java - 编写简单的控制台聊天程序

Question

所以。我正在编写这个简单的聊天程序，基本上它是如何工作的，客户端和服务器轮流编写消息。现在我希望客户端和服务器能够连续发送多条消息，而不是等待对方。

有关如何发送多条消息以及接收多条消息的任何建议。

我是网络应用程序的新手。

Client的运行方法:

public void run(){
    while (true){
        System.out.println("Write message to server:");
        String besked = scanner.nextLine();
        oos.writeObject(besked);
        System.out.println("MEssage from server: " + (String)ois.readObject());
        oos.flush();
    }   
}        

以及Server的运行方法:

  public void run() {
      while(true){
              String s = (String)ois.readObject();
              System.out.println("Message from client: " +s);

              System.out.println("Write back:");
              String returbesked = scanner.nextLine();
              oos.writeObject(returbesked);
              oos.flush();
       }
  }

Answer 1

您可以使用两个线程，(对于连接的每一侧)一个从套接字读取数据，另一个将数据写入套接字。当服务器接受客户端连接时，它会创建两个线程(在代码示例中，它们称为 Reader 和 Writer 线程)。当写入线程不断从源获取一些数据并将数据输出到套接字时，同时读取线程不断从套接字读取数据。套接字连接的输入和输出流彼此独立，因此可以同时使用。

在下面的代码中，我尝试实现服务器端，但对于客户端来说也几乎相同:

public class Test {

    public static void main(String[] args) {
        Server server = new Server();
        server.start(100);  // server port no 100
    }

}

class Server {

    /**
     * Thread that continuously reads data from socket.
     */
    private Thread reader;

    /**
     * Thread that continuously writes data to socket.
     */
    private Thread writer;

    /**
     * Start server
     * @param port
     * @throws IOException
     */
    void start(int port) throws IOException {
        ServerSocket srv = new ServerSocket(port);

        // Wait for client connection
        Socket clientSocket = srv.accept();

        // Client connected
        startReadingAndWritingData(clientSocket);
    }

    /**
     * Starts reader and writer threads.
     * 
     * @param socket
     *            client socket
     * @throws IOException
     */
    private void startReadingAndWritingData(Socket socket) throws IOException {
        ObjectInputStream ois = new ObjectInputStream(new BufferedInputStream(
                socket.getInputStream()));

        ObjectOutputStream oos = new ObjectOutputStream(
                new BufferedOutputStream(socket.getOutputStream()));

        ReaderThread reader = new ReaderThread(ois);
        WriterThread writer = new WriterThread(oos);
            reader.start();
            writer.start();

    }
}

class WriterThread extends Thread {

    private ObjectOutputStream oos;

    /**
     * Constructor.
     * 
     * @param oos
     */
    WriterThread(ObjectOutputStream oos) {
        super();
        this.oos = oos;
    }

    public void run() {
        while (true) {
            try {
                String output = getNextOutput();
                oos.writeObject(output);

                Thread.sleep(1000); // Wait before sending next String
            } catch (Exception e) {
                /*
                 * Socket IO or serialization error
                 */
                e.printStackTrace();
                break;
            }
        }
    }

    /**
     * Get output String from somewhere eg. file.
     * 
     * @return output
     */
    private String getNextOutput() {
        // TODO get output String from somewhere
    }

}

/**
 * Reader thread.
 * 
 */
class ReaderThread extends Thread {

    private ObjectInputStream ois;

    /**
     * Constructor.
     * 
     * @param ois
     */
    ReaderThread(ObjectInputStream ois) {
        super();
        this.ois = ois;
    }

    public void run() {
        while (true) {
            try {
                String input = (String) ois.readObject();
                handleInput(input);
            } catch (Exception e) {
                /*
                 * Socket IO or deserialization error
                 */
                e.printStackTrace();
                break;
            }
        }
    }

    /**
     * Handle received input String.
     * 
     * @param input
     */
    private void handleInput(String input) {
        // TODO handle input

    }

}