我有一个服务器应用程序和客户端应用程序在不同的 android 设备上分别运行，并且正在从客户端应用程序和服务器在 LAN 中广播消息，但问题是消息只在服务器上接收一次，我的客户端代码是：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bt=(Button)findViewById(R.id.myButton);
bt.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
et = (EditText) findViewById(R.id.EditText01);
str = et.getText().toString();
new Thread(new ClientThread()).start();
}
});
}
/*
private InetAddress getBroadcastAddress() throws IOException {
DhcpInfo dhcp = mWifi.getDhcpInfo();
if (dhcp == null) {
//Log.d(TAG, "Could not get dhcp info");
return null;
}
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);
return InetAddress.getByAddress(quads);
}
*/
class ClientThread implements Runnable {
@Override
public void run() {
try {
socket = new DatagramSocket(SERVERPORT);
socket.setBroadcast(true);
// socket.setSoTimeout(TIMEOUT_MS);
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
InetAddress serverAddr = null;
try {
serverAddr = InetAddress.getByName(SERVER_IP);
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
packet = new DatagramPacket(str.getBytes(), str.length(),serverAddr,SERVERPORT);
try {
socket.send(packet);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
我的服务器类是：
public class MainActivity extends Activity {
private Boolean shouldRestartSocketListen=true;
TextView tv1;
//MulticastLock lock;
static String UDP_BROADCAST = "UDPBroadcast";
DatagramSocket socket=null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv1=(TextView)findViewById(R.id.textView1);
startListenForUDPBroadcast();
}
private void listenAndWaitAndThrowIntent(InetAddress broadcastIP, Integer port) throws Exception {
byte[] recvBuf = new byte[15000];
// if (socket == null || socket.isClosed()) {
//socket.setBroadcast(true);
// }
//socket.setSoTimeout(1000);
DatagramPacket packet = new DatagramPacket(recvBuf, recvBuf.length);
while(true)
{
socket = new DatagramSocket(port, broadcastIP);
Log.e("UDP", "Waiting for UDP broadcast");
socket.receive(packet);
// String senderIP = packet.getAddress().getHostAddress();
String message = new String(packet.getData()).trim();
// Log.e("UDP", "Got UDB broadcast from " + senderIP + ", message: " + message);
tv1.setText(message);
}
// broadcastIntent(senderIP, message);
// socket.close();
}
private void broadcastIntent(String senderIP, String message) {
Intent intent = new Intent(MainActivity.UDP_BROADCAST);
intent.putExtra("sender", senderIP);
intent.putExtra("message", message);
sendBroadcast(intent);
}
Thread UDPBroadcastThread;
void startListenForUDPBroadcast() {
UDPBroadcastThread = new Thread(new Runnable() {
public void run() {
try {
InetAddress broadcastIP = InetAddress.getByName("192.168.1.255"); //172.16.238.42 //192.168.1.255
Integer port = 11111;
while (shouldRestartSocketListen) {
listenAndWaitAndThrowIntent(broadcastIP, port);
}
//if (!shouldListenForUDPBroadcast) throw new ThreadDeath();
} catch (Exception e) {
Log.i("UDP", "no longer listening for UDP broadcasts cause of error " + e.getMessage());
}
}
});
UDPBroadcastThread.start();
}
void stopListen() {
shouldRestartSocketListen = false;
socket.close();
}
public void onCreate() {
};
@Override
public void onDestroy() {
stopListen();
}
public IBinder onBind(Intent intent) {
return null;
}
}