WEEK 1
1. Use Eclipse or Netbean platform and acquaint with the various menus.
Create a test project, add a test class and run it. See how you can use auto
suggestions, auto fill. Try code formatter and code refactoring like renaming
variables, methods and classes. Try debug step by step with java program to
find prime numbers between 1 to n.
class PrimeNumbers
{
public static void
main(String[] jbrec)
{
try
{
System.out.println("*****
PRIME NUMBERS *****");
Scanner objScanner =
new Scanner(System.in);
System.out.print("\nEnter
n Value:");
long n =
objScanner.nextInt();
for (long i = 2; i
<= n; i++)
{
boolean isprime =
isNumPrime(i);
if (isprime)
{
System.out.print(i +
" ");
}
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
public static
boolean isNumPrime(long number)
{
boolean result =
true;
for (long i = 2; i
<= number / 2; i++)
{
if ((number % i) !=
0)
{
result = true;
}
else
{
result = false;
break;
}
}
return result;
}
}
WEEK 2
1. Write a java program that prints all real and imaginary
solutions to the quadratic equation ax2+bx+c=0. Read in a, b, c and use the
quadratic formula
import java.io.*;
class Quadratic
{
public
static void main(String args[])throws IOException
{
double
x1,x2,disc,a,b,c;
InputStreamReader
obj=new InputStreamReader(System.in);
BufferedReader
br=new BufferedReader(obj);
System.out.println("enter
a,b,c values");
a=Double.parseDouble(br.readLine());
b=Double.parseDouble(br.readLine());
c=Double.parseDouble(br.readLine());
disc=(b*b)-(4*a*c);
if(disc==0)
{
System.out.println("roots
are real and equal ");
x1=x2=-b/(2*a);
System.out.println("roots
are "+x1+","+x2);
}
else
if(disc>0)
{
System.out.println("roots
are real and unequal");
x1=(-b+Math.sqrt(disc))/(2*a);
x2=(-b+Math.sqrt(disc))/(2*a);
System.out.println("roots
are "+x1+","+x2);
}
else
{
System.out.println("roots
are imaginary");
}
}
}
public class Sorting
{
String str=new String();
String[] names=new String[] {"King","Raja","Suresh","Arun"};
for(int i=0;i<names.length;i++)
System.out.println("Names are"+names[i]);
System.out.println("Sorting names are");
for(int i=0;i<names.length;i++)
for(int j=0;j<names.length;j++)
{
if(names[i].compareToIgnoreCase(names[j])<0)
{
str=names[i];
names[i]=names[j];
names[j]=str;
}
}
for(int i=0;i<names.length;i++)
System.out.println("Names are"+names[i]);
Output:
Java sorting Harish Ramesh Mahesh Rakesh
Sorted order is
Ramesh
Rakesh
Mahesh
Harish
Java sorting sai hari teja ravi sandeep
Sorted order is
teja
sandeep
sai
ravi
hari
3. Write a java program to accept a string
from user and display number of vowels, consonants, digits and special
characters present in each of the words of the given text.
import java.io.*;
public class classString
{
public static void main(String args[])
{
String str="This is java9 com SEEerverces123";
int
ln=str.length();
System.out.println("STring length is"+ln);
int
d=0,v=0,s=0,c=0;
for(int i=0;i<ln;i++)
{
char ch=str.charAt(i);
if(((ch>='a') && (ch<='z')) || ((ch>='A') &&
(ch<='Z')))
{
if(ch=='a'|| ch=='e'|| ch=='i' || ch=='o' || ch=='u' || ch=='A'||
ch=='E'|| ch=='I' || ch=='O' || ch=='U')
v++;
else
c++;
}
else if(ch>='0' && ch<='9')
d++;
else
s++;
}
System.out.println("Digits"+d);
System.out.println("Vowels"+v);
System.out.println("Consonents"+c);
System.out.println("Special Characters"+s);
}
}
OUTPUT:
STring length is32
Digits4
Vowels10
Consonents14
Special Characters4
WEEK 3
1. Write a java program to make rolling a pair of dice 10,000
times and counts the number of times doubles of are rolled for each different
pair of doubles.
