Java - A Helpful Hand

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A Helpful Hand

Indus Institute of Technology & Engineering

MCA Department

ALL THE BEST

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Final programs (25) list which has to be

written in Lab observation book

Week 1:

1. Write a Java program that prints all real solutions to the quadratic equation ax2 + bx + c = 0.

Read in a, b, c and use the quadratic formula. If the discriminant b2 -4ac is negative, display a

message stating that there are no real solutions.

2. The Fibonacci sequence is defined by the following rule. The fist two values in the sequence

are 1 and 1. Every subsequent value is the run of the two values preceding it. Write a Java

program that uses both recursive and non recursive functions to print the nth value in the

Fibonacci sequence.

Week 2:

3. Write a Java program that prompts the user for an integer and then prints out all prime

numbers up to that. Integer.

4. Write a Java program to multiply two given matrices.

5. Write a Java Program that reads a line of integers, and then displays each integers, and the

sum of all the integers (use string tokenizer class)

Week 3:

6. Write a Java program that checks whether a given string is a palindrome or not. Ex: MADAM

is a palindrome.

7. Write a Java program for sorting a given list of names in ascending order.

8. Write a java program to make frequency count of words in a given text.

Week 4:

9. Write a Java program that reads on file name from the user then displays information about

whether the file exists, whether the file is readable, whether the file is writable, the type of file

and the length of the file in bytes.

10. Write a Java program that reads a file and displays a file and displays the file on the screen,

with a line number before each line.

11. Write a Java program that displays the number of characters, lines and words in a text file.

Week 5:

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12. Write a Java program that:

a) Implements stack ADT.

Week 6:

13. Write an applet that displays a simple message.

14. Develop an applet that displays receives an Integer in one text field, and computes its

factorial value and returns it in another text field, when the button named “ Compute “ is clicked.

Week 7:

15. Write a Java program that works as a simple calculator. Use a grid layout to arrange buttons

for the digits and for the + - X % operations. Add a text field to display the result.

Week 8:

16. Write a Java program for handling mouse events.

NOTE: write keyboard events in addition to

Written mouse events (already written)

Week 9:

17. Write a Java program for creating multiple 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.

18. Write a Java program that correctly implements producer consumer problem using the

concept of inter thread communication.

Week 11:

19. Write a Java program that implements a simple client/server application. The client sends

data to a server. The server receives the data, uses it to produce a result, and then sends the result

back to the client. The client displays the result on the console. For ex: The data sent from the

client is the radius of a circle, and the result produced by the server is the area of the circle.

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Week 12:

20. Write a Java program that allows the user to draw lines, rectangles and Ovals

21. Write a java Program to display the table using JTable Component.

22.Write a Swing program using JTable

23. Write a Swing Program using JTabbed.

24. Write a Swing Program using JTree.

25.Write a java program to display TextBox, Radio Buttons, CheckBox.

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OBJECT ORIENTED PROGRAMMING:

OOP Concepts:

The object oriented paradigm is built on the foundation laid by the

structured programming concepts. The fundamental change in OOP

is that a program is designed around the data being operated upon

rather upon the operations themselves. Data and its functions are

encapsulated into a single entity.OOP facilitates creating reusable

code that can eventually save a lot of work. A feature called

polymorphism permits to create multiple definitions for operators and

functions. Another feature called inheritance permits to derive new

classes from old ones. OOP introduces many new ideas and involves

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a different approach to programming than the procedural

programming.

Benefits of object oriented programming:

Data security is enforced.

Inheritance saves time.

User defined data types can be easily constructed.

Inheritance emphasizes inventions of new data types.

Large complexity in the software development cn be easily

managed.

Basic C++ Knowledge:

C++ began its life in Bell Labs, where Bjarne Stroustrup developed the

language in the early 1980s. C++ is a powerful and flexible

programming language. Thus, with minor exceptions, C++ is a

superset of the C Programming language.

The principal enhancement being the object –oriented concept of

a class.

A Class is a user defined type that encapsulates many important

mechanisms. Classes enable programmers to break an application

up into small, manageable pieces, or objects.

Basic concepts of Object oriented programming:

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Object:

Objects are the basic run time entities in an object-oriented

system.

thy may represent a person, a place, a bank account, a

table of data or any item that the program has to handle.

Class:

The entire set of data and code of an object can be made of

a user defined data type with the help of a class.

I fact, Objects are variables of the type class.

Once a class has been defined, we can create any number of

objects belonging to that class

A class is thus a collection of objects of similar type.

for example: mango, apple, and orange are members of the

class fruit.

ex: fruit mango; will create an object mango belonging

to the class fruit.

Data Abstraction and Encapsulation:

The wrapping up of data and functions in to a single unit is

known as encapsulation.

Data encapsulation is the most striking feature of a class.

The data is not accessible to the outside world, and only those

functions which are wrapped in the class can access.

