Java programming interview questions and answers
Program 1: Print Message.
class firstprogram
{
public static void main(String arg[])
{
System.out.println("this is java's first program");
}
}
Execution steps:
Javac firstprogram.java (File name)
Java firstprogram (class name)
Program 2: WAP to find the average,sum,min and max of the N numbers Using user
Input.
import java.util.*;
class Average{
public static void main(String args[])
{
Scanner sc= new Scanner(System.in);// to take user input
int choice;
int a=0,min=0,max=0,x;
int n =args.length;
System.out.println("1-sum");
System.out.println("2-Average");
System.out.println("3-Minimum");
System.out.println("4-Maximum");
System.out.println("Enter Ur Choice : ");
choice=sc.nextInt();
for(int i=0;i<n;i++){
a+=Integer.parseInt(args[i]);//to convert string into Integer
}
switch(choice)
{
case 1 :System.out.println("The sum is : "+a);
break;
case 2 :System.out.println("The Average is : "+a/n);
break;
case 3 :for(int i=0;i<n-1;i++)
{
x=Integer.parseInt(args[i]);
if(x<Integer.parseInt(args[i+1]))min=x;
else min=Integer.parseInt(args[i+1]);
}
System.out.println("The minimum is : "+min);
break;
case 4 :
for(int i=0;i<n-1;i++)
{
x=Integer.parseInt(args[i]);
if(x>Integer.parseInt(args[i+1]))
max=x;
else
max=Integer.parseInt(args[i+1]);
}
System.out.println("The maximum is : "+max);
break;
}
}
}
Program 3: WAP to Demonstrate Type Casting.
class typecast
{
public static void main(String args[])
{
byte h=127;
int a=300;
float a1=12.222f;
float g;
short b=200;
long c=999999;
float e=345.89F;
double f=45645.78222222222222;
g= (float)f;
System.out.println("short b ="+g);
System.out.println("short b ="+b);
System.out.println("long c ="+c);
System.out.println("float e="+e);
System.out.println("double f="+f);
System.out.println("short b="+b);
System.out.println("short to byte "+(byte)b);System.out.println("int to byte "+(byte)a);
System.out.println("int to float"+(float)a);
System.out.println("long to byte "+(byte)c);
System.out.println("double to long "+(long)f);
System.out.println("double to int "+(int)f);
System.out.println("double to byte "+(byte)f);
System.out.println("double to short "+(short)f);
System.out.println("double to float "+(float)f);
System.out.println("float to int "+(int)e);
System.out.println("float to byte "+(byte)e);
System.out.println("float to short "+(short)e);
System.out.println("float to long "+(long)e);
System.out.println("float to double ="+(double)e);
System.out.println("long to int"+(int)c);
System.out.println("byte to int ="+(int)h);
}
}
Program 4: WAP to Test the Prime num.
import java.util.*;
class prime
{
public static void main(String args[])
{
int flag,x,i;
flag=0;
int a[]=new int[7];
for(x=0;x<args.length;x++)
{
a[x]=Integer.parseInt(args[x]);
for(i=2;i<(a[x]/2);i++)
{
if((a[x]%i)==0)
{
break;
}
else flag=1;
}
if(flag==1)
System.out.println(a[x]+" is a prime no ");
else
System.out.println(a[x]+" is not a prime no ");
flag=0;
}}
}
Program 5: WAP to find out the HCF and LCF.
import java.util.*;
class hcf
{
public static void main(String args[])
{
int a,b;
Scanner sc= new Scanner(System.in);
System.out.println("Enter two nos :");
a=sc.nextInt();
b=sc.nextInt();
int big;
int small;
if(a>b)
{
big=a;
small=b;
}
else
{
big=b;
small=a;
}
for(int i=1;i<=big;i++)
{
if(((big*i)%small)==0)
{
int lcm=big*i;
System.out.println("The least common multiple is "+(lcm));
break;
}
}
int temp=1;
while(temp!=0)
{
temp=big%small;
if(temp==0)
{
System.out.println("GCD is "+small);
}
else
{
big=small;
small=temp;}}}}
Program 6: WAP to calculate the Simple Interest and Input by the user.
import java.util.*;
class si
{
int p,t;
float si,r;
public si()
{
r=0;
p=0;
}
public void getdata()
{
Scanner sc =new Scanner(System.in);
System.out.println("Enter principle : ");
p=sc.nextInt();
System.out.println("Enter rate : ");
r=sc.nextFloat();
System.out.println("Enter time period : ");
t=sc.nextInt();
}
public void cal()
{
si=(p*r*t)/100;
}
public void display()
{
System.out.println("Principle : Rs"+p);
System.out.println("Rate : "+r);
System.out.println("Time period : "+t);
System.out.println("Simple Interest : Rs"+si);
}
public static void main(String args[])
{
si s = new si();
s.getdata();
s.cal();
s.display();
}
}
Program 7:WAP to create a Simple class to find out the Area and perimeter of rectangle and box
using super and this keyword .
class rect
{
int l,b;
public rect(int l,int b)
{
this.l=l;
this.b=b;
}
public int area()
{
return l*b;
}
}
class box extends rect
{
int d;
public box(int l,int b,int d)
{
super(l,b);
this.d=d;
}
public int volume()
{
int vol = area()*d;
return vol;
}
public static void main(String args[])
{
int vol ,area;
System.out.println("derived object in derived reference");
rect r= new rect(10,20);
area=r.area();
System.out.println("area is "+area+"\n");
System.out.println("base object in base reference");
box b = new box(10,20,30);
vol=b.volume();
area=b.area();
System.out.println("area is "+area);
System.out.println("volume is "+vol+"\n");
System.out.println("derived object in base reference");
rect b1= new box(10,90,70);
area = b1.area();//vol=b1.volume(); as with refernce of base class we can't call derived's
method
System.out.println("area is "+area);
//as super class doesn't knw abt the base class but reference can be
assigned
/*System.out.println("base object in derived reference");
box b2=(new rect (10,20));
vol = b2.area();
System.out.println("area is "+area);*/
r=b;
System.out.println(r.area());
System.out.println(r.volume());
}
}
Program 8:WAP to design a class account using the inheritance and static that show all function
of bank(withrowal,deposite) and generate account number dyanamically.
