如何在Android中使用UDP接收数据？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/3102048/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
提示：将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间：2020-08-20 08:41:40 来源:igfitidea点击:
How to receive data using UDP in Android?
提问by Android
I use the following code to receive the data from a particular port. It's not working in Android. But sending data to particular port is working fine.
我使用以下代码从特定端口接收数据。它在 Android 中不起作用。但是将数据发送到特定端口工作正常。
public class UDPDemo extends Activity {
private TextView tv;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv = (TextView)findViewById(R.id.recv_message);
try {
DatagramSocket clientsocket=new DatagramSocket(9876);
byte[] receivedata = new byte[1024];
while(true)
{
DatagramPacket recv_packet = new DatagramPacket(receivedata, receivedata.length);
Log.d("UDP", "S: Receiving...");
clientsocket.receive(recv_packet);
String rec_str = new String(recv_packet.getData());
tv.setText(rec_str);
Log.d(" Received String ",rec_str);
InetAddress ipaddress = recv_packet.getAddress();
int port = recv_packet.getPort();
Log.d("IPAddress : ",ipaddress.toString());
Log.d(" Port : ",Integer.toString(port));
}
} catch (Exception e) {
Log.e("UDP", "S: Error", e);
}
}
}
回答by ktingle
回答by Jayakrishnan PM
Create Datagram packet
创建数据报包
try {
mDataGramSocket = new DatagramSocket(Config.PORT_NUMBER);
mDataGramSocket.setReuseAddress(true);
mDataGramSocket.setSoTimeout(1000);
} catch (SocketException e) {
e.printStackTrace();
}
Call below function through AsyncTask
通过 AsyncTask 调用下面的函数
Create Function to receive infinitely
创建函数以无限接收
public void receive() {
String text;
byte[] message = new byte[1500];
DatagramPacket p = new DatagramPacket(message, message.length);
try {
while (true) { // && counter < 100 TODO
// send to server omitted
try {
mDataGramSocket.receive(p);
text = new String(message, 0, p.getLength());
// If you're not using an infinite loop:
//mDataGramSocket.close();
} catch (SocketTimeoutException | NullPointerException e) {
// no response received after 1 second. continue sending
e.printStackTrace();
}
}
} catch (Exception e) {
e.printStackTrace();
// return "error:" + e.getMessage();
mReceiveTask.publish("error:" + e.getMessage());
}
// return "out";
}
