Multichatserver

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

class  ClientInfo{
String name;
Socket cs;
public ClientInfo(String nm,Socket s)
{
name = nm;
cs = s;
}

}



public class multichatserver {

ServerSocket  ss;
Socket s;
Hashtable list;
PrintStream chatLog;
Vector namevect;


public multichatserver()
{
list = new Hashtable();
namevect = new Vector();
try
{
chatLog = new PrintStream(new FileOutputStream("multichat.log"));
}catch(IOException e)
{
System.out.println("Error opening file");
System.exit(1);
}
  try{
ss = new ServerSocket(2000);
while(true)
{
System.out.println("SERVER READY TO TAKE REQUESTS");
s = ss.accept();
new FileThread(s).start();

}
}catch(IOException ioe)
{
System.out.println("IOException Caught");
}
}


class FileThread extends Thread{

Socket fs;
BufferedReader br;
String name;
public FileThread(Socket s)
{
fs = s;
}
public void run()
{
try
{
InputStream  is = fs.getInputStream();
OutputStream os = fs.getOutputStream();
br = new BufferedReader (new InputStreamReader(is));
while((name = br.readLine())!=null)
{
 if(list.containsKey(name))
 {
  continue;
 }
 else
 {
 ClientInfo cinfo = new ClientInfo(name,fs);
 chatLog.println(name+" Registered from Host:"+fs.getInetAddress().getHostName()+"and IP address:"+fs.getInetAddress().getHostAddress() );
 list.put(name,cinfo);
 Enumeration enumS = list.elements();
 namevect.addElement(name);
 while(enumS.hasMoreElements())
 {
   ClientInfo clinfo =(ClientInfo)enumS.nextElement();
   System.out.println("client name"+clinfo.name);
   new DataOutputStream(clinfo.cs.getOutputStream()).writeInt(1);
   ObjectOutputStream obos = new ObjectOutputStream(clinfo.cs.getOutputStream());
   obos.writeObject(namevect);
   obos.flush();
 }
 new messageThread(name,fs).start();
 System.out.println("Thread Started.");
 break;
 }
  }

   }
  catch(IOException ioe)
  {
  System.out.println("IOException Caught");
  }


}
}

class messageThread extends Thread{
Socket ms;
String name;
public messageThread(String nm,Socket s)
{
ms = s;
name = nm;
}

public void run()
{
InputStream is;
OutputStream os;
BufferedReader br;
String message;
try{
is = ms.getInputStream();
   os = ms.getOutputStream();
   br = new BufferedReader(new InputStreamReader(is));

while((message = br.readLine())!=null)
   {
  System.out.println("message sent from "+ name);
      Enumeration en = list.elements();
  while(en.hasMoreElements())
   {
    ClientInfo clinf = (ClientInfo)en.nextElement();
    if(!clinf.name.equals(name))
    {
     new DataOutputStream(clinf.cs.getOutputStream()).writeInt(0);
   //clinf.ps.println(name+": "+message);
   PrintWriter pw = new PrintWriter(new OutputStreamWriter(clinf.cs.getOutputStream()),true);
   pw.println(name+": "+message);
       }
//clinf.ps.println(name+": "+message);
   }

  }
  System.out.println("out of while loop");

}catch(IOException ioe)
{
list.remove(name);
chatLog.println(name + "Quits.");
return;
}


}

  }




  public static void main(String args[])
  {
 multichatserver mcs = new multichatserver();
  }
}

Multichatclient

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;


public class multichatclient extends Frame implements ActionListener,KeyListener {