Hint: Math.random()
import java.util.Random; // to use
random number generator
/**
* This program performs the following type of
experiment: Given a desired
* total roll, such as 7, roll a pair of dice
until the given total comes up,
* and count how many rolls are necessary. Now do that over and over, and
* find the average number of rolls. The number of times the experiment is
* repeated is given by the constant,
NUMBER_OF_EXPERIMENTS. The average is
* computed and printed out for each possible
roll = 2, 3, ..., 12.
*/
public class Dice
{
/**
* The number of times that the experiment "roll for a given
total"
* is to be repeated. The program
performs this many experiments, and
* prints the average of the result, for each possible roll value,
*/
public static final int NUMBER_OF_EXPERIMENTS = 10000;
public static void main(String[] args)
{
double average; // The average
number of rolls to get a given total.
System.out.println("Total On Dice Average Number of Rolls");
System.out.println("------------- -----------------------");
for ( int dice = 2; dice <=
12; dice++ )
{
average = getAverageRollCount( dice
);
System.out.printf("%10d%22.4f\n", dice, average);
// Use 10 spaces to output dice,
and use 22 spaces to output
// average, with 4 digits after
the decimal.
}
}
/**
* Find the average number of times a pair of dice must be rolled to get
* a given total. The experiment
of rolling for the given total is
* repeated NUMBER_OF_EXPERIMENTS times and the average number of rolls
* over all the experiments is computed.
* Precondition: The given total
must be be between 2 and 12, inclusive.
* @param roll the total that we want to get on the dice
* @return the average number of rolls that it takes to get the specified
* total
*/
public static double getAverageRollCount( int roll )
{
int rollCountThisExperiment; //
Number of rolls in one experiment.
int rollTotal; // Total number of
rolls in all the experiments.
double averageRollCount; //
Average number of rolls per experiment.
rollTotal = 0;
for ( int i = 0; i <
NUMBER_OF_EXPERIMENTS; i++ )
{
rollCountThisExperiment = rollFor(
roll );
rollTotal += rollCountThisExperiment;
}
averageRollCount = ((double)rollTotal) / NUMBER_OF_EXPERIMENTS;
return averageRollCount;
}
/**
* Simulates rolling a pair of dice until a given total comes up.
* Precondition: The desired total
is between 2 and 12, inclusive.
* @param N the total that we want to get on the dice
* @return the number of times the dice are rolled before the
* desired total occurs
* @throws IllegalArgumentException if the parameter, N, is not a number
* that could possibly come up
on a pair of dice
*/
public static int rollFor( int N )
{
if ( N < 2 || N > 12 )
throw new IllegalArgumentException("Impossible
total for a pair of dice.");
int die1, die2; // Numbers
between 1 and 6 representing the dice.
int roll; // Total showing
on dice.
int rollCt; // Number of
rolls made.
rollCt = 0;
do {
die1 = (int)(Math.random()*6) + 1;
die2 = (int)(Math.random()*6) + 1;
roll = die1 + die2;
rollCt++;
} while ( roll != N );
return rollCt;
}
}
// end DiceRollStats
2. Write java program that inputs 5 numbers, each between 10 and 100
inclusive. As each number is read display it only if it‘s not a duplicate of
any number already read display the complete set of unique values input after
the user enters each new value.
import
java.util.Scanner;
public
class Duplicate
{
public
static void main(String[] args)
{
int
a[]={0,0,0,0,0},t,i,j,s=0,r=0;
Scanner
z=new Scanner(System.in);
System.out.println("Enter
5 unique values between 10 & 100 ");
for(j=0;j<5;j++)
{
t=z.nextInt();
if(t>=10&&t<=100)
{
for(i=0;i<r;i++)
{
if(a[i]==t)
{
s++;
}
}
if(s>0)
{
System.out.println("Duplicate
value found retry");
s--;
j--;
continue;
}
else
{
a[j]=t;
r++;
}
}
else
{
System.out.println("value must be in
between 10 & 100");
j--;
}
}
System.out.print("The five unique values
are ");
for(i=0;i<5;i++)
{
System.out.print(a[i]+"
");
}
}
}
Output:-
Enter
5 unique values between 10 & 100
0
value
must be in between 10 & 100
10
20
10
Duplicate
value found retry
30
40
50
The
five unique values are 10 20 30 40 50
3. Write a java program to read the time
intervals (HH:MM) and to compare system time if the system time between your time
intervals print correct time and exit else try again to repute the same thing.
