Java practical

1. Program to generate Fibonacci series

import java.io.*;
import java.util.*;
public class Fibonacci
{
public static void main(String[] args)
{
DataInputStream reader = new DataInputStream((System.in));
int f1=0,f2=0,f3=1;
try
{

System.out.print("Enter value of n: ");
String st = reader.readLine();
int num = Integer.parseInt(st);

for(int i=1;i<=num;i++)
{
System.out.println("tt"+f3+"tnt");
f1=f2;
f2=f3;
f3=f1+f2;
}
}
catch(Exception e)
{
System.out.println("wrong input");
}
}
}

2. Program to take two numbers as input from command line interface and display their sum

Coding:
class Sum
{
public void add(int a,int b)
{
int c;
c=a+b;
System.out.print("tttnnThe sum of two no is = "+c);
System.out.println("nnn");
}
}

class SMain
{
public static void main(String arg[])
{
Sum obj1=new Sum();
int x,y;
String s1,s2;
s1=arg[0];
s2=arg[1];
x=Integer.parseInt(s1);
y=Integer.parseInt(s2);
obj1.add(x,y);
}
}

3. Use of array in java
Coding:
class Person
{
String name[];
int age[];
}

class PersonMain
{
{

Person obj=new Person();

obj.name=new String[6];
obj.age=new int[6];
obj.name[0]="Neha";
obj.age[0]=19;

obj.name[1]="manpreet";
obj.age[1]=19;

obj.name[2]="rahul";
obj.age[2]=23;

obj.name[3]="yuvraj";
obj.age[3]=12;

obj.name[4]="kombe";
obj.age[4]=19;

obj.name[5]="tony";
obj.age[5]=19;

for(int i=0;i<4;i++)
System.out.println(obj.name[i]);
{
for(int j=0;j<4;j++)
System.out.println(obj.age[j]);
}
}
}

4. Create a class customer having three attributes name, bill and id. Include appropriate
methods for taking input from customer and displaying its values
Coding: import java.io.DataInputStream;
class Customer
{
public static void main(String arf[])
{
DataInputStream myinput=new DataInputStream(System.in);
String name;
int bill=0,id=0;
try
{
System.out.println("enter name of customer");
name=myinput.readLine();

System.out.println("enter bill");
bill=Integer.parseInt(myinput.readLine());

System.out.println("enter id");
id=Integer.parseInt(myinput.readLine());

System.out.println("name of customer is"+name);
System.out.println("bill of customer"+bill);
System.out.println("id of customer"+id);
}
catch(Exception e)
{
System.out.println("wrong input error!!!");
}
}
}

5. To show the concept of method overloading
Coding:

class Addition//FUNCTION OVERLOADING

{

public int add(int a,int b)

{

int c=a+b;

return (c);

}

public float add(float a,float b)

{

float c=a+b;

return (c);

}

public double add(double a,double b)

{

double c=a+b;

return (c);

}

}

class AddMain

{


{

Addition obj=new Addition();

System.out.println(obj.add(20,30));

System.out.println(obj.add(100.44f,20.54f));

System.out.println(obj.add(1380.544,473.56784));

}

}

6. To count no. of object created of a class
class Demo//OBJECT CREATION

{

private static int count=0;

public Demo()

{

System.out.println("i am from demo");

count++;

System.out.println("object created is"+count);

}

}

class DemoMains

{

public static void main(String args[])

{

Demo obj1=new Demo();



}

}

7. To show concept of multilevel inheritance
Coding:
class A
{
private int num1,num2,sum;
public void set(int x,int y)
{

num1=x;
num2=y;
sum=num1+num2;
}
public int get1()
{
return(sum);
}
}
class B extends A
{
public void display()
{
System.out.println("sum of two numbers is"+get1());
}
}
class C extends B
{
private double sqr;
public void sqrs()
{
sqr=java.lang.Math.sqrt(get1());
System.out.println("square root of sum is"+sqr);
}
}
class ABCMain
{
{
C obj1=new C();
obj1.set(100,200);
System.out.println("first number is 100");
System.out.println("second number is 200");
obj1.display();
obj1.sqrs();
}
}

8. To show concept of method overriding
Coding:

class Demo

{

private static int count=0;

public Demo()

{

System.out.println("i am from demo");

count++;

