multicast example

projects/multicastExample1/MulticastSenderExample/nbproject/genfiles.properties

+build.xml.data.CRC32=d1f74d73
+build.xml.script.CRC32=894241e6
+build.xml.stylesheet.CRC32=8064a381@1.80.1.48
+# This file is used by a NetBeans-based IDE to track changes in generated files such as build-impl.xml.
+# Do not edit this file. You may delete it but then the IDE will never regenerate such files for you.
+nbproject/build-impl.xml.data.CRC32=d1f74d73
+nbproject/build-impl.xml.script.CRC32=46485cbc
+nbproject/build-impl.xml.stylesheet.CRC32=830a3534@1.80.1.48

projects/multicastExample1/MulticastSenderExample/nbproject/private/private.properties

+application.args=-Djava.net.preferIPv4Stack=true
+compile.on.save=true
+do.depend=false
+do.jar=true
+javac.debug=true
+javadoc.preview=true
+user.properties.file=/Users/mcgredo/Library/Application Support/NetBeans/8.2/build.properties

projects/multicastExample1/MulticastSenderExample/nbproject/private/private.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project-private xmlns="http://www.netbeans.org/ns/project-private/1">
+    <editor-bookmarks xmlns="http://www.netbeans.org/ns/editor-bookmarks/2" lastBookmarkId="0"/>
+    <open-files xmlns="http://www.netbeans.org/ns/projectui-open-files/2">
+        <group>
+            <file>file:/Users/mcgredo/projects/gitlab/NetworkedGraphicsMV3500/projects/multicastExample1/MulticastSenderExample/src/multicastsenderexample/MulticastSenderExample.java</file>
+        </group>
+    </open-files>
+</project-private>

projects/multicastExample1/MulticastSenderExample/nbproject/project.properties

+annotation.processing.enabled=true
+annotation.processing.enabled.in.editor=false
+annotation.processing.processors.list=
+annotation.processing.run.all.processors=true
+annotation.processing.source.output=${build.generated.sources.dir}/ap-source-output
+application.title=MulticastSenderExample
+application.vendor=mcgredo
+build.classes.dir=${build.dir}/classes
+build.classes.excludes=**/*.java,**/*.form
+# This directory is removed when the project is cleaned:
+build.dir=build
+build.generated.dir=${build.dir}/generated
+build.generated.sources.dir=${build.dir}/generated-sources
+# Only compile against the classpath explicitly listed here:
+build.sysclasspath=ignore
+build.test.classes.dir=${build.dir}/test/classes
+build.test.results.dir=${build.dir}/test/results
+# Uncomment to specify the preferred debugger connection transport:
+#debug.transport=dt_socket
+debug.classpath=\
+    ${run.classpath}
+debug.test.classpath=\
+    ${run.test.classpath}
+# Files in build.classes.dir which should be excluded from distribution jar
+dist.archive.excludes=
+# This directory is removed when the project is cleaned:
+dist.dir=dist
+dist.jar=${dist.dir}/MulticastSenderExample.jar
+dist.javadoc.dir=${dist.dir}/javadoc
+endorsed.classpath=
+excludes=
+includes=**
+jar.compress=false
+javac.classpath=
+# Space-separated list of extra javac options
+javac.compilerargs=
+javac.deprecation=false
+javac.external.vm=true
+javac.processorpath=\
+    ${javac.classpath}
+javac.source=1.8
+javac.target=1.8
+javac.test.classpath=\
+    ${javac.classpath}:\
+    ${build.classes.dir}
+javac.test.processorpath=\
+    ${javac.test.classpath}
+javadoc.additionalparam=
+javadoc.author=false
+javadoc.encoding=${source.encoding}
+javadoc.noindex=false
+javadoc.nonavbar=false
+javadoc.notree=false
+javadoc.private=false
+javadoc.splitindex=true
+javadoc.use=true
+javadoc.version=false
+javadoc.windowtitle=
+main.class=multicastsenderexample.MulticastSenderExample
+manifest.file=manifest.mf
+meta.inf.dir=${src.dir}/META-INF
+mkdist.disabled=false
+platform.active=default_platform
+run.classpath=\
+    ${javac.classpath}:\
+    ${build.classes.dir}
+# Space-separated list of JVM arguments used when running the project.
+# You may also define separate properties like run-sys-prop.name=value instead of -Dname=value.
+# To set system properties for unit tests define test-sys-prop.name=value:
+run.jvmargs=
+run.test.classpath=\
+    ${javac.test.classpath}:\
+    ${build.test.classes.dir}
+source.encoding=UTF-8
+src.dir=src
+test.src.dir=test

projects/multicastExample1/MulticastSenderExample/nbproject/project.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://www.netbeans.org/ns/project/1">
+    <type>org.netbeans.modules.java.j2seproject</type>
+    <configuration>
+        <data xmlns="http://www.netbeans.org/ns/j2se-project/3">
+            <name>MulticastSenderExample</name>
+            <source-roots>
+                <root id="src.dir"/>
+            </source-roots>
+            <test-roots>
+                <root id="test.src.dir"/>
+            </test-roots>
+        </data>
+    </configuration>
+</project>

projects/multicastExample1/MulticastSenderExample/src/multicastsenderexample/MulticastSenderExample.java

+
+package multicastsenderexample;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * Looks a lot like a UDP sender.
+ * 
+ * @author mcgredo
+ */
+public class MulticastSenderExample {
+
+    public static final String MULTICAST_ADDRESS = "239.1.2.15";
+    public static final int DESTINATION_PORT = 1717;
+    /** How many routers can be crossed */
+    public static final int TTL = 10; 
+    
+    public static void main(String[] args) 
+    {
+        try
+        {
+            // This is a java/IPv6 problem. You should also add it to the
+            // arguments used to start the app, eg -Djava.net.preferIPv4Stack=true
+            // set in the "run" section of preferences. Also, typically
+            // 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");
+            
+            
+            MulticastSocket multicastSocket = new MulticastSocket(1718);
+            multicastSocket.setTimeToLive(TTL);
+            InetAddress multicastAddress = InetAddress.getByName(MULTICAST_ADDRESS);
+            System.out.println(multicastAddress);            
+            // Join group useful on receiving side
+            multicastSocket.joinGroup(multicastAddress);
+            // You can join multiple groups here
+            
+            // 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);
+            dos.writeFloat(17.0f);
+            dos.writeFloat(23.0f);
+            byte[] buffer = baos.toByteArray();
+            
+            // Put together a packet to send
+            
+            // muticast group we are sending to--not a single host
+            
+            DatagramPacket packet = new DatagramPacket(buffer, buffer.length, multicastAddress, DESTINATION_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 idx = 0; idx < 100; idx++)
+            {
+               multicastSocket.send(packet);
+               Thread.sleep(1000); // Send 100, one per second
+               System.out.println("Sent multicast packet " + idx + " of 100");
+            }
+        }
+        catch(Exception e)
+        {
+            System.out.println(e);
+        }
+    }
+    
+}