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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(0);
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();
}
}
}
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