System.out.println("object created is"+count);

}

public String toString()

{

return("method overridding");

}

}

class MethodOverride

{


{




System.out.println("overriding toString methodnnttoverriden message=: "+obj1.toString());

}

}

9. Create a class that will at least import two packages and use the method defined in the
classes of those packages.
Coding:
MyApplet.java:
import java.awt.*;
import java.applet.*;
public class MyApplet extends Applet
{
public void paint(Graphics g)
{

g.drawLine(400,100,100,400);
}
}
Ex1.html:
<applet code="MyApplet.class"
height="600"
width="800"
>
</applet>

10. To create thread by extending thread class
Coding:
class T1 extends Thread
{
public void run()
{
{
System.out.println("thread 1 created");
}
}
}
class T2 extends Thread
{
public void run()
{
{
}
}
}
class TMain
{
{
T1 obj1=new T1();
obj1.start();

T2 obj2=new T2();
obj2.start();
}
}

11. Create thread by implementing runnable interface
Coding:
class T1 implements Runnable
{
public void run()
{
{
}
}
}
class T2 implements Runnable
{
public void run()
{
{
}
}
}
class RMain
{
{
T1 obj1=new T1();
Thread t1=new Thread(obj1);
T2 obj2=new T2();
Thread t2=new Thread(obj2);
t1.start();
t2.start();

}
}

12. To create user defined exception
class InvalidRollno extends Exception

{

String msg;

public InvalidRollno()

{

}

public InvalidRollno(String m)

{

msg=m;

}

public String toString()

{

return(msg);

}

}

class Student

{

private int rollno;

public void setStudent(int r) throws InvalidRollno

{

rollno=r;

if(r<1)

{

throw new InvalidRollno("invalid rollno");

}

}

}

class SMain

{

public static void main(String agf[])

{

Student obj1=new Student();

try

{

obj1.setStudent(-11);

}

catch(InvalidRollno e)

{

System.out.println(e);

}

}

}

13. Program for showing the concept of sleep method in multithreading.

public class DelayExample{

public static void main(String[] args)

{

System.out.println("Hi");

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

{

System.out.println("Number of itartion = " + i);

System.out.println("Wait:");

try

{

Thread.sleep(4000);

}

catch (InterruptedException ie)

{

System.out.println(ie.getMessage());

}}}

14. Program to demonstrate a basic applet.

import java.awt.*;


/*

<applet code="sim" width=300 height=300>

</applet>

*/

public class sim extends Applet

{

String msg=" ";

public void init()

{

msg+="init()--->";

setBackground(Color.orange);

}

public void start()

{

msg+="start()--->";

setForeground(Color.blue);

}


{

msg+="paint()--->";

g.drawString(msg,200,50);

}}

15. Program for drawing various shapes on applets.

import java.awt.*;


/*

<applet code="Sujith" width=200 height=200>

</applet>

*/

public class Sujith extends Applet

{


{

for(int i=0;i<=250;i++)

{

Color c1=new Color(35-i,55-i,110-i);

g.setColor(c1);

g.drawRect(250+i,250+i,100+i,100+i);

g.drawOval(100+i,100+i,50+i,50+i);

g.drawLine(50+i,20+i,10+i,10+i);

}

}

}

16. Program for filling various objects with colours.

import java.awt.*;

public class GradientPaintExample extends ShapeExample {

private GradientPaint gradient =

new GradientPaint(0, 0, Color.red, 175, 175, Color.yellow,

true);

public void paintComponent(Graphics g)

{

clear(g)

Graphics2D g2d = (Graphics2D)g;

drawGradientCircle(g2d);

}

protected void drawGradientCircle(Graphics2D g2d)

g2d.setPaint(gradient);

g2d.fill(getCircle());

g2d.setPaint(Color.black);

g2d.draw(getCircle());

}

public static void main(String[] args) {

WindowUtilities.openInJFrame(new GradientPaintExample(),

380, 400);

}

17. Program of an applet which respond to mouse motion listener interface method.

import javax.swing.*;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.Graphics;

import java.awt.Container;

import java.awt.event.*;

public class MovingMessage

{

public static void main (String[] s)

{ HelloJava f = new HelloJava();}

}

class HelloJava extends JFrame implements MouseMotionListener, ActionListener

{

int messageX = 25, messageY = 100;