By using StringToknizer class.
import
java.util.*;
import
java.text.*;
class Tokenizer
{
static int[] cal(String y)
{
String a,b,x=":";
int i[] = {0,0};
StringTokenizer st=new
StringTokenizer(y,x);
a=(String) st.nextElement();
b=(String) st.nextElement();
i[0]=Integer.parseInt(a);
i[1]=Integer.parseInt(b);
return i;
}
}
public class GetCurrentDateTime
{
public static void main(String[] args) {
DateFormat dateFormat = new SimpleDateFormat("HH:mm");
Calendar cal = Calendar.getInstance();
String
y=dateFormat.format(cal.getTime());
while(true)
{
String x,t1,a,b;int
minute,hour;
int
HH[]={0,0},MM[]={0,0};
t1=dateFormat.format(cal.getTime());
int time1[]=Tokenizer.cal(t1);
hour=time1[0];
minute=time1[1];
System.out.println("Enter
the time intervels in HH MM fommat");
Scanner z=new
Scanner(System.in);
String t2=z.next();
String t3=z.next();
int time2[]=Tokenizer.cal(t2);
HH[0]=time2[0];
MM[0]=time2[1];
int time3[]=Tokenizer.cal(t3);
HH[1]=time3[0];
MM[1]=time3[1];
if(HH[0]>HH[1])
{
int t=HH[0];
HH[0]=HH[1];
HH[1]=t;
}
if(HH[0]==HH[1]&&MM[0]>MM[1])
{
int t=MM[0];
MM[0]=MM[1];
MM[1]=t;
}
if((hour>=HH[0]&&hour<HH[1])||(hour==HH[0]&&hour==HH[1])&&(minute>=MM[0]&&minute<=MM[1]))
{
System.out.println("Current
time is "+hour+" :
"+minute);
break;
}
else
{
System.out.println("Try again");
}
}
}
}
Week-4
1.
Write a java program to split a given text file into n parts. Name each
part as the name of the original file followed by .part<n> where n is the
sequence number of the part file.
import java.io.*;
import java.util.Scanner;
public class Split {
public static void main(String args[])
{
try{
//
Reading file and getting no. of files to be generated
String inputfile = "D:\\test.txt"; // Source File Name.
double nol = 2000.0; // No. of
lines to be split and saved in each output file.
File file = new File(inputfile);
Scanner scanner = new Scanner(file);
int
count = 0;
while (scanner.hasNextLine())
{
scanner.nextLine();
count++;
}
System.out.println("Lines in the file: " + count); // Displays no. of lines in the input
file.
double temp = (count/nol);
int
temp1=(int)temp;
int
nof=0;
if(temp1==temp)
{
nof=temp1;
}
else
{
nof=temp1+1;
}
System.out.println("No. of files to be generated :"+nof); //
Displays no. of files to be generated.
//---------------------------------------------------------------------------------------------------------
//
Actual splitting of file into smaller files
FileInputStream fstream = new FileInputStream(inputfile);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
for
(int j=1;j<=nof;j++)
{
FileWriter fstream1 = new FileWriter("C:/New
Folder/File"+j+".txt");
// Destination File Location
BufferedWriter out = new BufferedWriter(fstream1);
for (int i=1;i<=nol;i++)
{
strLine = br.readLine();
if (strLine!= null)
{
out.write(strLine);
if(i!=nol)
{
out.newLine();
}
}
}
out.close();
}
in.close();
}catch (Exception e)
{
System.err.println("Error: " + e.getMessage());
}
}
}
2. Write java program to create a super
class called Figure that receives the dimensions of two dimensional objects. It
also defines a method called area that computes the area of an object. The program
derives two subclasses from Figure. The first is Rectangle and second is
Triangle. Each of the sub class overridden area () so that it returns the area
of a rectangle and a triangle respectively.
