如何在Java客戶端服務器程序中從控制檯獲取輸入

我寫了一個簡單的客戶端服務器程序。我能夠從客戶端發送文本到服務器，反之亦然。但是，在客戶端上打印服務器數據後，我無法在客戶端的CLI上打印任何內容。如何在Java客戶端服務器程序中從控制檯獲取輸入

我不知道我在做什麼錯。我懷疑行中的錯誤評論爲「Bug Here」。我無法找到那些線路上有什麼問題。

請在下面找到我的代碼。

ATMClient.java

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

public class ATMClient 
{ 
    public static void main(String args[]) 
    { 
     try 
     { 
      Socket sock = new Socket("localhost", 9010); 
      sock.setSoTimeout(10000); 
      System.out.println("Connection established"); 
      String data = null; 

      InputStreamReader input = new InputStreamReader(sock.getInputStream()); 
      BufferedReader bread = new BufferedReader(input); 

      BufferedReader brCli = new BufferedReader(new InputStreamReader(System.in)); 
      System.out.print("Enter text to be sent to Server: "); 
      String strCli = brCli.readLine(); 

      PrintWriter pwrite = new PrintWriter(sock.getOutputStream(), true); 
      pwrite.println(strCli); 

     // Bug Here: The control in not coming out of the while loop 
      while((data = bread.readLine()) != null) 
      { 
       System.out.println(data); 
      } 

     // Bug Here: The following line does not get printed. 
      System.out.print("Enter an Option: "); 

      pwrite.close(); 
      bread.close(); 
      input.close(); 
     } 
     catch(IOException ex) 
     { 
      System.err.println(ex); 
     } 
    } 
}

ATMServer.java

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

public class ATMServer 
{ 
    public static void main(String args[]) 
    { 
     try 
     { 
      ServerSocket server = new ServerSocket(9010); 
      Socket client = server.accept(); 
      System.out.println("Connection Established"); 

      InputStream input = client.getInputStream(); 
      BufferedReader bufread = new BufferedReader(new InputStreamReader(input)); 

      PrintWriter pwrite = new PrintWriter(client.getOutputStream(), true); 

      pwrite.println("1. Deposit"); 
      pwrite.println("2. Withdrawal"); 
      pwrite.println("3. Balance"); 
      pwrite.println("4. Exit"); 

      String data = null; 
      while((data = bufread.readLine()) != null) 
      { 
       System.out.println(data); 
      } 

      pwrite.close(); 
      bufread.close(); 
      input.close(); 
      server.close(); 
      client.close(); 
     } 
     catch(Exception ex) 
     { 
      System.err.println(ex); 
     } 
    } 
}

輸出：

user1$ java ATMServer 
Connection Established 
hello 

user1$ java ATMClient 
Connection established 
Enter text to be sent to Server: hello 
1. Deposit 
2. Withdrawal 
3. Balance 
4. Exit 
Deposit 
^C user1$

你能幫我搞清楚如何獲得客戶端的控制檯上輸入？謝謝。

來源

2015-10-05 Anit

只要從遠程套接字輸入流是開放的， bread.readLine()不會返回null，因此這個循環將永遠不會結束：

while((data = bread.readLine()) != null) 
{ 
    System.out.println(data); 
}

您需要添加某種信號，對例如文本「ENDMSG」。服務器應該在與客戶端交談時發送該消息，並且客戶端應該如此識別並退出循環。例如：

while((data = bread.readLine()) != null) 
{ 
    if (data.equals("ENDMSG")) { 
     break; 
    } 
    System.out.println(data); 
}

來源

2015-10-05 15:27:13 janos

如何在Java客戶端服務器程序中從控制檯獲取輸入

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