String theMessage;

JButton theButton;

int colorIndex = 0;

static Color[] someColors = { Color.black, Color.red,Color.green, Color.blue, Color.magenta };

HelloJava()

{

theMessage = "Dragging Message";

setSize(300, 200);

Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());

theButton = new JButton("Change Color");

contentPane.add(theButton);

theButton.addActionListener(this);

addMouseMotionListener(this);

setVisible(true);

}

private void changeColor()

{

if (++colorIndex == someColors.length)

colorIndex = 0;

setForeground(currentColor());

repaint();

}

private Color currentColor()

{ return someColors[colorIndex]; }


{

super.paint(g);

g.drawString(theMessage, messageX, messageY);

}

public void mouseDragged(MouseEvent e)

{

messageX = e.getX();

messageY = e.getY();

repaint();

}

public void mouseMoved(MouseEvent e) { }

public void actionPerformed(ActionEvent e)

{

if (e.getSource() == theButton)

changeColor();

}

}

18. Program of an applet which uses the various methods defined in the key listener
interface.

import java.awt.*;


public class KeyListenerTester extends Frame implements KeyListener{

TextField t1;

Label l1;

public KeyListenerTester(String s ) {

super(s);

Panel p =new Panel();

l1 = new Label ("Key Listener!" ) ;

p.add(l1);

add(p);

addKeyListener ( this ) ;

setSize ( 200,100 );

setVisible(true);

addWindowListener(new WindowAdapter(){

public void windowClosing(WindowEvent e){

System.exit(0);

}

});

}

public void keyTyped ( KeyEvent e ){

l1.setText("Key Typed");

}

public void keyPressed ( KeyEvent e){

l1.setText ( "Key Pressed" ) ;

}

public void keyReleased ( KeyEvent e ){

l1.setText( "Key Released" ) ;

}

public static void main (String[]args ){

new KeyListenerTester ( "Key Listener Tester" ) ;

}

}

19. program to change the background colour of applet by clicking on command button.

import java.applet.Applet;

import java.awt.Button;

import java.awt.Color;

public class ChangeButtonBackgroundExample extends Applet{

public void init()

{

Button button1 = new Button("Button 1");

Button button2 = new Button("Button 2");

button1.setBackground(Color.red);

button2.setBackground(Color.green);

add(button1);

add(button2);

}

}

20. Program of an applet that will demonstrate a basic calculator.

import java.awt.*;


import javax.swing.*;

import javax.swing.event.*;

class Calculator extends JFrame {

private final Font BIGGER_FONT = new Font("monspaced",

Font.PLAIN, 20);

private JTextField textfield;

private boolean number = true;

private String equalOp = "=";

private CalculatorOp op = new CalculatorOp();

public Calculator() {

textfield = new JTextField("0", 12);

textfield.setHorizontalAlignment(JTextField.RIGHT);

textfield.setFont(BIGGER_FONT);

ActionListener numberListener = new NumberListener();

String buttonOrder = "1234567890 ";

JPanel buttonPanel = new JPanel();

buttonPanel.setLayout(new GridLayout(4, 4, 4, 4));

for (int i = 0; i < buttonOrder.length(); i++) {

String key = buttonOrder.substring(i, i+1);

if (key.equals(" ")) {

buttonPanel.add(new JLabel(""));

} else {

JButton button = new JButton(key);

button.addActionListener(numberListener);

button.setFont(BIGGER_FONT);

buttonPanel.add(button);

}

}

ActionListener operatorListener = new OperatorListener();

JPanel panel = new JPanel();

panel.setLayout(new GridLayout(4, 4, 4, 4));

String[] opOrder = {"+", "-", "*", "/","=","C"};

for (int i = 0; i < opOrder.length; i++) {

JButton button = new JButton(opOrder[i]);

button.addActionListener(operatorListener);

button.setFont(BIGGER_FONT);

panel.add(button);

}

JPanel pan = new JPanel();

pan.setLayout(new BorderLayout(4, 4));

pan.add(textfield, BorderLayout.NORTH );

pan.add(buttonPanel , BorderLayout.CENTER);

pan.add(panel , BorderLayout.EAST );

this.setContentPane(pan);

this.pack();

this.setTitle("Calculator");

this.setResizable(false);

