size() == 1)// common case, typically unremarkable
+ // System.out.println("Received PDU bundle size is " + pduBundle.size());
+ else if (pduBundle.size() > 1)
+ System.out.println("Received PDU bundle size is " + pduBundle.size());
+
+ for (Pdu nextPdu : pduBundle) // iterator loop through PDU bundle
+ {
+ DisPduType currentPduType = nextPdu.getPduType(); //short currentPduType = nextPdu.getPduType();
+ String currentPduTypeName = nextPdu.getClass().getName();
+ String currentPduFamilyName = nextPdu.getClass().getSuperclass().getSimpleName();
+ DISProtocolFamily currentProtocolFamilyID = nextPdu.getProtocolFamily(); //short currentProtocolFamilyID = nextPdu.getProtocolFamily();
+
+ StringBuilder message = new StringBuilder();
+ message.append(DisTime.timeStampToString(nextPdu.getTimestamp())).append(" ");
+ message.append("received new DIS PDU ");
+ String currentPduTypePadded = String.format("%-48s", currentPduType); // - indicates right padding of whitespace
+ message.append(currentPduTypePadded);
+ // optional, verbose
+ // String currentPduTypeNamePadded = String.format("%-49s", currentPduTypeName); // - indicates right padding of whitespace
+ // message.append(" of type ").append(currentPduTypeNamePadded); // package.class name
+ message.append(" (").append(currentProtocolFamilyID);
+ // message.append(" ").append(currentPduFamilyName); // class name is also available
+ message.append(")");
+ System.out.println(message.toString()); // diagnostic information helps
+
+ // additional message information of interest, if any
+ switch (currentPduType) // using enumeration values from edu.​nps.​moves.​dis7.​enumerations.​DisPduType
{
- String nextComment = new String(variableDatum.getVariableDatumValue()); // convert byte[] to String
- System.out.print (" \"" + nextComment + "\"");
+ case COMMENT:
+ CommentPdu commentPdu = (CommentPdu)nextPdu; // cast to precise type
+ ArrayList<VariableDatum> payloadList = (ArrayList)commentPdu.getVariableDatums();
+ if (!payloadList.isEmpty())
+ System.out.print (" messages: ");
+ for (VariableDatum variableDatum : payloadList)
+ {
+ String nextComment = new String(variableDatum.getVariableDatumValue()); // convert byte[] to String
+ System.out.print (" \"" + nextComment + "\"");
+ }
+ System.out.println();
}
- System.out.println();
+ }
+ pduBundle.clear();
}
}
- pduBundle.clear();
+ catch (IOException e) {
+ System.out.println("Problem with OpenDis7Examples.AllPduReceiver, see exception trace:");
+ System.out.println(e);
+ }
+ finally {
+ System.out.println("OpenDis7Examples.AllPduReceiver complete.");
+ }
}
- }
- catch (IOException e) {
- System.out.println("Problem with OpenDis7Examples.AllPduReceiver, see exception trace:");
- System.out.println(e);
- }
- finally {
- System.out.println("OpenDis7Examples.AllPduReceiver complete.");
- }
- }
}
diff --git a/examples/src/OpenDis7Examples/AllPduSender.java b/examples/src/OpenDis7Examples/AllPduSender.java
index aa4d339e6d..1485b3cba8 100755
--- a/examples/src/OpenDis7Examples/AllPduSender.java
+++ b/examples/src/OpenDis7Examples/AllPduSender.java
@@ -32,7 +32,7 @@ public class AllPduSender
* Putting any upper limit on # packets sent avoids possibility of non-terminating infinite loops that continue sending packets. */
private int SEND_LOOPS_TO_PERFORM = 1;
- private static InetAddress multicastAddress;
+ private static InetAddress multicastInetAddress;
private static int port;
/** Object constructor
@@ -43,8 +43,8 @@ public class AllPduSender
this.port = DEFAULT_MULTICAST_PORT;
try
{
- multicastAddress = InetAddress.getByName(newMulticastAddress);
- if (!multicastAddress.isMulticastAddress())
+ multicastInetAddress = InetAddress.getByName(newMulticastAddress);
+ if (!multicastInetAddress.isMulticastAddress())
{
System.out.println("Not a multicast address: " + newMulticastAddress);
}
@@ -453,13 +453,24 @@ public class AllPduSender
// Send the PDUs we created
System.out.println("Send the " + generatedPdusList.size() + " PDUs we created...");
- InetAddress localMulticastAddress = InetAddress.getByName(DEFAULT_MULTICAST_ADDRESS);
+ // =======================================================================
+ // prior appproach
+// InetAddress localMulticastAddress = InetAddress.getByName(DEFAULT_MULTICAST_ADDRESS);
+// MulticastSocket multicastSocket = new MulticastSocket(DEFAULT_MULTICAST_PORT);
+// if (!localMulticastAddress.isMulticastAddress())
+// {
+// throw new RuntimeException("*** Error: sending to multicast address, but destination address " + localMulticastAddress.toString() + "is not multicast");
+// }
+// multicastSocket.joinGroup(localMulticastAddress); // deprecated
+ // =======================================================================
+ // updated approach using NetworkInterface
+ NetworkInterface networkInterface = NetworkInterface.getByInetAddress(multicastInetAddress);
+ if (networkInterface != null)
+ System.out.println("networkInterface=" + networkInterface.getDisplayName()); // typically null if loopback
+ SocketAddress localMulticastSocketAddress = new InetSocketAddress(multicastInetAddress, DEFAULT_MULTICAST_PORT);
MulticastSocket multicastSocket = new MulticastSocket(DEFAULT_MULTICAST_PORT);
- if (!localMulticastAddress.isMulticastAddress())
- {
- throw new RuntimeException("*** Error: sending to multicast address, but destination address " + localMulticastAddress.toString() + "is not multicast");
- }
- multicastSocket.joinGroup(localMulticastAddress);
+ multicastSocket.joinGroup(localMulticastSocketAddress, networkInterface);
+ // =======================================================================
byte[] buffer;
Pdu aPdu;
@@ -477,7 +488,7 @@ public class AllPduSender
aPdu.marshal(dos); // dos is DataOutputStream connected to ByteArrayOutputStrea
buffer = baos.toByteArray();
- packet = new DatagramPacket(buffer, buffer.length, localMulticastAddress, DEFAULT_MULTICAST_PORT);
+ packet = new DatagramPacket(buffer, buffer.length, multicastInetAddress, DEFAULT_MULTICAST_PORT);
multicastSocket.send(packet);
DisPduType disPduType= aPdu.getPduType();
@@ -526,7 +537,7 @@ public class AllPduSender
if (args.length == 2)
{
System.out.println("Usage: AllPduSender <multicast group> <port>");
- System.out.println("Actual: AllPduSender " + multicastAddress.getHostAddress() + " " + port);
+ System.out.println("Actual: AllPduSender " + multicastInetAddress.getHostAddress() + " " + port);
allPduSender = new AllPduSender(args[0], Integer.parseInt(args[1]));
}
else
--
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