Slip No 3

Q.A Write a socket program in Java to check whether given number is prime or not. Display result on client terminal.

Server Program (PrimeServer.java)

import java.net.*;
import java.io.;
public class PrimeServer {
// Method to check prime number
static boolean isPrime(int num) {
    if (num <= 1)
        return false;
    for (int i = 2; i <= Math.sqrt(num); i++) {
        if (num % i == 0)
            return false;
    }
    return true;
}

public static void main(String[] args) {
    try {
        ServerSocket serverSocket = new ServerSocket(5000);
        System.out.println("Server started... Waiting for client.");

        Socket socket = serverSocket.accept();
        System.out.println("Client connected.");

        DataInputStream din = new DataInputStream(socket.getInputStream());
        DataOutputStream dout = new DataOutputStream(socket.getOutputStream());

        int number = din.readInt();
        System.out.println("Received number: " + number);

        if (isPrime(number)) {
            dout.writeUTF(number + " is a PRIME number.");
        } else {
            dout.writeUTF(number + " is NOT a prime number.");
        }

        din.close();
        dout.close();
        socket.close();
        serverSocket.close();

    } catch (Exception e) {
        System.out.println(e);
    }
}}

Client Program (PrimeClient.java)

import java.net.*; 

import java.io.;
import java.util.Scanner;

public class PrimeClient {
public static void main(String[] args) {
    try {
        Socket socket = new Socket("localhost", 5000);

        DataInputStream din = new DataInputStream(socket.getInputStream());
        DataOutputStream dout = new DataOutputStream(socket.getOutputStream());

        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int num = sc.nextInt();

        dout.writeInt(num);

        String result = din.readUTF();
        System.out.println("Server Response: " + result);

        din.close();
        dout.close();
        socket.close();

    } catch (Exception e) {
        System.out.println(e);
    }
}
}

Q.B Write a java program using applet for bouncing ball, for each bounce color of ball should change randomly.

package Multithread;

import javax.swing.; import java.awt.;
import java.util.Random;

public class BouncingBallSwing extends JPanel implements Runnable {
int x = 50, y = 50;
int dx = 5, dy = 5;
int radius = 30;

Thread t;
Color ballColor;
Random rand = new Random();

public BouncingBallSwing() {
    ballColor = randomColor();
    t = new Thread(this);
    t.start();
}

@Override
public void run() {
    try {
        while (true) {

            x += dx;
            y += dy;

            if (x <= 0 || x + radius >= getWidth()) {
                dx = -dx;
                ballColor = randomColor();
            }

            if (y <= 0 || y + radius >= getHeight()) {
                dy = -dy;
                ballColor = randomColor();
            }

            repaint();
            Thread.sleep(30);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.setColor(ballColor);
    g.fillOval(x, y, radius, radius);
}

Color randomColor() {
    return new Color(rand.nextInt(256),
                     rand.nextInt(256),
                     rand.nextInt(256));
}

public static void main(String[] args) {
    JFrame frame = new JFrame("Bouncing Ball");
    BouncingBallSwing panel = new BouncingBallSwing();

    frame.add(panel);
    frame.setSize(500, 400);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
}
}