// Using abstract methods and classes.
abstract class Figure {
double dim1;
double dim2;
Figure(double a, double b) {
dim1 = a;
dim2 = b;
}
// area is now an abstract method
abstract double area();
}
abstract class Figure {
double dim1;
double dim2;
Figure(double a, double b) {
dim1 = a;
dim2 = b;
}
// area is now an abstract method
abstract double area();
}
class
Rectangle extends Figure {
Rectangle(double a, double b) {
super(a, b);
}
// override area for rectangle
double area() {
System.out.println("Inside Area for Rectangle.");
return dim1 * dim2;
}
}
Rectangle(double a, double b) {
super(a, b);
}
// override area for rectangle
double area() {
System.out.println("Inside Area for Rectangle.");
return dim1 * dim2;
}
}
class
Triangle extends Figure {
Triangle(double a, double b) {
super(a, b);
}
// override area for right triangle
double area() {
System.out.println("Inside Area for Triangle.");
return dim1 * dim2 / 2;
}
}
Triangle(double a, double b) {
super(a, b);
}
// override area for right triangle
double area() {
System.out.println("Inside Area for Triangle.");
return dim1 * dim2 / 2;
}
}
class
AbstractAreas {
public static void main(String args[]) {
// Figure f = new Figure(10, 10); // illegal now
Rectangle r = new Rectangle(9, 5);
Triangle t = new Triangle(10, 8);
Figure figref; // this is OK, no object is created
figref = r;
System.out.println("Area is " + figref.area());
figref = t;
System.out.println("Area is " + figref.area());
}
}
public static void main(String args[]) {
// Figure f = new Figure(10, 10); // illegal now
Rectangle r = new Rectangle(9, 5);
Triangle t = new Triangle(10, 8);
Figure figref; // this is OK, no object is created
figref = r;
System.out.println("Area is " + figref.area());
figref = t;
System.out.println("Area is " + figref.area());
}
}
3. Write a Java program that creates three
threads. First thread displays “Good Morning” every one second, the second
thread displays “Hello” every two seconds and the third thread displays “Welcome” every three seconds
class A
extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(1000);
System.out.println("good morning");
}
}
catch(Exception e)
{ }
}
}
class B extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(2000);
System.out.println("hello");
}
}
catch(Exception e)
{ }
}
}
class C extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(3000);
System.out.println("welcome");
}
}
catch(Exception e)
{ }
}
}
class ThreadDemo
{
public static void main(String args[])
{
A t1=new A();
B t2=new B();
C t3=new C();
t1.start();
t2.start();
t3.start();
}
}
{
synchronized public void run()
{
try
{
while(true)
{
sleep(1000);
System.out.println("good morning");
}
}
catch(Exception e)
{ }
}
}
class B extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(2000);
System.out.println("hello");
}
}
catch(Exception e)
{ }
}
}
class C extends Thread
{
synchronized public void run()
{
try
{
while(true)
{
sleep(3000);
System.out.println("welcome");
}
}
catch(Exception e)
{ }
}
}
class ThreadDemo
{
public static void main(String args[])
{
A t1=new A();
B t2=new B();
C t3=new C();
t1.start();
t2.start();
t3.start();
}
}
Week-5
1. Write a Java program that correctly implements producer
consumer problem using the concept of inter thread communication
class Q
{
int n;
boolean valueSet=false;
synchronized int get()
{
if(!valueSet)
try
{
wait();
}
catch(InterruptedException e)
{
System.out.println("Interrupted Exception caught");
}
System.out.println("Got:"+n);
valueSet=false;
notify();
return n;
}
synchronized void put(int n)
{
if(valueSet)
try
{
wait();
}
catch(InterruptedException e)
{
System.out.println("Interrupted Exception caught");
}
this.n=n;
valueSet=true;
System.out.println("Put:"+n);
notify();
}
}
class Producer implements Runnable
{
Q q;
Producer(Q q)
{
this.q=q;
new Thread(this,"Producer").start();
}
public void run()
{
int i=0;
while(true)
{
q.put(i++);
}
}
}
class Consumer implements Runnable
{
Q q;
Consumer(Q q)
{
this.q=q;
new Thread(this,"Consumer").start();
}
public void run()
{
while(true)
{
q.get();
}
}
}
class ProdCons
{
public static void main(String[] args)
{
Q q=new Q();
new Producer(q);
new Consumer(q);
System.out.println("Press Control-c to stop");
}
}
Output:Put:1
Got:1
Put:2
Got:2
Put:3
Got:3
Put:4
Got:4
Put:5
Got:5
Put:6
Got:6
Put:7
Got:7
Put:8
Got:8
Put:9
Got:9
Put:10
Got:10
Put:11
Got:11
Put:12
Got:12
Put:13
Got:13
Put:14
Got:14
2. Write a java program to find and replace pattern in given
file.
