我正在尝试制作一个能够向计算机发送消息并从中接收消息的 Android 应用程序。这是非常基本的。问题是,我已经通过多播实现了这一点,尽管并不完全如此。我的应用程序能够从计算机接收消息(它使用我制作的 java 应用程序来接收和发送消息)。但是,当我尝试从设备向计算机发送消息时,消息不会到达计算机。我的意思是,应用程序。
桌面应用程序和 Android 应用程序都使用相同的客户端 - 服务器类。这就是让我如此困惑的原因。因为,当我使用相同的类时,为什么它以一种方式工作而不是另一种?我只是不不。
桌面应用程序在 Windows 上运行。
此外,当 Android 应用程序收到一条消息时,它会通过以下方式接收它:“Message 1����������������������������... " 何时应收到消息:"消息 1"。我不知道这是否相关。
代码如下:
服务器类:
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.UnknownHostException;
public class MulticastSocketServer implements Runnable{
final static String INET_ADDR = "224.0.0.3";
final static int PORT = 8888;
static String msg;
public MulticastSocketServer(String message) throws UnknownHostException, InterruptedException {
msg = message;
Thread thread = new Thread(this);
thread.start();
}
@Override
public void run() {
// TODO Auto-generated method stub
// Get the address that we are going to connect to.
InetAddress addr = null;
try {
addr = InetAddress.getByName(INET_ADDR);
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// Open a new DatagramSocket, which will be used to send the data.
try (DatagramSocket serverSocket = new DatagramSocket()) {
msg += "\\0";
for (int i = 0; i < 10; i++) {
// Create a packet that will contain the data
// (in the form of bytes) and send it.
DatagramPacket msgPacket = new DatagramPacket(msg.getBytes(),
msg.getBytes().length, addr, PORT);
serverSocket.send(msgPacket);
System.out.println("Server sent packet with msg: " + msg);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
serverSocket.disconnect();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
客户端类:
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.UnknownHostException;
import java.util.Timer;
import java.util.TimerTask;
public class MulticastSocketClient implements Runnable {
final static String INET_ADDR = "224.0.0.3";
final static int PORT = 8888;
Connection360 conn;
public MulticastSocketClient (Connection360 connection) throws UnknownHostException {
conn = connection;
Thread thread = new Thread(this);
thread.start();
}
@Override
public void run() {
try{
// Get the address that we are going to connect to.
InetAddress address = InetAddress.getByName(INET_ADDR);
// Create a buffer of bytes, which will be used to store
// the incoming bytes containing the information from the server.
// Since the message is small here, 256 bytes should be enough.
byte[] buf = new byte[256];
// Create a new Multicast socket (that will allow other sockets/programs
// to join it as well.
try (final MulticastSocket clientSocket = new MulticastSocket(PORT)){
//Joint the Multicast group.
clientSocket.joinGroup(address);
System.out.println("Connected");
//while (true) {
// Receive the information and print it.
DatagramPacket msgPacket = new DatagramPacket(buf, buf.length);
Timer timer = new Timer("tmr");
timer.schedule(new TimerTask() {
@Override
public void run() {
clientSocket.disconnect();
}
},10000);
clientSocket.receive(msgPacket);
String msg = new String(buf, 0, buf.length);
System.out.println("Socket 1 received msg: " + msg.substring(0, msg.indexOf("\\0")));
conn.MessageReceived(msg.substring(0, msg.indexOf("\\0")));
clientSocket.disconnect();
//}
} catch (IOException ex) {
ex.printStackTrace();
}
}catch (UnknownHostException ex){
}
}
}
这个类是我为桌面应用程序制作的。我为 Android 应用程序制作的类是相同的,但我必须将其更改System.out.println()
为Log.v()
. 至于其他的,一模一样。
因此,如果您碰巧知道会发生什么,我将非常感谢您在该主题方面的帮助。
谢谢!