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Java practical


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Java practical

  1. 1. 1. Program to generate Fibonacci series import*; import java.util.*; public class Fibonacci { public static void main(String[] args) { DataInputStream reader = new DataInputStream((; 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
  2. 2. 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 javaCoding:class Person{String name[];int age[];}
  3. 3. class PersonMain{public static void main(String arg[]){Person obj=new Person(); String[6];obj.age=new int[6];[0]="Neha";obj.age[0]=19;[1]="manpreet";obj.age[1]=19;[2]="rahul";obj.age[2]=23;[3]="yuvraj";obj.age[3]=12;[4]="kombe";obj.age[4]=19;[5]="tony";obj.age[5]=19;
  4. 4. for(int i=0;i<4;i++)System.out.println([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 valuesCoding: import;class Customer{public static void main(String arf[]){DataInputStream myinput=new DataInputStream(;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());
  5. 5. 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);
  6. 6. } public double add(double a,double b) { double c=a+b; return (c); } } class AddMain { public static void main(String arg[]) { 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()
  7. 7. { 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(); Demo obj2=new Demo(); Demo obj3=new Demo(); } }7. To show concept of multilevel inheritance Coding: class A { private int num1,num2,sum; public void set(int x,int y) {
  8. 8. 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{public static void main(String args[]){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();}}
  9. 9. 8. To show concept of method overridingCoding: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{public static void main(String args[]){Demo obj1=new Demo();Demo obj2=new Demo();Demo obj3=new Demo();
  10. 10. 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: 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>
  11. 11. 10. To create thread by extending thread class Coding: class T1 extends Thread { public void run() { for(int i=0;i<5;i++) { System.out.println("thread 1 created"); } } } class T2 extends Thread { public void run() { for(int i=0;i<5;i++) { System.out.println("thread 2 created"); } } } class TMain { public static void main(String arg[]) { T1 obj1=new T1(); obj1.start(); T2 obj2=new T2(); obj2.start(); } }
  12. 12. 11. Create thread by implementing runnable interface Coding: class T1 implements Runnable { public void run() { for(int i=0;i<5;i++) { System.out.println("thread 1 created"); } } } class T2 implements Runnable { public void run() { for(int i=0;i<5;i++) { System.out.println("thread 2 created"); } } } class RMain { public static void main(String arg[]) { T1 obj1=new T1(); Thread t1=new Thread(obj1); T2 obj2=new T2(); Thread t2=new Thread(obj2); t1.start(); t2.start();
  13. 13. } }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); } }
  14. 14. 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);}
  15. 15. } }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 {
  16. 16. Thread.sleep(4000); }catch (InterruptedException ie) { System.out.println(ie.getMessage());}}}14. Program to demonstrate a basic applet.import java.awt.*;import java.applet.*;/*<applet code="sim" width=300 height=300></applet>*/public class sim extends Applet{String msg=" ";public void init()
  17. 17. {msg+="init()--->";setBackground(;}public void start(){msg+="start()--->";setForeground(;}public void paint(Graphics g){msg+="paint()--->";g.drawString(msg,200,50);}}15. Program for drawing various shapes on applets.import java.awt.*;import java.applet.*;/*
  18. 18. <applet code="Sujith" width=200 height=200></applet>*/public class Sujith extends Applet{public void paint(Graphics g){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);}}}
  19. 19. 16. Program for filling various objects with colours.import java.awt.*;public class GradientPaintExample extends ShapeExample {private GradientPaint gradient =new GradientPaint(0, 0,, 175, 175, Color.yellow,true);public void paintComponent(Graphics g){clear(g)Graphics2D g2d = (Graphics2D)g;drawGradientCircle(g2d);}protected void drawGradientCircle(Graphics2D g2d)
  20. 20. g2d.setPaint(gradient);g2d.fill(getCircle());g2d.setPaint(;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;
  21. 21. 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.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);
  22. 22. addMouseMotionListener(this);setVisible(true);}private void changeColor(){if (++colorIndex == someColors.length)colorIndex = 0;setForeground(currentColor());repaint();}private Color currentColor(){ return someColors[colorIndex]; }public void paint(Graphics g){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)
  23. 23. {if (e.getSource() == theButton)changeColor();}}18. Program of an applet which uses the various methods defined in the key listenerinterface.import java.awt.*;import java.awt.event.*;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 ) ;
  24. 24. 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" ) ;}}
  25. 25. 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(;button2.setBackground(;add(button1);add(button2);}}
  26. 26. 20. Program of an applet that will demonstrate a basic calculator.import java.awt.*;import java.awt.event.*;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);
  27. 27. 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);
  28. 28. }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();
  29. 29. 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);}
  30. 30. }}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);}
  31. 31. private int convertToNumber(String n) {return Integer.parseInt(n);}}}21. Program for showing the use of various method of URL class.import;import;import;import;import;import;public class GetURL {static protected void getURL(String u) {URL url;InputStream is;InputStreamReader isr;BufferedReader r;
  32. 32. 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 ");elsegetURL(args[0]);}}
  33. 33. 22. Program to print concentric circlesimport java.awt.*;import java.applet.*;import java.util.*;public class c_cir extends Applet{public void paint(Graphics g){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);
  34. 34. g.fillOval(100+i*5,100+i*5,100-i*10,100-i*10);}}}23. Program to illustrate the use of methods of vector classimport java.util.*;class vvect{ public static void main(String a[]) {
  35. 35. 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;
  36. 36. 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;
  37. 37. 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( { stdclass = rs.getString(1); stdname = rs.getString(2); stdrollno = rs.getString(3); System.out.println(stdrollno+" "+stdname+" "+stdclass); } //stmt.close(); //rs.close();}}