import java.io.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
import java.io.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class PaternReplace
{
public static void main(String[] args) throws Exception
{
FileInputStream fis=new FileInputStream("F:\\java\\test.txt");
File file = new File("F:\\java\\test.txt");
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
StringBuffer source = new StringBuffer();
String line;
while ((line = bufferedReader.readLine()) != null) {
source.append(line);
source.append("\n");
}
fileReader.close();
System.out.println(source);
DataInputStream dis=new DataInputStream(System.in);
FileOutputStream fos=new FileOutputStream("F:\\java\\test.txt");
System.out.println("Enter to find word");
String find=dis.readLine();
System.out.println("Enter new word to replace");
String replace=dis.readLine();
Pattern pattern = Pattern.compile(find);
Matcher matcher = pattern.matcher(source);
String output = matcher.replaceAll(replace);
byte[] b=output.getBytes();
fos.write(b);
System.out.println("Output = " + output);
}
}
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class PaternReplace
{
public static void main(String[] args) throws Exception
{
FileInputStream fis=new FileInputStream("F:\\java\\test.txt");
File file = new File("F:\\java\\test.txt");
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
StringBuffer source = new StringBuffer();
String line;
while ((line = bufferedReader.readLine()) != null) {
source.append(line);
source.append("\n");
}
fileReader.close();
System.out.println(source);
DataInputStream dis=new DataInputStream(System.in);
FileOutputStream fos=new FileOutputStream("F:\\java\\test.txt");
System.out.println("Enter to find word");
String find=dis.readLine();
System.out.println("Enter new word to replace");
String replace=dis.readLine();
Pattern pattern = Pattern.compile(find);
Matcher matcher = pattern.matcher(source);
String output = matcher.replaceAll(replace);
byte[] b=output.getBytes();
fos.write(b);
System.out.println("Output = " + output);
}
}
3. Use inheritance to create an exception
super class called EexceptionA and exception sub class ExceptionB and
ExceptionC, where ExceptionB inherits from ExceptionA and ExceptionC inherits
from ExceptionB. Write a java program to demonstrate that the catch block for
type ExceptionA catches exception of type ExceptionB and ExceptionC.
class ExceptionsA{
static void genException(){
int num[]= {4,8,16,32,64,128,256};
int div[]= {2,0,4,4,0,8};
for(int i=0; i<num.length; i++){
System.out.println(num[i] +
"/" +
div[i] + "is" +
num[i]/div[i]);
}
}
}
class ExceptionsB extends
ExceptionsA{
ExceptionsB(){
String zero;
zero = ("Division by zero not allowed");
}
}
class ExceptionsC extends
ExceptionsB{
ExceptionsC(){
String array;
array = ("Divisor element not found");
}
}
class ExceptionTest{
public static void main(String[] args){
try {
ExceptionsA.genException();
}
catch (ArithmeticException zero){
System.out.printf("%s",zero);
}
catch (ArrayIndexOutOfBoundsException array){
System.out.printf("%s",array);
