Wednesday, April 8, 2015

Java Program for Client Server Ping

PingClient.java



import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Random;

/*
* Server to process ping requests over UDP. java PingClient host port
*/
public class PingClient
{

public static void main(String[] args) throws Exception
{
// Get command line argument.
if (args.length != 2) {
System.out.println("Required arguments: host port");
return;
}

String ServerName =args[0];   
int port = Integer.parseInt(args[1]);


// Create a datagram socket for receiving and sending UDP packets
// through the port specified on the command line.
DatagramSocket socket = new DatagramSocket();
InetAddress IPAddress =InetAddress.getByName(ServerName);
// Processing loop.

// You should write the client so that it sends
// 10 ping requests to the server, separated by
// approximately one second.

for(int i=0;i<10;i++){

// Create a datagram packet to hold outgoing UDP packet.


//Each message contains
// a payload of data that includes the keyword PING,
// a sequence number, and a timestamp.
long SendTime = System.currentTimeMillis();
String Message = "Ping "+ i + " " + SendTime + "\n";
DatagramPacket request =
new DatagramPacket(Message.getBytes(), Message.length(),IPAddress,port );
socket.send(request);
DatagramPacket reply =
new DatagramPacket(new byte[1024], 1024);

socket.setSoTimeout(1000);

try
{
socket.receive(reply);
}catch(IOException E)
{

}

Thread.sleep(1000);

}

// After sending each packet, the client waits up
// to one second to receive a reply.
// If one seconds goes by without a reply from the server,
// then the client assumes that its packet or the
// server's reply packet has been lost in the network.

}

/*
* Print ping data to the standard output stream.
*/
private static void printData(DatagramPacket request) throws Exception
{
// Obtain references to the packet's array of bytes.
byte[] buf = request.getData();

// Wrap the bytes in a byte array input stream,
// so that you can read the data as a stream of bytes.
ByteArrayInputStream bais = new ByteArrayInputStream(buf);

// Wrap the byte array output stream in an input stream reader,
// so you can read the data as a stream of characters.
InputStreamReader isr = new InputStreamReader(bais);

// Wrap the input stream reader in a bufferred reader,
// so you can read the character data a line at a time.
// (A line is a sequence of chars terminated by any combination of \r and \n.)
BufferedReader br = new BufferedReader(isr);

// The message data is contained in a single line, so read this line.
String line = br.readLine();

// Print host address and data received from it.
System.out.println(
"Received from " +
request.getAddress().getHostAddress() +
": " +
new String(line) );
}
}


PingServer.java

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

/*
 * Server to process ping requests over UDP.
 */
public class PingServer
{
   private static final double LOSS_RATE = 0.3;
   private static final int AVERAGE_DELAY = 100;  // milliseconds

   public static void main(String[] args) throws Exception
   {
      // Get command line argument.
      if (args.length != 1) {
         System.out.println("Required arguments: port");
         return;
      }
      int port = Integer.parseInt(args[0]);

      // Create random number generator for use in simulating
      // packet loss and network delay.
 Random random = new Random();

      // Create a datagram socket for receiving and sending UDP packets
      // through the port specified on the command line.
      DatagramSocket socket = new DatagramSocket(port);

      // Processing loop.
      while (true) {
         // Create a datagram packet to hold incomming UDP packet.
         DatagramPacket request = new DatagramPacket(new byte[1024], 1024);

         // Block until the host receives a UDP packet.
         socket.receive(request);
       
         // Print the recieved data.
         printData(request);

         // Decide whether to reply, or simulate packet loss.
         if (random.nextDouble() < LOSS_RATE) {
            System.out.println("   Reply not sent.");
            continue;
         }

         // Simulate network delay.
         Thread.sleep((int) (random.nextDouble() * 2 * AVERAGE_DELAY));

         // Send reply.
         InetAddress clientHost = request.getAddress();
         int clientPort = request.getPort();
         byte[] buf = request.getData();
         DatagramPacket reply = new DatagramPacket(buf, buf.length, clientHost, clientPort);
         socket.send(reply);

         System.out.println("   Reply sent.");
      }
   }

   /*
    * Print ping data to the standard output stream.
    */
   private static void printData(DatagramPacket request) throws Exception
   {
      // Obtain references to the packet's array of bytes.
      byte[] buf = request.getData();

      // Wrap the bytes in a byte array input stream,
      // so that you can read the data as a stream of bytes.
      ByteArrayInputStream bais = new ByteArrayInputStream(buf);

      // Wrap the byte array output stream in an input stream reader,
      // so you can read the data as a stream of characters.
      InputStreamReader isr = new InputStreamReader(bais);

      // Wrap the input stream reader in a bufferred reader,
      // so you can read the character data a line at a time.
      // (A line is a sequence of chars terminated by any combination of \r and \n.)
      BufferedReader br = new BufferedReader(isr);

      // The message data is contained in a single line, so read this line.
      String line = br.readLine();

      // Print host address and data received from it.
      System.out.println(
         "Received from " +
         request.getAddress().getHostAddress() +
         ": " +
         new String(line) );
   }
}



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Friday, March 27, 2015

Quine Mc Cluskey Method to simplification of boolean expression

guys this is the perfect tutorial to understand how to simplify the boolean expression using Quine Mc cluskey method
thanks for watching