}

private void action() {

number = true;

textfield.setText("0");

equalOp = "=";

op.setTotal("0");

}

class OperatorListener implements ActionListener {

public void actionPerformed(ActionEvent e) {

if (number) {

action();

textfield.setText("0");

} else {

number = true;

String displayText = textfield.getText();

if (equalOp.equals("=")) {

op.setTotal(displayText);

} else if (equalOp.equals("+")) {

op.add(displayText);

} else if (equalOp.equals("-")) {

op.subtract(displayText);

} else if (equalOp.equals("*")) {

op.multiply(displayText);

} else if (equalOp.equals("/")) {

op.divide(displayText);

}

textfield.setText("" + op.getTotalString());

equalOp = e.getActionCommand();

}

}

}

class NumberListener implements ActionListener {

public void actionPerformed(ActionEvent event) {

String digit = event.getActionCommand();

if (number) {

textfield.setText(digit);

number = false;

} else {

textfield.setText(textfield.getText() + digit);

}

}

}

public class CalculatorOp {

private int total;

public CalculatorOp() {

total = 0;

}

public String getTotalString() {

return ""+total;

}

public void setTotal(String n) {

total = convertToNumber(n);

}

public void add(String n) {

total += convertToNumber(n);

}

public void subtract(String n) {

total -= convertToNumber(n);

}

public void multiply(String n) {

total *= convertToNumber(n);

}

public void divide(String n) {

total /= convertToNumber(n);

}

private int convertToNumber(String n) {

return Integer.parseInt(n);

}

}

}

21. Program for showing the use of various method of URL class.

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.MalformedURLException;

import java.net.URL;

public class GetURL {

static protected void getURL(String u) {

URL url;

InputStream is;

InputStreamReader isr;

BufferedReader r;

String str;

try {

System.out.println("Reading URL: " + u);

url = new URL(u);

is = url.openStream();

isr = new InputStreamReader(is);

r = new BufferedReader(isr);

do {

str = r.readLine();

if (str != null)

System.out.println(str);

} while (str != null);

} catch (MalformedURLException e) {

System.out.println("Must enter a valid URL");

} catch (IOException e) {

System.out.println("Can not connect");

}

}

static public void main(String args[]) {

if (args.length < 1)

System.out.println("Usage: GetURL ");

else

getURL(args[0]);

}

}

22. Program to print concentric circles

import java.awt.*;


import java.util.*;

public class c_cir extends Applet

{


{

Random rg = new Random();

for (int i=1; i<=3; i++)

{

int r = rg.nextInt(255);

int gr = rg.nextInt(255);

int b = rg.nextInt(255);

Color c = new Color(r,gr,b);

g.setColor(c);

g.fillOval(100+i*5,100+i*5,100-i*10,100-i*10);

}

}

}

23. Program to illustrate the use of methods of vector class

import java.util.*;
class vvect
{
public static void main(String a[])
{

Vector a1 = new Vector();

int l = a.length;
int i;
for(i=0;i<l;i++)
{
a1.addElement(a[i]);
}
a1.insertElementAt("Vatan",2);
int s = a1.size();
String r[] = new String[s];
a1.copyInto(r);
System.out.println("n Different Font Styles:n");
for(i=0;i<s;i++)
{
System.out.println(r[i]);
}
}
}

24. Program for showing the use ‘for’ in each statement.

package loops;

public class Forloops

{

public static void main(string[] args) {

int loopval;

int end_value=11;

for (loopval=0; loopval<end_value;loopval++) {

system.out.printin("loop value="+ loopval);

}

}

}

25. Program for showing a use of jdp programming in java.

import java.lang.*;
import java.sql.*;
class bca
{
public static void main(String arg[]) throws Exception
{
String stdrollno,stdname,stdclass;
Connection conn;

Statement stmt;
ResultSet rs;
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
conn=DriverManager.getConnection("jdbc:odbc:pctedsn","bca","bca");

stmt=conn.createStatement();
rs=stmt.executeQuery("select id,stdname,class from try");

System.out.println("Roll No Student Name Class");

while(rs.next())
{

stdclass = rs.getString(1);
stdname = rs.getString(2);
stdrollno = rs.getString(3);

System.out.println(stdrollno+" "+stdname+" "+stdclass);

}

//stmt.close();
//rs.close();
}
}

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