}//end catch
}//end class
}//end method
Week-6
1. Write a java program to convert an ArrayList to an Array.
import java.util.*;
class ArrayListToArray
{
public static void main(String args[])
{
ArrayList<String> a=new ArrayList<String>();
a.add("Gowtham");
a.add("Gutha's");
a.add("Java");
a.add("-");
a.add("demos");
a.add(".");
a.add("blogspot");
a.add(".");
a.add("com");
String st[]=a.toArray(new String[a.size()]);
System.out.println("The elements are");
for(String k:st)
System.out.println(k);
}
}
2. Write a Java Program for waving a Flag using Applets and
Threads
//<applet
code="Flag.class" height=300 width=300></applet>
//<applet code="Flag1.class" height=300 width=300></applet>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Flag1 extends Applet implements ActionListener {
Button but = new Button ("click");
double add = 0;
public void init () {
setBackground (Color.white);
add (but);
but.addActionListener (this);
}
public void paint (Graphics g) {
Dimension d = getSize();
int height = d.height, width = d.width;
int x[ ] = new int[2*width], y[ ] = new int[2*width];
for (int color=0; color<3; color++) {
switch(color) {
case 0: g.setColor (Color.orange); break;
case 1: g.setColor (Color.white); break;
case 2: g.setColor (Color.green);
}
// The following 2 lines are actually one:
int size = fillArrays
(x, y, width/8, 3*width/4, (1+color)*height/5, height/5, 5, add);
g.fillPolygon (x, y, size);
}
}
// The following 2 lines are actually one:
int fillArrays
(int h[ ], int v[ ], int xStart, int wd, int yStart, int ht, int step, double extra) {
int count = 0;
// top line of the colour band:
for (int i=xStart; (i<=xStart+wd); i += step) {
h[count] = i;
v[count++] = yStart+(int)(ht*Math.sin(i/(0.2*wd)+extra));
}
int n = count -1;
// The values of the bottom line are not calculated.
// They're equal to to the values of the top line + ht
for (int i=h[count-1]; i>=xStart; i-=step) {
h[count] = i;
v[count++] = v[n--]+ht;
}
return count;
}
public void actionPerformed (ActionEvent evt) {
add += 0.7;
repaint();
}
}
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Flag1 extends Applet implements ActionListener {
Button but = new Button ("click");
double add = 0;
public void init () {
setBackground (Color.white);
add (but);
but.addActionListener (this);
}
public void paint (Graphics g) {
Dimension d = getSize();
int height = d.height, width = d.width;
int x[ ] = new int[2*width], y[ ] = new int[2*width];
for (int color=0; color<3; color++) {
switch(color) {
case 0: g.setColor (Color.orange); break;
case 1: g.setColor (Color.white); break;
case 2: g.setColor (Color.green);
}
// The following 2 lines are actually one:
int size = fillArrays
(x, y, width/8, 3*width/4, (1+color)*height/5, height/5, 5, add);
g.fillPolygon (x, y, size);
}
}
// The following 2 lines are actually one:
int fillArrays
(int h[ ], int v[ ], int xStart, int wd, int yStart, int ht, int step, double extra) {
int count = 0;
// top line of the colour band:
for (int i=xStart; (i<=xStart+wd); i += step) {
h[count] = i;
v[count++] = yStart+(int)(ht*Math.sin(i/(0.2*wd)+extra));
}
int n = count -1;
// The values of the bottom line are not calculated.
// They're equal to to the values of the top line + ht
for (int i=h[count-1]; i>=xStart; i-=step) {
h[count] = i;
v[count++] = v[n--]+ht;
}
return count;
}
public void actionPerformed (ActionEvent evt) {
add += 0.7;
repaint();
}
}
3. Write a Java Program for Bouncing Ball
(The ball while moving down has to increase the size and decrease the size
while moving up)
import java.awt.*;
import javax.swing.*;
import java.util.ArrayList;
import java.util.List;
public class Ball extends JPanel implements Runnable {
List<Ball> balls = new ArrayList<Ball>();
Color color;
int diameter;
long delay;
private int x;
private int y;
private int vx;
private int vy;
public Ball(String ballcolor, int xvelocity, int yvelocity) {
if(ballcolor == "red") {
color = Color.red;
}
else if(ballcolor == "blue") {
color = Color.blue;
}
else if(ballcolor == "black") {
color = Color.black;
}
else if(ballcolor == "cyan") {
color = Color.cyan;
}
else if(ballcolor == "darkGray") {
color = Color.darkGray;
}
else if(ballcolor == "gray") {
color = Color.gray;
}
else if(ballcolor == "green") {
color = Color.green;
}
else if(ballcolor == "yellow") {
color = Color.yellow;
}
else if(ballcolor == "lightGray") {
color = Color.lightGray;
}
else if(ballcolor == "magenta") {
color = Color.magenta;
}
else if(ballcolor == "orange") {
color = Color.orange;
}
else if(ballcolor == "pink") {
color = Color.pink;
}
else if(ballcolor == "white") {
color = Color.white;
}
diameter = 30;
delay = 40;
x = 1;
y = 1;
vx = xvelocity;
