This tutorial is about creating a chat application using java RMI , Socket connection and java swing .This is the first part of this two part tutorial series . First let’s take a look at the functionalities we will be creating in this chat application.
This chat application will have two parts ( client and server ) . The server will be running as rmi server. Whenever a client connects to server , it will first authenticate the client (client can register himself on the server ) After successful authentication , the client will be shown friend’s list , so that he can chat to his friends. Whenever a friend becomes online or offline , the client is notified and friends list changes dynamically .
Server stores user list and friends list in it's internal database. When the client connects to rmi server , it provides it’s ip also which is saved by rmi server. When a client start chat with online friend , the rmi server issues a remote call to start a socket connection to transfer chat messages . So rmi server here does not store or save chat . The chat messages are transferred directly between the clients by using socket connection between them.
In this part of tutorial , we will create a basic gui using java swing.
so these are our model classes :
Post your comments and suggestions !!
/**
* Application Name :- Let's Chat
*
* @(#)ClientApplication.java
*
*
* @author abhishek somani
* @version 1.00 2008/4/7
*
* Providing the Main userInterface or the Login window for the user
* to use this application
*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class ClientApplication extends JFrame implements ActionListener ,MouseListener //, MouseMotionListener
{
// public and private variables of the class
private JTextField username;
private JPasswordField password;
private JLabel user, pass, error, logo, forgotpassword, register;
private JButton enterBtn;
private URL url;
public JPanel Ippanel , Serveranspanel , buttonpannel, registerpanel, forgotpasswordpanel;
public JPanel passwordpannel, usrnamepannel, usrfieldpannel, passfieldpannel, btnpannel, errorpannel;
WindowUtilities Look;
Toolkit kit;
Container contentpane;
private int screenheight,screenwidth;
private Login obj;
final Color COLOR_NORMAL = Color.BLUE;
final Color COLOR_HOVER = Color.RED;
final Color COLOR_ACTIVE = COLOR_NORMAL;
final Color COLOR_BG_NORMAL = Color.LIGHT_GRAY;
final Color COLOR_BG_ACTIVE = Color.LIGHT_GRAY;
Color mouseOutDefault;
// main class for just checking the frame without any other connection
public static void main(String [] args)
{
ClientApplication f = new ClientApplication();
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public ClientApplication()
{
// Look and feel class of window utility
Look = new WindowUtilities();
Look.setNativeLookAndFeel();
addWindowListener(new ExitListener());
// getting the Dimension of the Screen from system
// in which this application is running
kit = Toolkit.getDefaultToolkit();
Dimension screensize = kit.getScreenSize();
screenheight = screensize.height;
screenwidth = screensize.width;
//setting the frame on the right hand side corner of the screen
setSize(screenwidth/4 , (screenheight-50));
setLocation((screenwidth-screenwidth/4) , 0);
setResizable(true);
setVisible(true);
contentpane = getContentPane();
contentpane.setLayout(new GridLayout(3,1));
// setting the font for any text field of frame
java.awt.Font font = new java.awt.Font("Dialog",Font.BOLD,14);
// creating one of the main panel
Ippanel = new JPanel();
Ippanel.setBorder(BorderFactory.createTitledBorder("Login"));
Ippanel.setLayout(new GridLayout(6,1));
// creating and adding username label in usernamepanel
usrnamepannel = new JPanel();
user = new JLabel("Username: ");
user.setFont(font);
usrnamepannel.add(user,BorderLayout.CENTER);
Ippanel.add(usrnamepannel, BorderLayout.CENTER);
// creating and adding username textfield in usrfieldpanel
usrfieldpannel = new JPanel();
usrfieldpannel.add(username = new JTextField(20), BorderLayout.CENTER);
Ippanel.add(usrfieldpannel, BorderLayout.CENTER);
// creating and adding password label in passwordpanel
passwordpannel = new JPanel();
pass = new JLabel("Password: ");
pass.setFont(font);
passwordpannel.add(pass, BorderLayout.CENTER);
Ippanel.add(passwordpannel,BorderLayout.CENTER);
// creating and adding password textfield in passfieldpanel
passfieldpannel = new JPanel();
passfieldpannel.add(password = new JPasswordField(20),BorderLayout.CENTER );
Ippanel.add(passfieldpannel, BorderLayout.CENTER);
// error label in case of username and password doesn't match
errorpannel = new JPanel();
error = new JLabel("Username and Password doesn't match");
error.setFont(font);
error.setVisible(false);
error.setForeground(Color.RED);
error.setOpaque(true);
errorpannel.add(error,BorderLayout.CENTER);
Ippanel.add(errorpannel, BorderLayout.CENTER);
// creating and adding login button in btnpanel
btnpannel = new JPanel();
enterBtn = new JButton("Login");
enterBtn.setFont(font);
btnpannel.add(enterBtn, BorderLayout.CENTER);
Ippanel.add(btnpannel, BorderLayout.CENTER);