import java.util.*;
class bank
{
static int acc_no =10001;
float amt;
public void display()
{
System.out.println("Account no :"+acc_no );
System.out.println("Current Amount :"+amt );
}
public bank()
{
amt=1000;
System.out.println("Ur account no is "+acc_no);
acc_no++;
}
public void getamt()
{
System.out.println("Current balance :"+amt);
}
public void withdraw(float x)
{
if(amt==1000 || amt<=x ){
System.out.println("Sorry u can't withdraw");
}
else
{
amt=amt-x;
System.out.println("amount withdrawn :"+x);
System.out.println("After withdrawl");
getamt();
}
}
public void deposit(float x)
{
if(x==0.0)
System.out.println("OOPS 0 can't be deposited");
else {
amt+=x;
System.out.println("After deposition");
getamt();}
}
public static void main(String args[])
{
Scanner sc = new Scanner(System.in);
bank b1 = new bank();
b1.deposit(0);
b1.withdraw(120.5f);
b1.display();
System.out.println("\n");
bank b2 = new bank();
b2.deposit(1000.0f);
b2.withdraw(150.5f);
}
}
Program 9: WAP to design a class Shape (Implement Runtime polymorphim) using
abstract Methods and Classes.
class AbstractDemo1
{
public static void main(String args[])
{Shape shape;
Rectangle r = new Rectangle();
r.setDimensions(40,20);
shape = r;
System.out.println(shape.getArea());
System.out.println(shape.getPerimeter());
}
}
abstract class Shape
{
void someMethod()
{
System.out.println("This is some method");
}
abstract float getArea();
abstract float getPerimeter();
}
class Square extends Shape
{
float side;
Square()
{
side = 0;
}
Square(float side)
{
this.side = side;
}
void setSide(float side)
{
this.side = side;
}
float getArea()
{
return side * side;
}
float getPerimeter()
{
return 4 * side;
}
}
import java.awt.*;class MyCircle extends MyShape
{
private float radius;
static float pi;
static
{
pi = 22 / 7.0f;
}
MyCircle()
{
super("circle");
radius = 0;
}
MyCircle(float radius)
{
super("circle");
this.radius = radius;
}
void setDimensions(float radius)
{
this.radius = radius;
}
void showDimensions()
{
System.out.println("radius : " + radius);
}
float getArea()
{
return radius * radius * pi;
}
}
class Rectangle extends Shape
{
private float length;
private float breadth;
Rectangle()
{
length = breadth = 0;
}Rectangle(float length, float breadth)
{
setDimensions(length, breadth);
}
void setDimensions(float length, float breadth)
{
this.length = length;
this.breadth = breadth;
}
float getArea()
{
return length * breadth;
}
float getPerimeter()
{
return (2 * (length + breadth));
}
}
Program 10:WAP to design a String class that perform String Method(Equal, Reverse
the string, change case, trim etc. )
public class StringDemo
{
public static void main(String args[])
{
String str = "This is some sample String with some words that have been
repeated some times";
System.out.println("Total no. of characters : " + str.length());
System.out.println("To Upper Case : " + str.toUpperCase());
System.out.println("To Lower Case : " + str.toLowerCase());
System.out.println("Original String : " + str);
System.out.println(str.substring(8));
System.out.println(str.substring(8,19));
System.out.println(str.indexOf("some"));
String s = "
" + str + " ";
System.out.println(s);
System.out.println("[" + s.trim() + "]");
System.out.println(str.replace("s","$$##"));String sh = "parth is a good boy";
System.out.println(sh + " -> " + new StringBuffer(sh).reverse());
}}
Program 11: WAP to handle the Exception using try and multiple catch block.
class exception
{
public static void main(String args[]){
try{
int d=42;
int a =0;
int c=d/a;
}
catch(ArithmeticException e){
System.out.println("Division by zero error");
}
}
}
Other Example:
public class ExceptionHandling
{
public static void main(String args[])
{
String num[]={"123","456","abc","789"};
int sum=0;
int i;
for(i=0;i<=num.length;i++)
{
try{
sum+=Integer.parseInt(num[i]);
}
catch(NumberFormatException e)
{ System.out.println("NUMBER FORMAT ERROR");
}
catch(ArrayIndexOutOfBoundsException e)
{System.out.println("ARRAY ERROR");
}
finally
{ System.out.println("i = "+i);
}
}System.out.println("sum is"+sum);
}
}
Program 12:WAP that Implement the Nested try Statements.
class NestedTry
{
public static void main(String args[])
{
int a=args.length;
try{
int d=42/a;
try
{
if(a==1){
int c= a/(a-a);}
if(a==2)
{
int c[]={2,3,4};
c[5]=90;
}
}
catch(ArrayIndexOutOfBoundsException e)
{e.printStackTrace();
}
}
catch(ArithmeticException e)
{
e.printStackTrace();
}
}
}
Program 13:WAP that Implement Throw and Throws.
class ThrowDemo
{
ThrowDemo()
{
try
{ throw new NullPointerException();
}
catch(NullPointerException e)
{System.out.println("Caught in constructor");
throw e;
}
}
public static void main(String args[])
{
try{
ThrowDemo td=new ThrowDemo();
}
catch(NullPointerException e)
{
System.out.println("Caught in Main");
}
}
}
class ThrowsDemo
{
ThrowsDemo() throws NullPointerException
{ System.out.print("in constructor");
throw new NullPointerException();
}
public static void main(String args[])
{
try{
ThrowsDemo td=new ThrowsDemo();
}
catch(NullPointerException e)
{
System.out.println("Caught in Main");
}
}
}
Program 14: WAP that Implement Custom Exception.
import java.util.*;
class MyException extends Exception
{
private int e;
MyException (int a )
{
e=a;}
public String toString()
{
return ("Error in entry"+e);
}
}
public class mine
{
public void compute(int a) throws MyException
{
int age=a;
if(age>150)
throw new MyException (age);
System.out.println("COrrect age");
}
public static void main(String args[])
{
mine m=new mine();
try{
m.compute(1);
m.compute(789);
}
catch(MyException e)
{
System.out.println(e);
}
}
}
Program 15: WAP to Create a package that access the member of external class as well
as same package.