Label meslabel;
Vector namevect;
TextField mesg;
Button send,login,exit;
TextArea ta,usrlist;
Panel top,mid,bot;
String message,messg,usr,name;
InputStream is ;
OutputStream os ;
BufferedReader br ;
PrintStream ps ;
Socket s;
public multichatclient(String title)
{
super(title);
initComponents();
setLayout(new BorderLayout());
top = new Panel();
top.setLayout(new GridLayout(1,2));
bot = new Panel();
bot.setLayout(new GridLayout(1,3,5,5));
setSize(500,500);
setBackground(Color.gray);
setForeground(Color.black);
meslabel = new Label("PESAN",Label.RIGHT);
mesg = new TextField(20);
ta = new TextArea("Client: HALLO SEMUA!\n",50,50,TextArea.SCROLLBARS_BOTH);
usrlist = new TextArea("DAFTAR USER",50,20,TextArea.SCROLLBARS_BOTH);
send = new Button("KIRIM");
login = new Button("MASUK");
exit = new Button("KELUAR");
send.setEnabled(false);
top.add(meslabel);
top.add(mesg);
bot.add(login);
bot.add(send);
bot.add(exit);
add(top,BorderLayout.NORTH);
add(bot,BorderLayout.SOUTH);
add(ta,BorderLayout.CENTER);
add(usrlist,BorderLayout.EAST);
send.addActionListener(this);
mesg.addKeyListener(this);
login.addActionListener(this);
exit.addActionListener(this);
try
{
s = new Socket("192.168.30.10",2000);
is = s.getInputStream();
os = s.getOutputStream();
ps = new PrintStream(os);
 } catch(IOException ie)
 {
 ie.printStackTrace();
 }
 }

public void actionPerformed(ActionEvent ae)
{
Button btn = (Button)ae.getSource();
byte reply = 0;
if(btn == login)
{
loginDialog ld = new loginDialog(this);
ld.show();
usr = ld.user;
//usrlist.append("\n"+usr);
//System.out.println("USER NAME:"+ usr);
ps.println(usr);
ps.flush();
login.setEnabled(false);
send.setEnabled(true);
new MessageReader().start();
}
if(btn == send)
{
 String txt = mesg.getText();
 ps.println(txt);
 ps.flush();
 ta.append(txt+"\n");
          mesg.setText("");
      }
if(btn == exit)
{
try
{
s.close();
}catch(IOException ioe)
{
}
System.exit(1);
}


}
public void keyPressed(KeyEvent ke)
{
}
public void keyReleased(KeyEvent ke)
{
}
public void keyTyped(KeyEvent ke)
{

}


    public void initComponents()
    {
addWindowListener(new WindowAdapter(){
public void  windowClosing(WindowEvent we)
{
setVisible(false);
}
});


}


 class MessageReader extends Thread {
int check=0;
ObjectInputStream objis;
DataInputStream dis;
String msg;
public void run()
{
 try
  {
  while(true)
  {
  dis = new DataInputStream(is);
  check = dis.readInt();
  if(check == 1)
  {
    objis = new ObjectInputStream(is);
    namevect =(Vector)objis.readObject();
    System.out.println("No of users in list:"+namevect.size());
    Enumeration en = namevect.elements();
    usrlist.setText("User List");
    while(en.hasMoreElements())
     {
       name = (String)en.nextElement();
       System.out.println("name added to list:"+name);
       usrlist.append("\n"+name);
     }
     System.out.println("check: "+check);
      }
      else
      {
  br = new BufferedReader(new InputStreamReader(is));
  msg = br.readLine();
  ta.append(msg+"\n");
  while((msg = br.readLine())!=null)
  {
String mymsg = msg;
mymsg = mymsg.substring(4,mymsg.length()-1);
System.out.println("message received is:"+mymsg);
//mymsg = "hello";
JOptionPane.showMessageDialog(null,mymsg,"Message Received",JOptionPane.INFORMATION_MESSAGE);
ta.append(mymsg+"\n");
System.out.println("check: "+check);
  }

  }

  }

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



      }
 }






  public static void main(String s[])
    {
      multichatclient mcc= new multichatclient("Messenger");
      mcc.setVisible(true);
      mcc.show();
    }

}

class  loginDialog extends Dialog implements ActionListener{
Label loginname;
TextField logintext;
Button okay;
Panel top,central;
String user;

loginDialog(Frame parent)
{
super(parent,"User Login",true);
setSize(400,100);
setResizable(false);
setFont(new Font("ComicSans",Font.BOLD|Font.ITALIC,15));
loginname = new Label("Enter Login:",Label.RIGHT);
logintext = new TextField(15);
okay = new Button("OK");
//okay.setBounds(10,10,20,20);
top = new Panel();
central = new Panel();
central.setLayout(new FlowLayout());
top.setLayout(new GridLayout(1,2,5,5));
top.add(loginname);
top.add(logintext);
central.add(okay);
add(central,BorderLayout.CENTER);
add(top,BorderLayout.NORTH);
okay.addActionListener(this);
}

public void actionPerformed(ActionEvent ae)
{
user = logintext.getText();
dispose();
}

