java - 多线程似乎不起作用

Question

我有 2 个类，一个服务器和一个客户端。服务器使用多个线程来接受许多客户端。所以 x 个客户端可以加入同一台服务器。然而，在尝试从客户端方法识别线程时，我似乎发现它没有创建多个线程，因为所有客户端的 ID 都相同。我的代码如下:

服务器:

public class Server
{
    ServerSocket serverSocket;
    int portNumber;
    public static volatile String userInput;
    public volatile int noOfClients = 0;

public static void main(String[] args)
{
    Server s = new Server();
    s.startup();
}


/**
 * Start the server on the user picked port
 */
public void startup()
{   
    try 
    {
        System.out.println("Enter a port");
        Scanner dif = new Scanner(System.in);
        portNumber = Integer.parseInt(dif.nextLine());
        dif.close();

        serverSocket = new ServerSocket(portNumber);
        newThread();
    }
    catch (IOException e) {
        System.out.println("Error");
        System.exit(0);
    }
}


public void newThread()
{
    Thread thread =new Thread()
    {

        public void run()
        {   
            while(true) {
                try {

                    accept();
                } catch (Exception e) {
                    System.out.println("Error");
                }
            }
        }
    };
    thread.start();
}

public void accept()
{
    try
    {
        Socket clientSocket = serverSocket.accept();
        new Thread(new ClientSocket(clientSocket)).start();
        System.out.println("A new client has just connected.");
        noOfClients++;

    } catch(IOException e)
    {
        System.out.println("Error");
        System.exit(0);
    }
}


class ClientSocket implements Runnable {
    Socket clientSocket;

    public ClientSocket(Socket clientSocket) {
        this.clientSocket = clientSocket;
    }

    public void run() {
        {
            try
            {
                PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);                   
                BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

                while (true)
                {
                    userInput = in.readLine();
                }

            } catch (IOException e)
            {
                System.out.println("Error");
            }
        }
    }
}
}

客户:

public class Client
{
    Socket clientSocket;
    public static int threadName;


public static void main(String[] args) throws IOException {
    String hostName = args[0];
    int portNumber = Integer.parseInt(args[1]);


    try {
        Socket serverSocket = new Socket(hostName, portNumber);
        PrintWriter out = new PrintWriter(serverSocket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(new InputStreamReader(serverSocket.getInputStream()));
        BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));

        Thread thread = Thread.currentThread();
        System.out.println("RunnableJob is being run by " + thread.getName() + " (" + thread.getId() + ")");
        String userInput;

        while ((userInput = stdIn.readLine()) != null)
        {

            out.println(userInput);
            System.out.println("Server: " + userInput);
        }

    } catch(UnknownHostException e) {
        System.out.println("error in host");
    } catch(IOException e) {
        System.out.println("error in IO");
    }


}
}

当运行两个单独的客户端时，

System.out.println("RunnableJob is being run by " + thread.getName() + " (" + thread.getId() + ")");

一行代码打印出相同的结果。我该如何修复它，以便每个新的客户端连接都在自己的唯一线程内启动。那么 2 个客户端总共有 2 个线程？谢谢:)

Answer 1

首先，您要检查客户端的线程 ID，它们彼此独立，因此这是行不通的。

但是，使用线程 ID 并不是识别客户端的好方法。相反，为什么不记录客户端数量，然后当新客户端加入时，增加该数字并将该数字作为 id 提供给客户端对象。