package pack;
class base
{
public static void main(String arg[])
{
System.out.println("Base class(p1)");
p1 w=new p1();
//w.f1();
System.out.println("Derived class(p2)");
p2 x=new p2();
//
x.f2();
System.out.println("Simple class(p3)");
p3 y=new p3();//
}
y.f3();
}
package pack;
public class p1
{
int a=1;
public int b=2;
private int c=3;
protected int d=4;
public p1()
{
System.out.println("Value of a="+a);
System.out.println("Value of b="+b);
System.out.println("Value of c="+c);
System.out.println("Value of d="+d);
}
}
package pack;
class p2 extends p1
{
p2()
{
System.out.println("Value of a="+a);
System.out.println("Value of b="+b);
//System.out.println("Value of c="+c);
System.out.println("Value of d="+d);
}
}
package pack;
class p3
{
p1 p=new p1();
p3()
{
System.out.println("Value of a="+(p.a));
System.out.println("Value of b="+(p.b));
//System.out.println("Value of c="+(p.c));
System.out.println("Value of d="+(p.d));
}
}package pack1;
class simple extends pack.p1
{
public simple()
{
//
//
System.out.println("Value of a="+a);
System.out.println("Value of b="+b);
System.out.println("Value of c="+c);
System.out.println("Value of d="+d);
}
}
package pack1;
class s2
{
public static void main(String arg[])
{
simple s=new simple();
s1 p=new s1();
}
}
package pack1;
class s1
{
s1()
{
pack.p1 z=new pack.p1();
//
System.out.println("Value of a="+(z.a));
System.out.println("Value of b="+(z.b));
//
System.out.println("Value of c="+(z.c));
//
System.out.println("Value of d="+(z.d));
}
}
Program16: WAP that show the partial implementation of Interface.(calculation of
Salary of Employee).
import java.util.*;
interface salary
{
int getsal();
}abstract class employee
{
String name;
int age;
String sex;
int sal;
employee(String name,int age,String sex,int sal)
{
this.name=name;
this.age=age;
this.sex=sex;
this.sal=sal;
}
abstract void display();
}
class labour extends employee implements salary
{
int wage;
int hrs;
labour(String name,int age,String sex,int sal,int hrs)
{
super(name,age,sex, sal);
this.hrs=hrs;
}
public int getsal()
{
wage=sal*hrs;
return wage;
}
void display()
{
System.out.println("name :"+name);
System.out.println("Age :"+age);
System.out.println("Sex :"+sex);
System.out.println("salary : Rs"+sal);
System.out.println("Hours worked :"+hrs);
System.out.println("Wage of the daily labour :Rs"+getsal());
}
}
class staff extends employee implements salary
{
int hra,da,ta;
staff(String name,int age,String sex,int sal,
int hra,int da,int ta)
{
super(name,age,sex, sal);
this.da=da;
this.ta=ta;this.hra=hra;
}
public int getsal()
{
int wage=sal+ta+da+hra;
return wage;
}
void display()
{
System.out.println("name :"+name);
System.out.println("Age :"+age);
System.out.println("Sex :"+sex);
System.out.println(" basic salary :Rs"+sal);
System.out.println("Daily allowance : Rs"+da);
System.out.println("Travel allowance : Rs"+ta);
System.out.println("Household allowance : Rs"+hra);
System.out.println("total salary :Rs"+getsal());
}
}
class sal
{
public static void main(String args[])
{
Scanner sc= new Scanner (System.in);
int ch,da,ta,hra,sal,hrs,age;
String name;
String sex;
System.out.println("Enter ur choice for salary calculation");
System.out.println("1-labour");
System.out.println("2-Staff");
ch=sc.nextInt();
switch(ch)
{
case 1 :
System.out.println("Enter the following for a lobour");
System.out.print("Name :");
name=sc.next();
System.out.println("age :");
age=sc.nextInt();
System.out.println("Sex : ");
sex=sc.next();
System.out.println("salary :");
sal=sc.nextInt();
System.out.println("daily working hours :");
hrs=sc.nextInt();
labour l = new labour(name,age,sex,sal,hrs);l.display();
break;
case 2 :
System.out.println("Enter the following for a Staff");
System.out.println("Name :");
name=sc.next();
System.out.println("age :");
age=sc.nextInt();
System.out.println("Sex : ");
sex=sc.next();
System.out.println("salary : ");
sal=sc.nextInt();
System.out.println("daily allowance :");
da=sc.nextInt();
System.out.println("travel allowance :");
ta=sc.nextInt();
System.out.println("household allowance :");
hra=sc.nextInt();
staff s = new staff(name,age,sex,sal,hra,da,ta);
s.display();
break;
}
}
Program 17:WAP to create Arithmetic Math Calculator Using Applet Class ant Event Handling.
/*<APPLET CODE ="calc.class" WIDTH =300 HEIGHT =400>
</APPLET>*/
import java.awt.event.*;
import java.awt.*;
import java.applet.Applet;
public class calc extends Applet implements ActionListener
{
Button add,sub,divide,multi;
Label result,no1,no2;
TextField tf,ip1,ip2;
Panel p1,p2,p3;
public void init()
{
add=new Button("ADD");
sub=new Button("SUBTRACT");
divide=new Button("DIVIDE");
multi=new Button("MULTIPLY");result = new Label("Result = ");
no1=new Label ("NUMBER 1:");
no2=new Label ("NUMBER 2:");
tf=new TextField(20);
ip1=new TextField(10);
ip2=new TextField(10);
p1=new Panel();
p2=new Panel();
p3=new Panel();
tf.setEditable(false);
add.setSize(20,40);
sub.setSize(20,40);
divide.setSize(20,40);
add.addActionListener(this);
sub.addActionListener(this);
divide.addActionListener(this);
multi.addActionListener(this);
setLayout(new FlowLayout());
p1.add(no1);
p1.add(ip1);
p1.add(no2);
p1.add(ip2);
p2.add(add);
p2.add(sub);
p2.add(divide);
p2.add(multi);
p3.add(result);
p3.add(tf);
add(p1);
add(p2);
add(p3);
setSize(400,200);
setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
int a,b;
int result;
a =Integer.parseInt(ip1.getText());
b=Integer.parseInt(ip2.getText());
if(e.getSource()==add){System.out.println("ADD");
result=(a+b);
tf.setText("Addition :"+String.valueOf(result));
}
if(e.getSource()==sub)
{
result=(a-b);
tf.setText("Subtraction : "+String.valueOf(result));
}
if(e.getSource()==multi)
{
result=(a*b);
tf.setText("Multiplication : "+String.valueOf(result));
}
if(e.getSource()==divide)
{
try{
if(b==0)
{
result=(a/b);
tf.setText("Division :"+String.valueOf(result));
}
}
catch(ArithmeticException ae )
{
tf.setText("Division can't be performed");
}
}
}
}
Program 18: WAP to Draw the line, Rectangle, oval, text etc using the graphics method.
