try {
mHandler.post(new myRunnable(“开始UDP连接”));
InetAddress serverAddress = InetAddress.getByName(“255.255.255.255”);//广泛广播地址
byte[] bytesToSend = “test_client”.getBytes();
int servPort = 6000;//与服务端一致的port
try {
DatagramSocket socket = new DatagramSocket();
socket.setSoTimeout(TIMEOUT);
DatagramPacket sendPacket = new DatagramPacket(bytesToSend,bytesToSend.length,serverAddress,servPort);
byte[] buf = new byte[1024];
DatagramPacket receivePacket = new DatagramPacket(buf, buf.length);
int tries = 0;
boolean receivedResponse = false;
do{
socket.send(sendPacket);
try{
socket.receive(receivePacket);
if(!receivePacket.getAddress().equals(serverAddress)){
System.out.println(“接收到了一个个未知来源的数据包”);
}
receivedResponse = true;
}catch(InterruptedIOException e){
tries +=1;
System.out.println(“Time out,”+(MAXTRIES – tries)+ ” more tries….”);
}
}
3.结果
if(receivedResponse){
String rcvd = “Received from ” + receivePacket.getAddress() + “, Data=”
+ new String(receivePacket.getData(), 0, receivePacket.getLength());
mHandler.post(new myRunnable(rcvd));
//System.out.println(“Received:”+new String(receivePacket.getData()));
//mHandler.post(new myRunnable(“Received:”+new String(receivePacket.getData())));
}else{
System.out.println(“NO response — giving up.”);
mHandler.post(new myRunnable(“NO response — giving up.”));
}
socket.close();