}

//TUGAS KEREN 1//

import java.net.*;  //untuk mendukung pemrograman socket/jaringan


public class TugasKeren {  //deklarasi class

public static void main (String[] args) { //deklarasi main method

InetAddress address = null; // untuk mendapatkan alamat IP maupun nama host suatu komputer

try { //untuk mengecek apakah ada kesalahan pada program

address = InetAddress.getByName("10.1.1.1"); //mengambil informasi IP dari nama yang diberikan
boolean reachable = address.isReachable(10000);

System.out.println(" Is host reach able? " + reachable); // mencetak angka atau karakter pada layar
}
catch (Exception e) { //tangkap eksepsi dari hasil "try"
e.printStackTrace();
}
}
}





//TUGAS OK 2//

import java.net.*; //berisikan kelas-kelas untuk pemograman jaringan

public class TugasOK { //menciptakan kelas yang bernama TugasOK

public static void main (String[]args){//void utama dalam java

try{//Try Catch ini adalah salah satu fitur dari Java untuk menangkap eksepsi atau kesalahan

InetAddress address = InetAddress.getByName("IP_ADDRESS");//pengambilan alamat internet sesuai alamat yang diisikan
NetworkInterface ni= NetworkInterface.getByInetAddress(address);

if(ni!=null){//menseleksi ni tidak sama dengan null
byte[]mac =ni.getHardwareAddress();//menciptakan aray dengan nama mac

if(mac!=null){//menseleksi mac tidak sama dengan null
for(int i=0;i<mac.length; i++){//perulangan mencari mac
System.out.format("%02X%s",mac[i],(i<mac.length -1)?"-":"");//mencetak
}
}

else {
System.out.println("Address is not accessible.");//mencetak "Address is not accessible." jika alamat tidak dapat diakses
}
}

else{
System.out.println("network interface is not found.");//mencetak "network interface is not found." antarmuka jaringan tidak ditemukan
}
}

catch(UnknownHostException e){//statement blok yang menangani exception (perkecualian)
e.printStackTrace();

}

catch(SocketException e){//statement blok yang menangani exception (perkecualian)
e.printStackTrace();

}
}
}



//TUGAS HEBAT 3//

import java.io.IOException;  //menjelaskan bahwa kita akan menggunakan class IOException yang berada di java.io package
import java.net.InetAddress;  //menjelaskan bahwa kita akan menggunakan class InetAddress yang berada di java.net package
import java.net.Socket;  //menjelaskan bahwa kita akan menggunakan class Socket yang berada di java.io package


public class TugasHebat{//menciptakan kelas yang bernama TugasHebat

public static void main(String []args) throws Exception{/* void utama dari program java TugasKeren dengan
throws Exception menghandle error yang terjadi dengan melempar (throw exception). Keyword yang digunakan adalah throw*/

String host ="localhost";//mengisikan host
InetAddress inetAddres =InetAddress.getByName(host);//pengambilan alamat internet sesuai alamat host yang diisikan

String hostName=inetAddres.getHostName();//mengambil nama host
for(int port=0; port<=65535; port++)//perulanagan mencari port
{

try{//Try Catch ini adalah salah satu fitur dari Java untuk menangkap eksepsi atau kesalahan
Socket socket=new Socket(hostName,port);/*Tentukan IP Address atau Hostname mesin server dan nomor port
dimana aplikasi server berjalan */

String text =hostName + "is listening on port "+ port;//mengisi String text dengan hostName + "is listening on port "+ port
System.out.println(text);//mencetak isi dari string text ke layar
socket.close();//untuk menutup socket
}
catch(IOException e){
String s= hostName + "is not listenig on port "+ port;//mengisi String s dengan hostName + "is listening on port "+ port
System.out.println(s);//mencetak isi dari variabel s ke layar
}
}
}
}