/*<applet code = "AppletDemo.class" width = "500"
</applet>*/
import java.applet.Applet;
import java.awt.*;
public class AppletDemo extends Applet
{
public void init()
{setBackground(Color.cyan);
}
public void paint(Graphics g)
{
height = "300">Font f=new Font("TIMES NEW ROMAN ",Font.ITALIC,32);
g.setFont(f);
g.setColor(Color.orange);
g.drawString("WELCOME TO APPLET ",30,30);
g.fillOval(60,60,150,150);
g.setColor(Color.black);
g.fillOval(90,100,20,20);
g.fillOval(160,100,20,20);
g.setColor(Color.RED);
g.drawLine(120,150,150,150);
g.drawLine(120,150,140,130);
g.drawArc(90,130,90,60,0,-180);
}
}
Program 19: WAP to create a frame Window Using Frame Class.
public class AWT1
{
public static void main(String args[])
{
MyFrame mf = new MyFrame();
}
}
import java.awt.event.*;
/*
class MyWindowListener implements WindowListener
{
public void windowActivated(WindowEvent we){}
public void windowDeactivated(WindowEvent we){}
public void windowOpened(WindowEvent we){}
public void windowClosed(WindowEvent we){}
public void windowIconified(WindowEvent we){}
public void windowDeiconified(WindowEvent we){}
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
}
*/class MyWindowAdapter extends WindowAdapter
{
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
}
import java.awt.*;
import java.awt.event.*;
class MyFrame extends Frame //implements WindowListener
{
MyFrame()
{
super("Sample Java Frame");
//MyWindowListener mwl = new MyWindowListener();
//MyWindowAdapter mwa = new MyWindowAdapter();
//addWindowListener(mwa);
addWindowListener(new MyWindowAdapter());
//addWindowListener(this);
setSize(400,300);
setResizable(true);
//setUndecorated(true);
setVisible(true);
}
}
Program 20: WAP to create UI component on Frame Window Using Frame Class.
public class AWT1
{
public static void main(String args[])
{
MyFrame mf = new MyFrame();
}
}import java.awt.event.*;
class MyWindowAdapter extends WindowAdapter
{
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
}
import java.awt.*;
import java.awt.event.*;
class MyFrame extends Frame
{
Label lbl, l2;
TextField t1;
MyFrame()
{
super("Sample Java Frame");
addWindowListener(new MyWindowListener());
setSize(500,400);
addControls();
setVisible(true);
}
private void addControls()
{
setLayout(null);
lbl = new Label("Sample Label",Label.CENTER);
lbl.setSize(250,22);
lbl.setLocation(10,40);
//lbl.setText("This is the text in the label control");
lbl.setBackground(Color.YELLOW);
lbl.setForeground(Color.RED);//lbl.setAlignment(Label.RIGHT);
add(lbl);
l2 = new Label(lbl.getText());
l2.setSize(lbl.getSize());
l2.setLocation(lbl.getLocation().x, lbl.getLocation().y + 30);
l2.setAlignment(lbl.getAlignment());
l2.setBackground(lbl.getForeground());
l2.setForeground(lbl.getBackground());
//l2.setVisible(false);
add(l2);
t1 = new TextField("This is some initial text in the text box control");
t1.setSize(200,22);
t1.setLocation(10,160);
t1.setEchoChar('^');
if (t1.echoCharIsSet())
{
System.out.println("Input has been masked");
System.out.println("Mask character is " + t1.getEchoChar());
}
add(t1);
//
}
t1.setEnabled(false);
t1.setEditable(false);
}
Program 21: WAP to implement ListBox.
public class AWT1
{
public static void main(String args[])
{
MyFrame mf = new MyFrame();
}
}
import java.awt.*;
import java.awt.event.*;
public class MyFrame extends Frame implements ActionListener
{
List lst;
Button btn;
MyFrame(){
super("Sample Java Frame");
addWindowListener(new MyWindowAdapter());
setSize(500,400);
addControls();
setVisible(true);
}
private void addControls()
{
setLayout(null);
lst = new List();
lst.setLocation(30,50);
lst.setSize(200,300);
lst.setMultipleMode(true);
add(lst);
lst.add("sfsdf");
lst.add("55656");
lst.add("dfgdfg");
lst.add("sfsdf");
lst.add("cvb");
lst.add("sfcvbcbcvbcvbsdf");
lst.add("bmmbnm");
lst.add("ioouo");
lst.add("qeqwe");
lst.add(".m,.m,.");
btn = new Button("Click Me");
btn.addActionListener(this);
btn.setSize(100,24);
btn.setLocation(250,50);
add(btn);
}
public void actionPerformed(ActionEvent ae)
{
System.out.println("Total Selected Items : " +
lst.getSelectedItems().length);
String aItem[] = lst.getSelectedItems();
int i;
for (i=0;i<aItem.length;i++)System.out.println(aItem[i]);
}
}
import java.awt.event.*;
class MyWindowAdapter extends WindowAdapter
{
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
}
Program 22: WAP to implement Choice, Checkbox, radio button With event handling.