vy = yvelocity;
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(color);
g.fillOval(x,y,30,30); //adds color to circle
g.setColor(Color.black);
g2.drawOval(x,y,30,30); //draws circle
}
public void run() {
while(isVisible()) {
try {
Thread.sleep(delay);
} catch(InterruptedException e) {
System.out.println("interrupted");
}
move();
repaint();
}
}
public void move() {
if(x + vx < 0 || x + diameter + vx > getWidth()) {
vx *= -1;
}
if(y + vy < 0 || y + diameter + vy > getHeight()) {
vy *= -1;
}
x += vx;
y += vy;
}
private void start() {
while(!isVisible()) {
try {
Thread.sleep(25);
} catch(InterruptedException e) {
System.exit(1);
}
}
Thread thread = new Thread(this);
thread.setPriority(Thread.NORM_PRIORITY);
thread.start();
}
public static void main(String[] args) {
Ball ball1 = new Ball("red",3,2);
Ball ball2 = new Ball("blue",6,2);
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(ball1);
f.getContentPane().add(ball2);
f.setSize(400,400);
f.setLocation(200,200);
f.setVisible(true);
new Thread(ball1).start();
new Thread(ball2).start();
}
}
Week-7
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class VisStackApplet extends JApplet implements ActionListener, Runnable {
ScrolledPanel visPanel; //Where to paint graphics
MyScrollPane msp;
Button executeButton;
Button historyButton;
TextArea userInputText;
TextArea history;
JFrame historyFrame;
JTextField statusLine;
MyStack theStack; // The data structure being demonstrated
Font stackFont;
int cellHeight = 20; // For drawing the stack.
int cellWidth = 200; // How wide to plot pink rectangles
int cellGap = 4; // vertical space between successive cells
int topMargin = 25; // Space above top of stack.
int fontSize = 16; // Height of font for displaying stack elemens.
int leftMargin = 20; // x value for left side of cells
int bottomMargin = 10; // Minimum space betw. bot. of visPanel and bot. of lowest cell.
int leftOffset = 5; // space between left side of cell and contents string.
int delay = 300; // default is to wait 300 ms between updates.
Thread displayThread = null;
public void init() {
setSize(300,300); // default size of applet.
visPanel = new ScrolledPanel();
visPanel.setPreferredSize(new Dimension(400,400));
msp = new MyScrollPane(visPanel);
msp.setPreferredSize(new Dimension(400,200));
Container c = getContentPane();
c.setLayout(new BorderLayout());
c.add(msp, BorderLayout.CENTER);
JPanel buttons = new JPanel();
buttons.setLayout(new FlowLayout());
JPanel controls = new JPanel();
controls.setLayout(new BorderLayout());
executeButton = new Button("Execute");
executeButton.addActionListener(this);
buttons.add(executeButton);
historyButton = new Button("History");
historyButton.addActionListener(this);
buttons.add(historyButton);
userInputText = new TextArea(";Enter commands here.");
statusLine = new JTextField();
statusLine.setBackground(Color.lightGray);
controls.add(buttons, BorderLayout.WEST);
controls.add(userInputText, BorderLayout.CENTER);
controls.add(statusLine, BorderLayout.SOUTH);
controls.setPreferredSize(new Dimension(400,100));
c.add(controls, BorderLayout.SOUTH);
c.validate();
theStack = new MyStack();
stackFont = new Font("Helvetica", Font.PLAIN, 20);
history = new TextArea("VisStackApplet history:\n", 20, 40);
}
class ScrolledPanel extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
paintStack(g);
}
}
class MyScrollPane extends JScrollPane {
MyScrollPane(JPanel p) {
super(p,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
}
}
class MyStack extends Vector {
int n; // number of elements in the stack
int npushes; // number of PUSH operations so far.
int npops; // number of POP operations so far.
void init() {
n = 0; npushes = 0; npops = 0;
}
void push(Object elt) {
add(n, elt);
n++;
npushes++;
}
Object pop() {
if (n == 0) { return null; }
Object o = lastElement();
n--;
npops++;
remove(n);
return o;
}
}
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("Execute")) {
displayThread = new Thread(this);
displayThread.start();
return;
}
if (e.getActionCommand().equals("History")) {
if (historyFrame == null) {
historyFrame = new JFrame("History of the VisStackApplet");
historyFrame.getContentPane().add(history);
historyFrame.setSize(new Dimension(300,300));
}
historyFrame.show();
System.out.println("Should have displayed the history window");
}
}
// The following is executed by a separate thread for the display.
public void run() {
String commands = userInputText.getText();
String line = "";
StringTokenizer lines;
for (lines = new StringTokenizer(commands, "\n\r\f");
lines.hasMoreTokens();) {
line = lines.nextToken();
process(line);
}
userInputText.setText(""); // Erase all the processed input.