// adding logo of the Let's chat to the frame
Serveranspanel = new JPanel();
Serveranspanel.setBorder(BorderFactory.createLineBorder (Color.blue, 2));
Serveranspanel.setBackground(Color.CYAN);
ImageIcon letchaticon = new ImageIcon("images/llo.jpg");
logo = new JLabel();
logo.setIcon(letchaticon);
logo.setToolTipText("Welcome to Let's Chat Application");
Serveranspanel.add(logo);
// creating and adding register label
registerpanel = new JPanel();
register = new JLabel("Register");
register.setFont(font);
register.addMouseListener(this);
registerpanel.add(register, BorderLayout.CENTER);
// creating and adding forgetpassword label
forgotpasswordpanel = new JPanel();
forgotpassword = new JLabel("Forgot Password");
forgotpassword.setFont(font);
forgotpassword.addMouseListener(this);
forgotpasswordpanel.add(forgotpassword, BorderLayout.CENTER);
buttonpannel = new JPanel();
buttonpannel.setLayout(new GridLayout(8,1));
buttonpannel.add(registerpanel,BorderLayout.CENTER);
buttonpannel.add(forgotpasswordpanel,BorderLayout.CENTER);
// adding all the pannels to ContentPane
contentpane.add(Serveranspanel);
contentpane.add(Ippanel);
contentpane.add(buttonpannel);
// add Action listener to the login button
enterBtn.addActionListener(this);
enterBtn.setToolTipText("Please enter username and password then press this button");
}
// action againist login button click
public void actionPerformed(ActionEvent ae)
{
//System.out.println("Action Performed");
boolean flag;
if (ae.getActionCommand().equals("Login"))
{
JButton clickedbutton = (JButton)ae.getSource();
if(clickedbutton == enterBtn)
{
String us = username.getText();
String ps = password.getText();
// validating either username and password fields are not empty
if(us.equals(""))
{
error.setText("Please enter the username");
error.setVisible(true);
}
else if(ps.equals(""))
{
error.setText("Please enter the password");
error.setVisible(true);
}
else
{
obj=new Login();
try
{
//Get an instance of InetAddress for the local computer
InetAddress inetAddress = InetAddress.getLocalHost();
//Get a string representation of the ip address
String ipAddress = inetAddress.getHostAddress();
//Print the ip address
//System.out.println(ipAddress);
flag = obj.login(us,ps,ipAddress);
if(flag == true)
{
//System.out.println("Frame Repainted");
dispose();
}
if(flag == false)
{
error.setText("Username and Password doesn't match");
error.setVisible(true);
}
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
}
}
// action against mouse click on register to open the register for
// let's chat application and forgetpassword for existing user who
// forget their passwords
public void mouseClicked(java.awt.event.MouseEvent me)
{
if(me.getSource() instanceof JLabel)
{
JLabel clicked = (JLabel)(me.getSource());
setForeground(COLOR_ACTIVE);
mouseOutDefault = COLOR_ACTIVE;
if(clicked == register)
{
//System.out.println("Register Clicked");
//you can create a simple web app where user where user can register themselves and give link here
String url = "http://resigisetrurl/chat/register.html";
String os = System.getProperty("os.name").toLowerCase();
Runtime rt = Runtime.getRuntime();
try
{
if (os.indexOf( "win" ) >= 0)
{
String[] cmd = new String[4];
cmd[0] = "cmd.exe";
cmd[1] = "/C";
cmd[2] = "start";
cmd[3] = url;
rt.exec(cmd);
}
else if (os.indexOf( "mac" ) >= 0)
{
rt.exec( "open " + url);
}
else
{
//prioritized 'guess' of users' preference
String[] brwsers = {"epiphany", "firefox", "mozilla"};
StringBuffer cmd = new StringBuffer();
for (int i=0; i= 0)
{
String[] cmd = new String[4];
cmd[0] = "cmd.exe";
cmd[1] = "/C";
cmd[2] = "start";
cmd[3] = url;
rt.exec(cmd);
}
else if (os.indexOf( "mac" ) >= 0)
{
rt.exec( "open " + url);
}
else
{
//prioritized 'guess' of users' preference
String[] brwsers = {"epiphany", "firefox", "mozilla", "konqueror", "netscape","opera","links","lynx"};
StringBuffer cmd = new StringBuffer();
for (int i=0; i<brwsers.length; i++)
cmd.append( (i==0 ? "" : " || " ) + brwsers[i] +" \"" + url + "\" ");
rt.exec(new String[] { "sh", "-c", cmd.toString() });
}
}
catch(Exception e)
{
System.out.println("error occured in opening browser");
}
}
}
}
public void mouseExited(MouseEvent me)
{
setForeground(mouseOutDefault);
setBackground(COLOR_BG_NORMAL);
Cursor cursor = getCursor();
setCursor(cursor.getDefaultCursor());
//System.out.println("Mouse Exited");
}
public void mouseReleased(MouseEvent me)
{
//System.out.println("Mouse Released");
}
public void mousePressed(MouseEvent me)
{
mouseOutDefault = COLOR_ACTIVE;
//System.out.println("Mousepressed");
}
public void mouseEntered(MouseEvent me)
{
setForeground(Color.RED);
setBackground(COLOR_BG_ACTIVE);
Cursor cursor = getCursor();
setCursor(cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
// System.out.println("Mouse Entered");
}
}
Here , we have created Register and forgot password buttons , which will open browser and point to your web app , where you have defined mechanism for registering a user and forgot password mechanism. Other part of code is quite self explanatory where we have created panels and arranged them in proper way .
