Interview Questions

In Code Sample:A multi-threaded DateServe that listens on port 3000 and waits for requests from clients

An Introduction to Socket Programming

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In Code Sample:A multi-threaded DateServe that listens on port 3000 and waits for requests from clients

Here A multi-threaded DateServer that listens on port 3000 and waits for requests from clients. Whenever there is a request, the server replies by sending a Date object (over sockets) to the client as shown in Code Sample. 

Code Sample: DateServer.java
import java.io.*;
import java.net.*;
import java.util.*;

public class DateServer 
 extends Thread {

   private ServerSocket dateServer;
 

   public static void main
   (String argv[]) throws Exception {
     new DateServer();
   }

public DateServer() throws Exception {
     dateServer = new ServerSocket(3000);
     System.out.println
     ("Server listening on port 3000.");
     this.start();
   } 

   public void run() {
     while(true) {
       try {
System.out.println("Waiting for connections.");
Socket client = dateServer.accept();
System.out.println("Accepted a connection
 from: "+ client.getInetAddress());
        Connect c = new Connect(client);
       } catch(Exception e) {}
     }
   }
}

class Connect extends Thread {
   private Socket client = null;
   private ObjectInputStream ois = null;
   private ObjectOutputStream oos = null;
    
   public Connect() {}

   public Connect(Socket clientSocket) {
     client = clientSocket;
     try {
      ois = new ObjectInputStream
      (client.getInputStream());
      oos = new ObjectOutputStream
      (client.getOutputStream());
     } catch(Exception e1) {
         try {
            client.close();
         }catch(Exception e) {
 System.out.println(e.getMessage());
         }
         return;
     }
     this.start();
   }

  
   public void run() {
      try {
         oos.writeObject(new Date());
         oos.flush();
// close streams and connections
         ois.close();
         oos.close();
         client.close(); 
      } catch(Exception e) {}       
   }
}

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