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我正在开发一个使用 TCP 进行设备连接的 Android 应用程序。问题是我是套接字编程的新手。我已经成功制作了服务器和客户端代码。每个客户端都可以连接到服务器，服务器可以回复客户端。但我似乎无法让服务器同时向所有连接的客户端发送消息。使服务器向客户端广播消息的步骤是什么？这是服务器代码：

ServerSocket server = null;
try {
    server = new ServerSocket(9092); // start listening on the port
} catch (IOException e) {
    Log.d("btnCreate onClick", "Could not listen on port: 9092");
}
Socket client = null;
while(true) {
    try {
        client = server.accept();
    } catch (IOException e) {
        Log.d("btnCreate onClick", "Accept Failed");
    }
    //start a new thread to handle this client
    Thread t = new Thread(new ClientConn(client));
    t.start();
}

和服务器线程：

class ClientConn implements Runnable {
    private Socket client;

    ClientConn(Socket client) {
        this.client = client;
    }

    public void run() {
        BufferedReader in = null;
        PrintWriter out = null;
        try {
            /* obtain an input stream to this client ... */
            in = new BufferedReader(new InputStreamReader(
                        client.getInputStream()));
            /* ... and an output stream to the same client */
            out = new PrintWriter(client.getOutputStream(), true);
        } catch (IOException e) {
            e.printStackTrace();
            return;
        }

        String msg;
        try {
            while ((msg = in.readLine()) != null) {
                Log.d("ClientConn", "Client says: " + msg);
                out.println(msg);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
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1 回答 1

4

TCP 是一种点对点连接协议。这意味着当您在套接字上发送消息时，它只会发送给一个接收者。其他 IP 协议（​​例如 UDP）确实具有“广播”模式，其中一个数据包可以发送到多个接收者，但 TCP 没有这种情况。

To have your server send the same message to all clients, the server would have to send one message on each socket for each client.

于 2012-10-14T04:26:42.547 回答