Question

How to return action to while loop in a switch statement ? The client is unable to return to while statement. I meant to say, whenever response comes from server, the client must start from while loop again, so that client can select his choices. Is it a problem of System.out ? (Note: It’s a copied code from others) Here are the client and server :

Client:

    .............
while (true) {
       String userchoice = console.readLine("Enter your choice :"); 
       int choice= Integer.parseInt(userchoice);
      switch (choice){  
    ..........
    case 2: // for viewing files in the client's directory
      try{
      Socket mysoc = new Socket("localhost", 9001);
      String user_name = username;
      DataOutputStream ToServer = new DataOutputStream(mysoc.getOutputStream());
      ToServer.writeBytes(user_name + '\n');
      BufferedReader FromServer = new BufferedReader(new InputStreamReader(mysoc.getInputStream()));
      String line = null;
      while ((line = FromServer.readLine()) != null) {
       System.out.println(line);
      } 
     }
    catch(Exception e)
            {
                e.printStackTrace();
                System.exit(0);
            }
      break;
      ............
}

Server:

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

class DirList
{
   public static void main(String argv[]) throws Exception
      {
         String clientString;
         //String replyString;
         ServerSocket welcomeSoc = new ServerSocket(9001);

         while(true)
         {
            Socket connectionSocket = welcomeSoc.accept();
            BufferedReader FromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
            PrintWriter ToClient = new PrintWriter(connectionSocket.getOutputStream(),true);
            clientString = FromClient.readLine();
            System.out.println("Received view songs request from : " + clientString);
            String path = "/home/sri/Songs/";
            String text="";
            File f = new File(path);
                File[] listOfFiles = f.listFiles();
                for (int j = 0; j < listOfFiles.length; j++) {
                        if (listOfFiles[j].isFile()) {
                                text = listOfFiles[j].getName();
                                ToClient.println(text);
                   }
                }


         }
      }
}

Answer 1

try to close your PrintWriter and Socket in the Server code after they finished their task.

@Sri, about the question you’ve asked in the comment:

by Socket I meant connectionSocket. ServerSocket will remain there during your server life time. But you will have a new connectionSocket for each user. so each connectionSocket will serve only a single client.