Simple And Advanced Java Programs

The Given Program that accepts a login name and password from the user. The application contains two buttons. The 'Log In 'button when clicked, checks the user name and password entered in the text box, and the ‘cancel’ button will terminate the application. The user is excepted to enter both username and password before clicking the Log In button.
If the correct username and password is entered by the user, then a new frame is opened where product rate and quantity are displayed. The product is a combo box which has 5 options :

Product 1
Product 2
Product 3
Product 4
Product 5

On selecting product 1 the rate displayed on the text field will be 150, similarly product 2, product 3, product 4 and product5 will display rate as 250, 350, 450 and 550 respectively. The rate text field will be Editable false i.e. the contents of rate box cannot be edited. The select the respective Quantity for the product. On clicking the enter button again a new frame will be opened where all the components are editable false and a new text field is displayed where the total amount is displayed. In addition to this a menu bar called ‘file’ is also displayed on the container which has two menu items new and exit, on clicking new the log in page is opened and on clicking exit the application is terminated.

The username and password in the given program
username: javapgms
password: lionel
*/

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class Admin extends JFrame implements ActionListener
{
JTextField jft1,jft2;
JButton b1,b2;
Container cont;

Admin()
{
cont = getContentPane();
cont.setLayout(null);

JLabel jl1=new JLabel("Username:");
cont.add(jl1);
jl1.setBounds(20,30,100,20);

jft1=new JTextField();
cont.add(jft1);
jft1.setBounds(100,30,200,30);

JLabel jl2=new JLabel("Password:");
cont.add(jl2);
jl2.setBounds(20,80,100,20);

jft2=new JTextField();
cont.add(jft2);
jft2.setBounds(100,80,200,30);

b1=new JButton("Sign In");
cont.add(b1);
b1.setBounds(75,150,100,30);
b1.addActionListener(this);

b2=new JButton("Cancel");
cont.add(b2);
b2.setBounds(200,150,100,30);
b2.addActionListener(this);
}

public static void main(String args[])
{
Admin admn=new Admin();
admn.setSize(400,400);
admn.setVisible(true);
}

public void actionPerformed(ActionEvent ae)
{
if(ae.getSource() == b2)
System.exit(0);

String user=jft1.getText();
String password=jft2.getText();

if(user.equals("javapgms")&&password.equals("lionel"))
{
Admin2 jf=new Admin2();
jf.setSize(400,300);
jf.setVisible(true);
}
else
JOptionPane.showMessageDialog(cont,"Invalid Details","Lionel's Message",

JOptionPane.ERROR_MESSAGE);
}
}

class Admin2 extends JFrame implements ActionListener,ItemListener
{
JComboBox jc;
JTextField ft1,ft2,ft3;
JButton B1;
String z,t;
Admin2()
{
Container cont=getContentPane();
cont.setLayout(null);

JLabel l1=new JLabel("Product:");
cont.add(l1);
l1.setBounds(20,30,100,20);

jc=new JComboBox();
jc.addItem("product1");
jc.addItem("product2");
jc.addItem("product3");
jc.addItem("product4");
jc.addItem("product5");
cont.add(jc);
jc.setBounds(80,30,200,20);
jc.addItemListener(this);

JLabel l2=new JLabel("Rate:");
cont.add(l2);
l2.setBounds(20,60,50,20);

ft1=new JTextField();
cont.add(ft1);
ft1.setEditable(false);
ft1.setBounds(80,60,50,20);

JLabel l3=new JLabel("Quantity:");
cont.add(l3);
l3.setBounds(20,90,100,20);

ft2=new JTextField();
cont.add(ft2);
ft2.setBounds(80,90,50,20);

B1=new JButton("Enter");
cont.add(B1);
B1.setBounds(150,150,100,30);
B1.addActionListener(this);
}

public void actionPerformed(ActionEvent ne)
{
String m=ft1.getText();
int a=Integer.parseInt(m);
String n=ft2.getText();
int b=Integer.parseInt(n);
z=jc.getSelectedItem().toString();

int tot=a*b;
t = String.valueOf(tot);

Admin3 admn3=new Admin3(z,m,n,t);
admn3.setSize(400,400);
admn3.setVisible(true);
}

public void itemStateChanged(ItemEvent me)
{
z=jc.getSelectedItem().toString();
if(z.equals("product1"))
ft1.setText("150");
else if(z.equals("product2"))
ft1.setText("250");
else if(z.equals("product3"))
ft1.setText("350");
else if(z.equals("product4"))
ft1.setText("450");
else if(z.equals("product5"))
ft1.setText("550");
}
}

class Admin3 extends JFrame implements ActionListener
{
JTextField ftf1,ftf2,ftf3,ftf0;
String x,y,z,q;
int l,m,n,tot1;
JMenuBar bar= new JMenuBar();
JMenuItem it1,it2;

Admin3(String l,String m,String n,String t)
{
Container cont=getContentPane();
cont.setLayout(null);

JMenu file = new JMenu ("File");
it1 = new JMenuItem("New");
it2 = new JMenuItem("Exit");
file.add(it1);
file.add(it2);

it1.addActionListener(this);
it2.addActionListener(this);

bar.add(file);
setJMenuBar(bar);

JLabel lb1=new JLabel("Product:");
cont.add(lb1);
lb1.setBounds(20,30,100,20);

ftf0=new JTextField();
ftf0.setEditable(false);
ftf0.setBounds(80,30,200,20);
cont.add(ftf0);
ftf0.setText(l);

JLabel lb2=new JLabel("Rate:");
cont.add(lb2);
lb2.setBounds(20,60,50,20);

ftf1=new JTextField();
cont.add(ftf1);
ftf1.setEditable(false);
ftf1.setBounds(80,60,50,20);
ftf1.setText(m);

JLabel lb3=new JLabel("Quantity:");
cont.add(lb3);
lb3.setBounds(20,90,100,20);

ftf2=new JTextField();
cont.add(ftf2);
ftf2.setEditable(false);
ftf2.setBounds(80,90,50,20);
ftf2.setText(n);

JLabel lb4=new JLabel("Total Amt");
cont.add(lb4);
lb4.setBounds(20,120,100,20);

ftf3=new JTextField();
cont.add(ftf3);
ftf3.setEditable(false);
ftf3.setBounds(80,120,100,20);
ftf3.setText(t);
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource()==it1)
{
Admin admn=new Admin();
admn.setSize(400,400);
admn.setVisible(true);
}

if(ae.getSource()==it2)
System.exit(0);
}
}

/* Kindly leave your useful comments or suggesstin if any. */