1 files changed, 82 insertions, 0 deletions
diff --git a/same-android/src/main/java/com/orbekk/discovery/Broadcast.java b/same-android/src/main/java/com/orbekk/discovery/Broadcast.java
new file mode 100644
index 0000000..5f592db
--- /dev/null
+++ b/same-android/src/main/java/com/orbekk/discovery/Broadcast.java
@@ -0,0 +1,82 @@
+package com.orbekk.discovery;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import android.content.Context;
+import android.net.DhcpInfo;
+import android.net.wifi.WifiManager;
+
+public class Broadcast {
+    private Context context;
+    private Logger logger = LoggerFactory.getLogger(getClass());
+    private DatagramSocket socket = null;
+    
+    public Broadcast(Context context) {
+        this.context = context;
+    }
+    
+    public synchronized InetAddress getBroadcastAddress() {
+        WifiManager wifi = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
+        DhcpInfo dhcp = wifi.getDhcpInfo();
+
+        int broadcast = (dhcp.ipAddress & dhcp.netmask) | ~dhcp.netmask;
+        byte[] quads = new byte[4];
+        for (int k = 0; k < 4; k++)
+          quads[k] = (byte) ((broadcast >> k * 8) & 0xFF);
+        try {
+            return InetAddress.getByAddress(quads);
+        } catch (UnknownHostException e) {
+            logger.warn("Failed to find broadcast address.");
+            return null;
+        }
+    }
+    
+    public synchronized boolean sendBroadcast(byte[] data, int port) {
+        try {
+            socket = new DatagramSocket(port);
+            socket.setBroadcast(true);
+            DatagramPacket packet = new DatagramPacket(data, data.length, getBroadcastAddress(), port);
+            socket.send(packet);
+            return true;
+        } catch (SocketException e) {
+            logger.warn("Failed to send broadcast.", e.fillInStackTrace());
+            return false;
+        } catch (IOException e) {
+            logger.warn("Error when sending broadcast.", e.fillInStackTrace());
+            return false;
+        } finally {
+            socket.close();
+            socket = null;
+        }
+    }
+    
+    public synchronized DatagramPacket receiveBroadcast(int port) {
+        try {
+            socket = new DatagramSocket(port);
+            byte[] data = new byte[1024];
+            DatagramPacket packet = new DatagramPacket(data, data.length);
+            socket.receive(packet);
+            return packet;
+        } catch (IOException e) {
+            logger.warn("Failed to receive broadcast.", e);
+            return null;
+        } finally {
+            socket.close();
+            socket = null;
+        }
+    }
+    
+    public void interrupt() {
+        if (socket != null) {
+            socket.close();
+        }
+    }
+}
+\ No newline at end of file