Savitribai Phule Pune University T.Y.B.B.A.(C.A.) Advanced Java Practical Slip 18 Answers

 

A) Write a java program to calculate factorial of a number. (Use sleep () method).

Answer :

import java.io.*;

public class Slip18A {

    public static void main(String args[]) {

        alpha a1 = new alpha();

        a1.start();

    }

}

 

class alpha extends Thread {

    public void run() {

        try {

            DataInputStream br = new DataInputStream(System.in);

            System.out.print("Enter Number : ");

            int n = Integer.parseInt(br.readLine());

            int a = 0, b = 1;

            for (int i = 1; i <= n; ++i) {

                System.out.print(a + " | ");

                int c = a + b;

                a = b;

                b = c;

                sleep(1000);

            }

        } catch (Exception e) {

        }

    }

}

B) Write a java program for simple standalone chatting application.

Answer : 

Server Code:

import java.io.*;

import java.net.*;

public class ChatServer {

    public static void main(String[] args) throws Exception {

        ServerSocket serverSocket = new ServerSocket(5000); // Start server on port 5000

        System.out.println("Server started. Waiting for clients to connect...");

        Socket clientSocket = serverSocket.accept(); // Wait for client to connect

        System.out.println("Client connected.");

        BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

        PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);

        BufferedReader consoleIn = new BufferedReader(new InputStreamReader(System.in));

        String inputLine;

        while ((inputLine = in.readLine()) != null) {

            System.out.println("Client: " + inputLine); // Display client message

            String response = consoleIn.readLine(); // Read server response from console

            out.println(response); // Send server response to client

        }

        in.close();

        out.close();

        clientSocket.close();

        serverSocket.close();

    }

}

Client Code:

import java.io.*;

import java.net.*;

public class ChatClient {

    public static void main(String[] args) throws Exception {

        Socket socket = new Socket("localhost", 5000); // Connect to server on port 5000

        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

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

        BufferedReader consoleIn = new BufferedReader(new InputStreamReader(System.in));

        String inputLine;

        while ((inputLine = consoleIn.readLine()) != null) {

            out.println(inputLine); // Send client message to server

            String response = in.readLine(); // Read server response

            System.out.println("Server: " + response); // Display server response

        }

        in.close();

        out.close();

        socket.close();

    }

}