我使用了一个线程用于UDP接收数据包。当我向特定IP发送数据包时,UDP接收程序运行。不幸的是,该应用程序将被停止。然后,如果我删除名为new Thread(new Runnable())
和public void run
的线程,应用程序将运行良好,但只收到一个数据。我的目的是在数据到来时不断地在接收端接收数据。请认出我。
udpserver.java:
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class UdpServer extends Activity {
/** Called when the activity is first created. */
private TextView data;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
data = (TextView) findViewById(R.id.textView);
runUdpServer();
}
private static final int UDP_SERVER_PORT = 11111;
private static final int MAX_UDP_DATAGRAM_LEN = 1500;
private void runUdpServer() {
new Thread(new Runnable() {
public void run() {
String lText;
byte[] lMsg = new byte[MAX_UDP_DATAGRAM_LEN];
DatagramPacket dp = new DatagramPacket(lMsg, lMsg.length);
DatagramSocket ds=null;
try {
ds = new DatagramSocket(UDP_SERVER_PORT);
//disable timeout for testing
//ds.setSoTimeout(100000);
ds.receive(dp);
lText = new String(dp.getData());
Log.i("UDP packet received", lText);
data.setText(lText);
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
finally {
if (ds != null) {
ds.close();
}
}
}
}).start();
}
答案 0 :(得分:1)
这是我用来接收和解析UDP数据包的工作片段。
try {
int port = 11000;
DatagramSocket dsocket = new DatagramSocket(port);
byte[] buffer = new byte[2048];
DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
while (true) {
dsocket.receive(packet);
lText = new String(buffer, 0, packet.getLength());
Log.i("UDP packet received", lText);
data.setText(lText);
packet.setLength(buffer.length);
}
} catch (Exception e) {
System.err.println(e);
e.printStackTrace();
}
答案 1 :(得分:0)
您可以设置循环以从udp套接字读取数据。
try {
ds = new DatagramSocket(UDP_SERVER_PORT);
//disable timeout for testing
//ds.setSoTimeout(100000);
while (!ds.isClosed()) {
ds.receive(dp);
lText += new String(dp.getData());
Log.i("UDP packet received", new String(dp.getData());
runOnUiThread(new Runnable() {
public void run() {
data.setText(lText);
}
});
}
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (ds != null) {
ds.close();
}
}
UPDATE :由于在非UI线程中接收到数据包数据。直接访问工作线程中的data.setText(lText)无效。
答案 2 :(得分:-1)
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);
}