public class AWT1
{
public static void main(String args[])
{
MyFrame mf = new MyFrame();
}
}
import java.awt.*;
import java.awt.event.*;
class MyFrame extends Frame implements ItemListener
{
Checkbox c1, c2, c3, c4, c5, c6;
CheckboxGroup cbg1, cbg2;
Choice cbo;
MyFrame()
{
super("Sample Java Frame");
addWindowListener(new MyWindowAdapter());
setSize(500,400);
addControls();
setVisible(true);
}
private void addControls()
{setLayout(new FlowLayout());
cbg1 = new CheckboxGroup();
cbg2 = new CheckboxGroup();
c1 = new Checkbox("C", true);
c2 = new Checkbox("C++",cbg2,true);
c3 = new Checkbox("Java",cbg2, true);
c4 = new Checkbox("Prolog", cbg1,false);
c5 = new Checkbox("Lisp", true, cbg1);
c6 = new Checkbox("Fortran");
c1.addItemListener(this);
c2.addItemListener(this);
c3.addItemListener(this);
c4.addItemListener(this);
c5.addItemListener(this);
c6.addItemListener(this);
//c2.setState(true);
//c5.setState(false);
add(c1);
add(c2);
add(c3);
add(c4);
add(c5);
add(c6);
cbo = new Choice();
cbo.add("Delhi");
cbo.add("Ajmer");
cbo.add("Jaipur");
cbo.add("Mumbai");
cbo.insert("Beawar",0);
cbo.add("Chandigarh");
cbo.add("Jalandhar");
cbo.add("Nasirabad");
cbo.add("Bharatpur");
cbo.select(3);
cbo.addItemListener(this);
add(cbo);}
public void itemStateChanged(ItemEvent ie)
{
if (ie.getSource() instanceof Checkbox)
{
Checkbox c = (Checkbox) ie.getSource();
System.out.println(c.getLabel() + " : " + c.getState());
}
else if (ie.getSource() instanceof Choice)
{
System.out.println("Selected Index : " + cbo.getSelectedIndex());
System.out.println("Selected Item : " + cbo.getSelectedItem());
}
}
}
import java.awt.event.*;
class MyWindowAdapter extends WindowAdapter
{
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
}
Program 23: WAP to implement Layout Manager.
public class AWT1
{
public static void main(String args[])
{
MyFrame mf = new MyFrame();
}
}
import java.awt.*;
import java.awt.event.*;
class MyFrame extends Frame implements ActionListener
{
Panel mainPanel, p1, p2, p3, p4, p5, topPanel;
CardLayout cl;
TextField txt[];
Button btn[], b1, b2, b3, b4, b5;TextArea ta[];
Label lbl[];
Choice choice[];
MyFrame()
{
super("Sample Java Frame");
addWindowListener(new MyWindowAdapter());
setSize(400,300);
addControls();
setVisible(true);
}
private void addControls()
{
cl = new CardLayout();
mainPanel = new Panel();
mainPanel.setLayout(cl);
int i;
GridLayout gl = new GridLayout(5,10,5,5);
p1 = new Panel();
p1.setLayout(gl);
txt = new TextField[50];
for (i=0;i<txt.length;i++)
{
txt[i] = new TextField("Text " + (i+1));
p1.add(txt[i]);
}
p2 = new Panel();
p2.setLayout(gl);
btn = new Button[50];
for (i=0;i<btn.length;i++)
{
btn[i] = new Button("Button " + (i+1));
btn[i].addActionListener(this);
p2.add(btn[i]);
}
p3 = new Panel();
p3.setLayout(gl);
ta = new TextArea[50];
for (i=0;i<ta.length;i++)
{
ta[i] = new TextArea("Text " + (i+3));p3.add(ta[i]);
}
p4 = new Panel();
p4.setLayout(gl);
lbl = new Label[50];
for (i=0;i<lbl.length;i++)
{
lbl[i] = new Label("Label " + (i+4));
p4.add(lbl[i]);
}
p5 = new Panel();
p5.setLayout(gl);
choice = new Choice[50];
for (i=0;i<choice.length;i++)
{
choice[i] = new Choice();
p5.add(choice[i]);
}
mainPanel.add(p1,"panel1");
mainPanel.add(p2,"panel2");
mainPanel.add(p3,"panel3");
mainPanel.add(p4,"panel4");
mainPanel.add(p5,"panel5");
add(mainPanel);
b1 = new Button("Card 1");
b2 = new Button("Card 2");
b3 = new Button("Card 3");
b4 = new Button("Card 4");
b5 = new Button("Card 5");
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
b4.addActionListener(this);
b5.addActionListener(this);
topPanel = new Panel();
topPanel.setLayout(new FlowLayout());
topPanel.add(b1);
topPanel.add(b2);topPanel.add(b3);
topPanel.add(b4);
topPanel.add(b5);
add(topPanel, BorderLayout.NORTH);
}
public void actionPerformed(ActionEvent ae)
{
if (ae.getSource() == b1)
cl.show(mainPanel,"panel1");
else if (ae.getSource() == b2)
cl.show(mainPanel,"panel2");
else if (ae.getSource() == b3)
cl.show(mainPanel,"panel3");
else if (ae.getSource() == b4)
cl.show(mainPanel,"panel4");
else if (ae.getSource() == b5)
cl.show(mainPanel,"panel5");
else
{
int i;
boolean found = false;
for (i=0;i<btn.length;i++)
{
if (ae.getSource() == btn[i])
{
found = true;
break;
}
}
if (found)
{
System.out.println("Button Clicked from panel : " +
btn[i].getLabel());
}
}
}
}
import java.awt.event.*;
class MyWindowAdapter extends WindowAdapter
{
public void windowClosing(WindowEvent we)
{System.exit(0);
}
}
Program 24: WAP to implement Dialog box.
