1 files changed, 73 insertions, 0 deletions
diff --git a/src/main/java/derms/replica/replica1/Announcer.java b/src/main/java/derms/replica/replica1/Announcer.java
new file mode 100644
index 0000000..e9dedc4
--- /dev/null
+++ b/src/main/java/derms/replica/replica1/Announcer.java
@@ -0,0 +1,73 @@
+package derms.replica.replica1;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.MulticastSocket;
+import java.net.NetworkInterface;
+import java.net.SocketAddress;
+import java.util.logging.Logger;
+
+public class Announcer implements Runnable {
+	public static final long intervalMillis = 3000;
+
+	private SocketAddress group;
+	private InetAddress localAddr;
+	private City city;
+	private Logger log;
+
+	public Announcer(SocketAddress group, InetAddress localAddr, City city) throws IOException {
+		this.group = group;
+		this.localAddr = localAddr;
+		this.city = city;
+		this.log = DermsLogger.getLogger(this.getClass());
+	}
+
+	@Override
+	public void run() {
+		NetworkInterface netInterface = null;
+		try {
+			netInterface = NetworkInterface.getByInetAddress(localAddr);
+			if (netInterface == null) {
+				throw new Exception("netInterface is null");
+			}
+		} catch (Exception e) {
+			log.severe("Failed to get network interface bound to "+localAddr.toString()+": "+e.getMessage());
+			return;
+		}
+
+		MulticastSocket sock = null;
+		try {
+			sock = new MulticastSocket();
+			sock.joinGroup(group, netInterface);
+		} catch (Exception e) {
+			log.severe("Failed to open multicast socket: "+e.getMessage());
+			return;
+		}
+
+		log.info("Announcing from "+localAddr.toString()+" ("+netInterface.getName()+") to "+group.toString());
+
+		DatagramPacket pkt = null;
+		try {
+			pkt = ObjectPacket.create(city, group);
+		} catch (IOException e) {
+			log.severe("Failed to create packet: "+e.getMessage());
+			sock.close();
+			return;
+		}
+
+		try {
+			for (;;) {
+				sock.send(pkt);
+				Thread.sleep(intervalMillis);
+			}
+		} catch (IOException e) {
+			log.severe("Failed to send to multicast socket "+group.toString()+": "+e.getMessage());
+		} catch (InterruptedException e) {
+			log.info("Interrupted.");
+		} finally {
+			log.info("Shutting down...");
+			sock.close();
+		}
+	}
+}
+\ No newline at end of file