}
// Helper function called by the run method above:
void process(String command) {
String arg = "";
StringTokenizer st = new StringTokenizer(command);
if (! st.hasMoreTokens()) { return; }
String firstToken = st.nextToken();
if (firstToken.startsWith(";")) { return; }
history.appendText(command + "\n");
statusLine.setText(command);
if (firstToken.equals("RESET")) {
theStack = new MyStack();
updateDisplay(); return;
}
if (firstToken.equals("SIZE")) {
String stats = "Current number of elements: " + theStack.n;
statusLine.setText(stats);
history.appendText("; " + stats + "\n");
return;
}
if (firstToken.equals("STATS")) {
String stats = "npushes: " + theStack.npushes +
"; npops: " + theStack.npops;
statusLine.setText(stats);
history.appendText("; " + stats + "\n");
return;
}
if (firstToken.equals("DELAY")) {
if (st.hasMoreTokens()) {
arg = st.nextToken();
try { delay =(new Integer(arg)).intValue(); }
catch(NumberFormatException e) {
delay = 0;
}
statusLine.setText("delay = " + delay);
}
history.appendText("; delay is now " + delay + "\n");
return;
}
if (firstToken.equals("PUSH")) {
arg = "UNDEFINED ELEMENT";
if (st.hasMoreTokens()) { arg = st.nextToken(); }
theStack.push(arg);
checkScrolledPanelSize();
updateDisplay(); return;
}
if (firstToken.equals("POP")) {
theStack.pop();
updateDisplay(); return;
}
history.appendText("[Unknown Stack command]\n");
statusLine.setText("Unknown Stack command: " + command);
}
// Here is a "middleman" method that updates the display waiting with
// the current time delay after each repaint request.
void updateDisplay() {
visPanel.repaint();
if (delay > 0) {
try {
Thread.sleep(delay);
}
catch(InterruptedException e) {}
}
}
// Here is the graphics method to actually draw the stack.
// It's called by the ScrolledPanel paintComponent method.
void paintStack(Graphics g) {
g.setFont(stackFont);
g.drawString( "Top of Stack", 10,20);
int ystart = theStack.n * (cellHeight + cellGap) + topMargin;
int ycentering = (cellHeight - fontSize) / 2;
int ypos = ystart;
for (Enumeration e = theStack.elements(); e.hasMoreElements();) {
String elt = (String) e.nextElement();
g.setColor(Color.pink);
g.fillRect(leftMargin, ypos, cellWidth, cellHeight);
g.setColor(Color.black);
g.drawString(elt, leftMargin + leftOffset, ypos+cellHeight - ycentering);
ypos -= (cellHeight + cellGap);
}
}
// The following computes the height of the display area needed by the current
// stack, and if it won't fit in the scrolled panel, it enlarges the scrolled panel.
// In the current implementation, the panel never gets smaller, even if the stack
// becomes empty. This could easily be changed.
void checkScrolledPanelSize() {
int heightNeeded = topMargin + theStack.n * (cellHeight + cellGap) + cellHeight+ bottomMargin;
Dimension d = visPanel.getPreferredSize();
int currentHeight = (int) d.getHeight();
int currentWidth = (int) d.getWidth();
if (heightNeeded > currentHeight) {
visPanel.setPreferredSize(new Dimension(currentWidth, heightNeeded));
visPanel.revalidate(); // Adjust the vertical scroll bar.
}
}
}
1.
Write a Java Program to Addition, Division, Multiplication and subtraction using JOptionPane dialog Box and Textfields.
Add this images to the files
Week-10
2. Write a Java code by using JtextField to read decimal value and converting a decimal number into binary number then print the binary value in another JtextField
import java.awt.*;