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
/*
<applet code="DialogDemo" width =250 height = 250>
</applet>
*/
class SampleDialog extends Dialog implements ActionListener
{
SampleDialog(Frame parent,String title)
{
super(parent,title,false);
setLayout(new FlowLayout());
setSize(300,200);
add(new Label("Press this button: "));
Button b;
add(b= new Button("Cancel"));
b.addActionListener(this);
}
public void actionPerformed(ActionEvent ae)
{
dispose();
}
public void paint(Graphics g)
{
g.drawString("This is in the dialog box",10,70);
}
}
class MenuFrame extends Frame
{
String msg = "";
CheckboxMenuItem debug,test;
MenuFrame(String title)
{
super(title);
MenuBar mbar = new MenuBar();setMenuBar(mbar);
//Menu Bar added on applet
Menu file = new Menu("File");
MenuItem item1,item2,item3,item4,item5;
file.add(item1=new MenuItem("New..."));
file.add(item2=new MenuItem("Open..."));
file.add(item3=new MenuItem("Close"));
file.add(item4=new MenuItem("-"));
file.add(item5=new MenuItem("Quit..."));
mbar.add(file);//Menu File is created
//Menu items for File created
//Menu Items added in Menu
Menu edit = new Menu("Edit");
MenuItem item6,item7,item8,item9;
edit.add(item6=new MenuItem("Cut"));
edit.add(item7=new MenuItem("Copy"));
edit.add(item8=new MenuItem("Paste"));
edit.add(item9=new MenuItem("-"));//Menu Edit is created
//Menu items for Edit created
//Menu Items added in Menu
// Menu File added on Menu
Bar
Menu sub = new Menu("Special",true);
//Menu Special is
created
MenuItem item10,item11,item12;
//Menu items for Special
created
sub.add(item10=new MenuItem("First"));
//Menu Items added in Menu
sub.add(item11=new MenuItem("Second"));
sub.add(item12=new MenuItem("Third"));
edit.add(sub);
//Menu Special added in Edit Menu
debug = new CheckboxMenuItem("Debug");
edit.add(debug);
test = new CheckboxMenuItem("Testing");
edit.add(test);
mbar.add(edit);
//Menu Edit added on Menu
Bar
MyMenuHandler handler = new MyMenuHandler(this);//added a handler for
menu
item1.addActionListener(handler);
item
item2.addActionListener(handler);
item3.addActionListener(handler);
item4.addActionListener(handler);
item5.addActionListener(handler);
//added an Action Listener for eachitem6.addActionListener(handler);
item7.addActionListener(handler);
item8.addActionListener(handler);
item9.addActionListener(handler);
item10.addActionListener(handler);
item11.addActionListener(handler);
item12.addActionListener(handler);
debug.addItemListener(handler);
test.addItemListener(handler);
MyWindowAdapter adapter = new MyWindowAdapter(this);
addWindowListener(adapter);
}
public void paint(Graphics g)
{
g.drawString(msg,10,200);
if(debug.getState())
g.drawString("Debug is on...",10,220);
else
g.drawString("Debug is off...",10,220);
if(test.getState())
g.drawString("Testing is on...",10,240);
else
g.drawString("Testing is off...",10,240);
}
}
class MyWindowAdapter extends WindowAdapter
{
MenuFrame menuFrame;
public MyWindowAdapter(MenuFrame menuFrame)
{
this.menuFrame=menuFrame;
}
public void WindowClosing(WindowEvent we)
{
menuFrame.dispose();
}
}
class MyMenuHandler implements ActionListener,ItemListener
{
MenuFrame menuFrame;
public MyMenuHandler(MenuFrame menuFrame){
this.menuFrame=menuFrame;
}
public void actionPerformed(ActionEvent ae)
{
String msg="You selected";
String arg=(String)ae.getActionCommand();
if(arg.equals("New..."))
{
msg+=" New.";
SampleDialog d= new SampleDialog(menuFrame,"New Dialog Box");
d.setVisible(true);
}
else if(arg.equals("Open..."))
msg+=" Open.";
else if(arg.equals("Close"))
msg+=" Close.";
else if(arg.equals("Quit..."))
msg+=" Quit.";
else if(arg.equals("Edit"))
msg+=" Edit.";
else if(arg.equals("Cut"))
msg+=" Cut.";
else if(arg.equals("Copy"))
msg+=" Copy.";
else if(arg.equals("Paste"))
msg+=" Paste.";
else if(arg.equals("First"))
msg+=" First.";
else if(arg.equals("Second"))
msg+=" Second.";
else if(arg.equals("Third"))
msg+=" Third.";
else if(arg.equals("Debug"))
msg+=" Debug.";
else if(arg.equals("Testing"))
msg+=" Testing.";
menuFrame.msg=msg;
menuFrame.repaint();
}
public void itemStateChanged(ItemEvent ie)
{
menuFrame.repaint();
}
}public class DialogDemo extends Applet
{
Frame f;
public void init()
{
f=new MenuFrame("Menu Demo");
int width=Integer.parseInt(getParameter("width"));
int height=Integer.parseInt(getParameter("height"));
setSize(new Dimension(width,height));
f.setSize(width,height);
f.setVisible(true);
}
public void start()
{
f.setVisible(true);
}
public void stop()
{
f.setVisible(false);
}
}
Program 25: WAP to implement Smiley face Using applet.
import java.awt.*;
import java.applet.*;
/*<APPLET
CODE = Face.class
WIDTH =250
HEIGHT = 200 >
<param name="a" value =10>
<param name="b" value =20>
</APPLET>*/
public class Face extends Applet
{
public void paint (Graphics g)
{
String a;
String b;
String c;
a=getParameter("a");
b=getParameter("b");
int p=Integer.parseInt(a);int q=Integer.parseInt(b);
int sum=p+q;
c=Integer.toString(sum);
g.drawString("First value :-"+a,10,210);
g.drawString("Second value :-"+b,10,230);
g.drawString("Total sum :-"+c,10,250);
g.drawLine(10,212,130,212);
g.drawLine(10,232,130,232);
g.drawLine(10,252,130,252);
Color c1=new Color(25,0,0);
setBackground(c1);
setForeground(Color.green);
g.drawRect(200,160,100,50);
g.fillRect(200,40,100,50);
g.drawOval(40,40,120,150);
g.drawOval(57,75,30,20);
g.drawOval(110,75,30,20);
g.fillOval(68,81,10,10);
g.fillOval(121,81,10,10);
g.drawOval(85,100,30,30);
g.fillArc(60,125,80,40,180,180);
g.drawOval(25,92,15,30);
g.drawOval(160,92,15,30);
}
}
Program 26: WAP to create Frame that display the student information.
import java.awt.*;
import java.awt.event.*;
public class Studentinfo
{static StudFrame sf;
public static void main(String args[])
{
sf = new StudFrame();
}
}
class mywindowadapter extends WindowAdapter
{
//
StudFrame sf;
//
public mywindowadapter(StudFrame sf)
//
{
//
this.sf=sf;
//
}
//
public void windowClosing(WindowEvent we)
{
//
sf.setVisible(false);
System.exit(0);
}
}
class StudFrame extends Frame implements ActionListener,ItemListener
{
Button b1,b2,b3,b4;
static TextField t1,t2;
static Choice c,c1,c2,cc;
static Label lh,l1,l2,l3,l4,l5,l6;
//static List lb;
static Checkbox cb1,cb2;
static CheckboxGroup gndr=new CheckboxGroup();
StudFrame()
{
super("Student Records Form");
//mywindowadapter mw=new mywindowadapter(this);
addWindowListener(new mywindowadapter());
addcontrols();
setSize(700,550);
setResizable(true);
setVisible(true);
}
void addcontrols(){
setLayout(null);
lh=new Label("Student Records");
l1=new Label("Student ID");
l2=new Label();
l2.setText("Name");
l3=new Label("Gender");
l4=new Label("Age");
l5=new Label("Qualification");
l6=new Label("Course");
t1=new TextField(8);
t2=new TextField(8);
cb1=new Checkbox("Male",gndr,true);
cb2=new Checkbox("Female",gndr,false);
cc=new Choice();
for(int i=15;i<=80;i++)
cc.add(Integer.toString(i));
c=new Choice();
c.add("Under Graduate");
c.add("Graduate");
c1=new Choice();
c1.add("B.A.");
c1.add("B.B.A.");
c1.add("B.C.A.");
c1.add("B.Com");
c1.add("B.E./B.Tech");
c1.add("B.Pharma");
c1.add("B.Sc.");
c2=new Choice();
c2.add("M.B.A.");
c2.add("M.C.A.");
c2.add("M.E./M.Tech");
b1=new Button("OK");
b2=new Button("Cancel");b3=new Button("Reset");
b4=new Button("Exit");
lh.setBounds(100,30,100,30);
l1.setBounds(100,60,100,30);
l2.setBounds(100,90,100,30);
l3.setBounds(100,120,100,30);
l4.setBounds(100,150,100,30);
l5.setBounds(100,180,100,30);
l6.setBounds(100,210,100,30);
t1.setBounds(250,60,150,20);
t2.setBounds(250,90,150,20);
cb1.setBounds(250,120,40,20);
cc.setBounds(250,150,150,20);
c.setBounds(250,180,150,20);
c1.setBounds(250,210,150,20);
c2.setBounds(250,210,150,20);
b1.setBounds(500,90,100,35);
b3.setBounds(125,290,100,35);
add(lh);
add(l1);
add(l2);
add(l3);
add(l4);
add(l5);
add(l6);
add(t1);
add(t2);
add(cb1);
add(cb2);
add(cc);
add(c);
add(c1);
c1.setVisible(true);
add(c2);
c2.setVisible(false);
add(b1);
add(b2);
add(b3);
add(b4);
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
b4.addActionListener(this);
cb2.setBounds(310,120,60,20);
b2.setBounds(500,180,100,35);
b4.setBounds(300,290,100,35);c.addItemListener(this);
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource()==b1)
{
subframe s=new subframe("Submission","Data entered successfully.");
String s1=t1.getText();
String s2=t2.getText();
if(s1.length()==0 || s1.length()==0 )
{
s.setSize(300,100);
}
else
{
s.setSize(350,350);
}
s.setVisible(true);
StudentInfo.sf.setEnabled(false);
}
else if(ae.getSource()==b2)
{
subframe s=new subframe("Cancellation","Data is not
accepted(Cancellation done).");
s.setSize(300,100);
s.setVisible(true);
StudentInfo.sf.setEnabled(false);
}
else if(ae.getSource()==b3)
{
t1.setText("");
t2.setText("");
gndr.setSelectedCheckbox(cb1);
c.select(0);
cc.select(0);
c1.select(0);
c1.setVisible(true);
}
else if(ae.getSource()==b4)
{
System.exit(0);
}
}public void itemStateChanged(ItemEvent ie)
{
String s = c.getSelectedItem();
if(s=="Under Graduate")
{
c1.setVisible(true);
c2.setVisible(false);
}
if(s=="Graduate")
{
c1.setVisible(false);
c2.setVisible(true);
}
}
}
class subwindowadapter extends WindowAdapter
{
subframe subf;
public subwindowadapter(subframe subf)
{
this.subf=subf;
}
public void windowClosing(WindowEvent we)
{
StudentInfo.sf.setEnabled(true);
subf.setVisible(false);
}
}
class subframe extends Frame implements ActionListener
{
Button bsubok=new Button("OK");
subframe()
{}
subframe(String title) {}
subframe(String title,String msg)
{
super(title);
String s1=StudFrame.t1.getText();
String s2=StudFrame.t2.getText();subwindowadapter sw=new subwindowadapter(this);
addWindowListener(sw);
if(title=="Cancellation")
{
//
StudFrame.t1.setText("");
//
StudFrame.t2.setText("");
setLayout(new FlowLayout(FlowLayout.CENTER));
add(new Label(msg));
add(bsubok);
bsubok.addActionListener(this);
}
else
{
if(s1.length()==0)
{
//resize(300,100);
setLayout(new FlowLayout(FlowLayout.CENTER));
add(new Label("Please fill in Student Name."));
add(bsubok);
bsubok.addActionListener(this);
}
else if(s2.length()==0)
{
setLayout(new FlowLayout(FlowLayout.CENTER));
add(new Label("Please fill in Student Roll Number."));
add(bsubok);
bsubok.addActionListener(this);
}
else
//add(new Label(StudFrame.t1.getText() +", Student ID:
"+StudFrame.t2.getText()+" Accepted.",Label.CENTER));
{
setLayout(null);
Label lhl,ll1,ll2,ll3,ll4,ll5,ll6,la1,la2,la3,la4,la5,la6,ltl;
lhl=new Label("Your data is:");
ll1=new Label("Student ID");
ll2=new Label();
ll2.setText("Name");
ll3=new Label("Gender");
ll4=new Label("Age");
ll5=new Label("Qualification");
ll6=new Label("Course");ltl=new Label(msg);
la1=new Label(StudFrame.t1.getText());
la2=new Label();
la2.setText(StudFrame.t2.getText());
la3=new
Label(StudFrame.gndr.getSelectedCheckbox().getLabel());
la4=new Label(StudFrame.cc.getSelectedItem());
la5=new Label(StudFrame.c.getSelectedItem());
if(StudFrame.c.getSelectedItem()=="Under Graduate")
la6=new Label(StudFrame.c1.getSelectedItem());
else
la6=new Label(StudFrame.c2.getSelectedItem());
add(lhl);
add(ll1);
add(ll2);
add(ll3);
add(ll4);
add(ll5);
add(ll6);
add(la1);
add(la2);
add(la3);
add(la4);
add(la5);
add(la6);
add(ltl);add(bsubok);
lhl.setBounds(50,30,100,30);
ll1.setBounds(50,60,100,30);
ll2.setBounds(50,90,100,30);
ll3.setBounds(50,120,100,30);
ll4.setBounds(50,150,100,30);
ll5.setBounds(50,180,100,30);
ll6.setBounds(50,210,100,30);
la1.setBounds(200,60,100,30);
la2.setBounds(200,90,100,30);
la3.setBounds(200,120,100,30);
la4.setBounds(200,150,100,30);
la5.setBounds(200,180,100,30);
la6.setBounds(200,210,100,30);
ltl.setBounds(75,240,200,30);
bsubok.setBounds(100,280,100,30);
bsubok.addActionListener(this);}
}
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource()==bsubok)
{
StudentInfo.sf.setEnabled(true);
setVisible(false);
}
}
}
Program 27: WAP to implement System Clock.
public class AWT1
{
public static void main(String args[])
{
MyFrame mf = new MyFrame();
}
}
import java.util.*;
import java.awt.*;
import java.awt.event.*;
class MyFrame extends Frame implements ItemListener, ActionListener
{
Choice c1;
Button b1;
Checkbox cb1, cb2, cb3, cb4;
CheckboxGroup cbg1, cbg2;
Label lblTime;
TimeThread tt;
MyFrame(){
super("Sample Java Frame");
addWindowListener(new MyWindowAdapter());
setSize(400,300);
addControls();
setVisible(true);
tt = new TimeThread(this);
}
private void addControls()
{
setLayout(new FlowLayout());
lblTime = new Label("System Time Here");
add(lblTime);
c1 = new Choice();
c1.add("Ajmer");
c1.add("Jaipur");
c1.add("Alwar");
c1.add("Nasirabad");
c1.add("Bikaner");
c1.add("Kishangarh");
c1.add("Beawar");
c1.add("Bundi");
c1.add("Kota");
c1.add("Nagur");
c1.add("Jodhpur");
c1.add("Pali");
c1.addItemListener(this);
add(c1);
b1 = new Button("Click Me");
b1.addActionListener(this);
add(b1);
cbg1 = new CheckboxGroup();
cbg2 = new CheckboxGroup();
cb1 = new Checkbox("DOS",true,cbg1);
cb2 = new Checkbox("Windows",cbg1,true);cb3 = new Checkbox("Linux",cbg2,false);
cb4 = new Checkbox("Unix",cbg2,false);
add(cb1);
add(cb2);
add(cb3);
add(cb4);
cb1.addItemListener(this);
cb2.addItemListener(this);
cb3.addItemListener(this);
cb4.addItemListener(this);
}
public void itemStateChanged(ItemEvent ie)
{
if (ie.getSource() == c1)
{
if (c1.getSelectedIndex() != -1)
{
System.out.println(c1.getSelectedItem());
System.out.println(c1.getSelectedIndex());
}
}
else if (ie.getSource() == cb1)
{
c1.setEnabled(cb1.getState());
}
else if (ie.getSource() == cb3 || ie.getSource() == cb4)
{
System.out.println("Item Selected : " +
cbg2.getSelectedCheckbox().getLabel());
}
}
public void actionPerformed(ActionEvent ae)
{
if (ae.getSource() == b1)
{
int i;
for (i=0;i<c1.getItemCount();i++)
System.out.println(c1.getItem(i));
}
}String getTime()
{
Calendar cal = new GregorianCalendar();
int hour;
int minute;
int second;
hour = cal.get(Calendar.HOUR);
minute = cal.get(Calendar.MINUTE);
second = cal.get(Calendar.SECOND);
String timeStr = hour + ":" + minute + ":" + second;
return timeStr;
}
}
class TimeThread extends Thread
{
MyFrame mf;
TimeThread(MyFrame mf)
{
this.mf = mf;
start();
}
public void run()
{
while(true)
{
mf.lblTime.setText(mf.getTime());
try
{
Thread.sleep(970);
}
catch (InterruptedException e1)
{
}
}
}
}
import java.awt.event.*;
class MyWindowAdapter extends WindowAdapter
{
public void windowClosing(WindowEvent we){
System.exit(0);
}
}
Program 28: WAP to implement Interthread Communication.
class Consumer implements Runnable
{
Counter counter;
Thread t;
Consumer(Counter counter)
{
this.counter = counter;
t = new Thread(this);
t.start();
}
public void run()
{
int i;
while ((i = counter.getValue()) < 50);
}
}
class Counter
{
int value;
boolean valueSet;
Counter()
{
valueSet = false;
}
synchronized void setValue(int value)
{
try
{
if (valueSet == true)
{
wait();
}
this.value = value;
System.out.println("Value produced : " + value);
valueSet = true;
notify();
}
catch (InterruptedException e1){}}
synchronized int getValue()
{
try
{
if (valueSet == false)
{
wait();
}
System.out.println("Value consumed : " + value);
valueSet = false;
notify();
}
catch (InterruptedException e1){}
return value;
}
}
class Producer implements Runnable
{
Counter counter;
Thread t;
Producer(Counter counter)
{
this.counter = counter;
t = new Thread(this);
t.start();
}
public void run()
{
int i;
for (i=1;i<=50;i++)
counter.setValue(i);
}
}
public class InterThreadComm
{
public static void main(String args[])
{
Counter counter = new Counter();
Producer p = new Producer(counter);
Consumer c = new Consumer(counter);}
}
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