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Question

我想知道是否有两个程序，一个名为server，另一个名为client，这两个程序分别说明服务器和客户端，是否可以在一台机器上测试它们？考虑到我定义了客户端套接字如下：

socket = new Socket("127.0.0.1",3000);

编辑：服务器部分：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

class TCPServer
{
       private static ServerSocket serverSocket;
        private static Socket socket;
        private static PrintWriter toClient;
        private static BufferedReader fromClient;
        public static void run() throws IOException
            {
            System.out.println("Server is waiting for connections...");
            while (true)
            {
                openStreams();
                processClient();
                closeStreams();
            }

        }

        public static void openStreams() throws IOException
            {
            serverSocket = new ServerSocket(3000);
            socket = serverSocket.accept();
            toClient = new PrintWriter(socket.getOutputStream(),true);
            fromClient = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        }
        public static void closeStreams() throws IOException
            {
            fromClient.close();
            toClient.close();
            socket.close();
            serverSocket.close();
        }
      public static void processClient()throws IOException
{
    String msg = null;
    do {
        msg = fromClient.readLine();
        toClient.println("Client said " + msg);
    } while (!"exit".equals(msg));
}

        }

客户端部分：

package clientserver.pkg1;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

class TCPClient
{
      private PrintWriter toServer;
            private BufferedReader fromServer;
            private Socket socket;
            public void Client( )throws IOException
                {
                socket = new Socket("127.0.0.1",3000);
            }
            public void openStreams() throws IOException
         {

                toServer = new PrintWriter(socket.getOutputStream(),true);
                fromServer = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            }
            public void closeStreams() throws IOException
                {
                fromServer.close();
                toServer.close();
                socket.close();
            }
          public void run()throws IOException
{
    openStreams();
    String msg = "";
    Scanner scanner = new Scanner(System.in);
    while (!"exit".equals(msg))
    {
        System.out.print(">");
        msg = scanner.nextLine();
        toServer.println(msg);
        String tmp = fromServer.readLine();
        System.out.println("Server said: " + tmp);
    }
    closeStreams();
}

            }

主要班级

public static void main(String[] args) {

       try
            {
                 TCPServer server = new TCPServer() {};
                 TCPClient client = new TCPClient();
                 client.run();
                 server.run();




            }
            catch(IOException e)
            {
                 System.err.println("Error in Client " + e.getMessage());
            }




java.lang.NullPointerException

1

toServer = new PrintWriter(socket.getOutputStream(),true);

2

      public void run()throws IOException
{
    openStreams();
.....
}

3

 public static void main(String[] args) {

       try
            {
                 TCPClient client = new TCPClient();
                 client.run();
            }

在client.run();

Answer 1

是的，你可以写这样的程序。有一个useful tutorial for this。简而言之，这一切都归结为准备一个ServerSocket：

ServerSocket createSocket() {
    ServerSocket serverSocket;
    try {
        serverSocket = new ServerSocket(3000);
    } catch (IOException ex) {
        ex.printStackTrace(System.err);
        throw ex;
    }
    return serverSocket;
}

从程序员的角度来看，驻留在远程计算机上的服务器或本地服务器之间没有区别。

您可以尝试编写两个不同的程序，一个用于服务器，另一个用于客户端。这是客户的主要内容：

public static void main(String[] args) {
  try {
      TCPClient client = new TCPClient() {};
      client.run();
  } catch(IOException e) {
    System.err.println("Error in Client " + e.getMessage());
  }

这对于服务器来说：

public static void main(String[] args) {
  try {
      TCPServer server = new TCPServer() {};
      server.run();
  } catch(IOException e) {
    System.err.println("Error in Server " + e.getMessage());
  }

然后首先运行服务器，然后在另一个控制台中运行客户端。

Answer 2

当然，您可以在同一台机器上测试它们。几年前，我使用套接字制作了类似聊天的应用程序，并且在我使用不同的机器进行测试之前，我将它测试到了同一台机器，这很好，。

Answer 3

您当然可以，只需将客户端和服务器连接到相同的端口号即可。

Answer 4

您可以在PC的端口上读/写，与您在网络中的位置无关

在单个系统上运行客户端/服务器prog

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4 个答案: