如何让 Java TCP 服务器和客户端应用程序循环，直到发出一定数量的请求

Question

我已经在 eclipse 中编写了一个 TCP 服务器和一个 TCP 客户端应用程序。客户端以字符串的形式获取用户输入，然后将其发送到服务器，服务器将其大写并发回。他们需要继续循环，直到服务器收到一定数量的请求，在这种情况下，它会关闭套接字之间的连接并停止。不幸的是，它似乎只循环一次。我将在代码之后提供我正在谈论的内容的示例输出。

import java.io.*;
import java.net.*;

public class TCPServer {
public static void main(String argv[]) throws Exception {
String clientSentence;
String capitalizedSentence;
ServerSocket welcomeSocket = new ServerSocket(6789);
int requests = 0;
while (true) {
Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient = new BufferedReader (new InputStreamReader( connectionSocket.getInputStream()));
DataOutputStream outToClient = new DataOutputStream (connectionSocket.getOutputStream());
do {
clientSentence = inFromClient.readLine();
capitalizedSentence = clientSentence.toUpperCase() + 'n';
outToClient.writeBytes(capitalizedSentence);
outToClient.flush();
requests++;
}
while(requests < 10);
outToClient.writeBytes("REQUEST LIMIT REACHED");
}
}
}

和客户

import java.io.*;
import java.net.*;
public class TCPClient {
public static void main(String argv[]) throws Exception {
String sentence;
String modifiedSentence;
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
//Creates socket, replace the hostnmae/ip address with the ipaddress of the computer running the server application.
Socket clientSocket = new Socket("10.69.88.130", 6789);
DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
BufferedReader inFromServer = new BufferedReader(new InputStreamReader (clientSocket.getInputStream()));
do {
System.out.print("TO SERVER: ");
sentence = inFromUser.readLine();
outToServer.writeBytes(sentence + 'n');
outToServer.flush();
modifiedSentence = inFromServer.readLine();
System.out.println("FROM SERVER: " + modifiedSentence);
}
while (!modifiedSentence.equals("REQUEST LIMIT REACHED"));
System.out.println(modifiedSentence);
clientSocket.close();
}
}

最后是我得到的输出

TO SERVER: testa
FROM SERVER: TESTA
TO SERVER: testb
(nothing else is displayed after this line)

Answer 1

好吧，你的代码正在工作(有点(。您成功运行，然后重新启动客户端而不重新启动服务器。您的request-value 不会重置为 0，重新启动客户端后，客户端对服务器执行的第一个请求是第 10 个。 那么，为什么会有这个请求通过呢？因为您先刷新字符串，然后再检查计数器。

我已经稍微修改了您的服务器。也许这就是你要找的？

import java.io.*;
import java.net.*;

public class TCPServer {
public static void main(String argv[]) throws Exception {
String clientSentence;
String capitalizedSentence;
ServerSocket welcomeSocket = new ServerSocket(6789);
int requests = 0;
while (true) {
Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient = new BufferedReader (new InputStreamReader( connectionSocket.getInputStream()));
DataOutputStream outToClient = new DataOutputStream (connectionSocket.getOutputStream());
while (requests < 10) {
clientSentence = inFromClient.readLine();
capitalizedSentence = clientSentence.toUpperCase();
outToClient.writeBytes(capitalizedSentence + " Request: " + requests +  'n');
outToClient.flush();
requests++;
}
outToClient.writeBytes("REQUEST LIMIT REACHED");
requests = 0;
}
}
}