Main.java

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
 
import java.util.*;
import java.io.*;
import java.lang.*;
import java.util.Date;

import java.text.*;

import java.util.Calendar;
import java.util.Date;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import java.sql.*; 
 

class myip
{




Pattern macpt = null;


public  String getMac(String ip) 
{

    // Find OS and set command according to OS
    String OS = System.getProperty("os.name").toLowerCase();

    String[] cmd;
    if (OS.contains("win")) {
        // Windows
        macpt = Pattern
                .compile("[0-9a-f]+-[0-9a-f]+-[0-9a-f]+-[0-9a-f]+-[0-9a-f]+-[0-9a-f]+");
        String[] a = { "arp", "-a", ip };
        cmd = a;
    } else {
        // Mac OS X, Linux
        macpt = Pattern
                .compile("[0-9a-f]+:[0-9a-f]+:[0-9a-f]+:[0-9a-f]+:[0-9a-f]+:[0-9a-f]+");
        String[] a = { "arp", ip };
        cmd = a;
    }

    try {
        // Run command
        Process p = Runtime.getRuntime().exec(cmd);
        p.waitFor();
        // read output with BufferedReader
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                p.getInputStream()));
        String line = reader.readLine();

        // Loop trough lines
        while (line != null) {
            Matcher m = macpt.matcher(line);

            // when Matcher finds a Line then return it as result
            if (m.find()) {
                System.out.println("Found");
                System.out.println("MAC: " + m.group(0));
                return m.group(0);
            }

            line = reader.readLine();
        }

    } catch (IOException e1) {
        e1.printStackTrace();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    // Return empty string if no MAC is found
    return "";
}

}

public class Main {
    public static void main(String args[]) throws UnknownHostException{
 
        Vector<String> Available_Devices=new Vector<>(); // stores the list of available/connected devices


  ArrayList <String> name = new ArrayList<String>();

        String myip=InetAddress.getLocalHost().getHostAddress(); // IP of the PC in which the code is running/localhost
        if(myip.equals("127.0.0.1")){
            System.out.println("This PC is not connected to any network!");
        }
        else {
            String mynetworkips=new String(); // just a new string to store currently scanning ip
 
            // this loop finds the right most '.' of this PC's IP
            // suppose your PC's IP is 192.168.0.101, this loop finds the index of the '.' just before '101'
            // and as soon as it finds the '.', it creates a new string(actually substring of this PC's IP) starting at
            // index 0 and ending at index containing character '.' and exits from the loop
            // So here, if the IP was 192.168.0.101,mynetworkips will have the value "192.168.0."
            for(int i=myip.length()-1;i>=0;--i){
                if(myip.charAt(i)=='.'){
                    // .substring(i,j) returns a string starting from index i and ending at index j-1,so in order to
                    // include '.' , i put (i+1)
                    mynetworkips=myip.substring(0,i+1);
                    break;
                }
            }
 
            System.out.println("My Device IP: " + myip+"\n"); // Shows this PC's IP
 
            System.out.println("Search log:");
 
            // (loop bellow->) just add the string representation of i and add it to mynetworkips to get full IP
            // for example, when i=1 the ip will be(if mynetworkips is "192.168.0.") 192.168.0.1,
            // and then at next iteration it'll be 192.168.0.1
            // this means tis loop iterates over all possible ips and show you which one is available or not.
 
            // you can change i's range if you know that your network's IPs start from another
            // point(probably for most router(if not customized) , it will start from 192.168.0.100)
            for(int i=1;i<=20;++i){
                try {
                    // Create an InetAddrss object with new IP
                    InetAddress addr=InetAddress.getByName(mynetworkips + new Integer(i).toString());
 
                    if (addr.isReachable(1000))
{ // See if it is reachable or simply available(check time is 1s=1000ms)
                      //  System.out.println("Available: " + addr.getHostAddress()); // show that it is available
                        Available_Devices.add(addr.getHostAddress()); // if available, add it to final list
                         
                        name.add(addr.getHostName()); 

						
						
						
 

                    }
                    else
					{
						
						System.out.println(" not connect "+mynetworkips +i);
					}
						
					
 
                }catch (IOException ioex){
                    // nothing to do, just catch it if something goes wrong
                }
            }
 
            // print the list of available devices
            System.out.println("\nAll Connected devices(" + Available_Devices.size() +"):");
			
			
			
DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
	Date date = new Date();
	String datetime =  "" +dateFormat.format(date); 
	
			
            for(int i=0;i<Available_Devices.size();++i)
{

 System.out.println(Available_Devices.get(i)+"-"+ name.get(i));

  //  InetAddress ip =   InetAddress.getByName(""+Available_Devices.get(i) +"-"+ );

//InetAddress ip = InetAddress.getByName("192.168.0.105");

                try
                {

          
               
myip ob = new myip();

String ipad = Available_Devices.get(i).toString();
System.out.println(" mac:"+ob.getMac(ipad));





	
	String mac = ""+ob.getMac(ipad);
	
	String dname = ""+name.get(i).toString();
	
	
			Class.forName("com.mysql.jdbc.Driver");  
Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/wifi","root","");  

Statement st = con.createStatement();
			
			ResultSet r= st.executeQuery("select mac from student  where   mac ='"+mac+"'   ");


String status="invalid";
if(r.next())
{
status="valid";
System.out.println(" NAME :"+ r.getString(1));

}


st.executeUpdate("insert into devices values('"+ipad+"','"+dname+"','"+mac+"','"+datetime+"','"+status+"' ) ");

	
	
			
			
			

con.close();

                }
               catch(Exception ee)
             {
System.out.println("mac error"+ee);
              }
			

}
        }
    }
}