Add Broadcaster for non-Android Java.

1 files changed, 77 insertions, 0 deletions

diff --git a/jsonrpc/src/main/java/com/orbekk/net/Broadcaster.java b/jsonrpc/src/main/java/com/orbekk/net/Broadcaster.java
new file mode 100644
index 0000000..95e279c
--- /dev/null
+++ b/jsonrpc/src/main/java/com/orbekk/net/Broadcaster.java
@@ -0,0 +1,77 @@
+package com.orbekk.net;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.InterfaceAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Enumeration;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+public class Broadcaster {
+    private Logger logger = LoggerFactory.getLogger(getClass());
+    
+    public List<InetAddress> getBroadcastAddresses() {
+        List<InetAddress> broadcastAddresses = new LinkedList<InetAddress>();
+        
+        Enumeration<NetworkInterface> interfaces;
+        try {
+            interfaces = NetworkInterface.getNetworkInterfaces();
+        } catch (SocketException e) {
+            logger.warn("Network problem?", e.fillInStackTrace());
+            return broadcastAddresses;
+        }
+        while (interfaces.hasMoreElements()) {
+            NetworkInterface iface = interfaces.nextElement();
+            try {
+                if (iface.isLoopback()) {
+                    logger.debug("Ignoring looback device " + iface.getName());
+                    continue;
+                }
+                for (InterfaceAddress address : iface.getInterfaceAddresses()) {
+                    InetAddress broadcast = address.getBroadcast();
+                    if (broadcast != null) {
+                        broadcastAddresses.add(broadcast);
+                    }
+                }
+            } catch (SocketException e) {
+                logger.info("Ignoring interface " + iface.getName(), e.fillInStackTrace());
+            }
+        }
+        return broadcastAddresses;
+    }
+
+    public boolean sendBroadcast(int port, byte[] data) {
+        boolean successful = false;
+        for (InetAddress broadcastAddress : getBroadcastAddresses()) {
+            try {
+                DatagramSocket socket = new DatagramSocket();
+                socket.setBroadcast(true);
+                DatagramPacket packet = new DatagramPacket(data, data.length, broadcastAddress, port);
+                socket.send(packet);
+                successful = true;
+            } catch (SocketException e) {
+                logger.warn("Failed to send broadcast to " + broadcastAddress +
+                        ". ", e.fillInStackTrace());
+            } catch (IOException e) {
+                logger.warn("Error when sending broadcast to " +
+                        broadcastAddress + ".", e.fillInStackTrace());
+            }
+        }
+        return successful;
+    }
+    
+    public static void main(String[] args) {
+        int port = Integer.parseInt(args[0]);
+        Broadcaster broadcaster = new Broadcaster();
+        String message = "Broadcast from Java broadcaster.";
+        broadcaster.sendBroadcast(port, message.getBytes());
+    }
+}