我有一个局域网,我想从我的 android (htcdesire) 发送一条 udp 消息到我的电脑。它们之间有一个 WLAN 路由器。问题是,UPD 消息永远不会到达 PC。
Android上的代码:
package org.example.androidapp;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class UDPClientAnd {
public void sendUDPMessage(int port) throws java.io.IOException {
DatagramSocket socket = new DatagramSocket();
InetAddress serverIP = InetAddress.getByName("192.168.1.110");
byte[] outData = ("Ping").getBytes();
DatagramPacket out = new DatagramPacket(outData,outData.length, serverIP,50005);
socket.send(out);
socket.close();
}
}
我选择两边高的端口。
Android 上的权限是:
uses-permission android:name="android.permission.INTERNET"
uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"
服务器端是PC,只是一个简单的接收程序:
package org.example.androidapp;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
public class UPDServerAnd implements Runnable{
public void run(){
byte[] inData = new byte[48];
byte[] outData = new byte[48];
String message;
DatagramSocket socket;
try {
socket = new DatagramSocket(50005);
while (true) {
DatagramPacket in = new DatagramPacket(inData,inData.length);
socket.receive(in);
InetAddress senderIP = in.getAddress();
int senderPort = in.getPort();
message=new String(in.getData(),0,in.getLength());
System.out.println("Got "+message+" from "+senderIP+","+senderPort);
outData = "Pong".getBytes();
DatagramPacket out = new DatagramPacket(outData,outData.length, senderIP,senderPort);
socket.send(out);
}
} catch (SocketException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
那么为什么没有可见来自 android 的 UDP 包呢?即使 Wireshark 也只显示一些 ARP 包。
请帮忙:)