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This insulation of the data from direct access by the program is

called data hiding.

Abstraction :

Abstraction referes to the act of representing essential features

without including the background details or explanations.

since the classes use the concept of data abstraction ,thy are

known as abstraction data type(ADT).

Inheritance :

Inheritance is the process by which objects of one class

acquire the properties of objects of another class. Inheritance

supports the concept of hierarchical classification.

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for example:

The bird 'robin ' is a part of the class 'flying bird' which is agian a

part of the class 'bird'. The concept of inheritance provide the idea

of reusability.

POLYMORPHISM:

Polymorphism is another important oop concept. Polymorphism

means the ability to take more than one form. an operation may

Bird

Attributes

Flying

bird

Attributes

:

Non flying

bird

Attributes:

Robin

Attributes

Swallow

Attributes

Penguin

Attributes

Kiwi

Attributes

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exhibit different instances. The behavior depends upon the types of

data used in the operation.

The process of making an operator to exhibit different behaviors

in different instance is known as operator overloading.

Polymorphism plays an important role in allowing objects having

different internal structures to share the same external interface.

Polymorphism is extensively used if implementing inheritance.

The Object-Oriented Approach

The fundamental idea behind object-oriented languages is to

combine into a single program entity both data and the functions

that operate on that data. Such an entity is called an object.

An object's functions, called member functions in C++ (because

they belong to a particular class of objects), typically provide the

only way to access its data. If you want to read a data item in an

object, you call a member function in the object. It will read the item

and return the value to you. You can't access the data directly. The

data is hidden, so it is safe from accidental alteration. Data and its

Shape

Circle Object

Box Object

Triangle Object

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functions are said to be encapsulated into a single entity.

Encapsulation and data hiding are key terms in the description of

object-oriented languages.

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Java History:

Java is a general-purpose; object oriented programming language

developed by Sun Microsystems of USA in 1991. Originally called “oak” by James

Gosling, one of the inventors if the language. This goal had a strong impact on the

development team to make the language simple, portable, highly reliable and

powerful language.

Java also adds some new features. While C++ is a superset of C. Java

is neither a superset nor a subset of C or C++.

C++

C

Java

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Process of building and running java application programs:

The way these tools are applied to build and run application programs is create a

program. We need create a source code file using a text editor. The source code is

then compiled using the java compiler javac and executed using the java interpreter

java. The java debugger jdb is used to find errors. A complied java program can be

converted into a source code.

Text Editor

Java Source

Code Javado

c

HTML

files

Javac

Java Class

File Javah

Header

Files

Java (only file

name)

Jdb

(database)

Java

progra

m

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SOLUTIONS

Program Statement :

Write a Java program that prints all real solutions to the quadratic

equation ax2+bx+c = 0. Read in a, b, c and use the quadratic

formula. If the discriminant

b2-4ac is negative, display a message stating that there are no real

solutions.

Program :

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);

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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);

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System.out.println("roots are "+x1+","+x2);

}

else

{

System.out.println("roots are imaginary");

}

}

}

Input & Output :

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Program Statement :

The Fibonacci sequence is defined by the following rule. The first 2

values in the sequence are 1, 1. Every subsequent value is the sum of

the 2 values preceding it. Write a Java program that uses both

recursive and non-recursive functions to print the nth value of the

Fibonacci sequence.

Program :

/*Non Recursive Solution*/

import java.util.Scanner;

class Fib {

public static void main(String args[ ]) {

Scanner input=new Scanner(System.in);

int i,a=1,b=1,c=0,t;

System.out.println("Enter value of t:");

t=input.nextInt();

System.out.print(a);

System.out.print(" "+b);

for(i=0;i<t-2;i++) {

c=a+b;

a=b;

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b=c;

System.out.print(" "+c);

}

System.out.println();

System.out.print(t+"th value of the series is: "+c);

}

}

Input & Output :

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/* Recursive Solution*/

import java.io.*;

import java.lang.*;

class Demo {

int fib(int n) {

if(n==1)

return (1);

else if(n==2)

return (1);

else

return (fib(n-1)+fib(n-2));

}

}

class RecFibDemo {

public static void main(String args[])throws IOException {

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InputStreamReader obj=new

InputStreamReader(System.in);

BufferedReader br=new BufferedReader(obj);

System.out.println("enter last number");

int n=Integer.parseInt(br.readLine());

Demo ob=new Demo();

System.out.println("fibonacci series is as follows");

int res=0;

for(int i=1;i<=n;i++) {

res=ob.fib(i);

System.out.println(" "+res);

}


System.out.println(n+"th value of the series is "+res);

}

}

Input & Output :

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Program Statement :

WAJP that prompts the user for an integer and then prints out all the

prime numbers up to that Integer.

Program :

Import java.util.*

class Test {

void check(int num) {

System.out.println ("Prime numbers up to "+num+" are:");

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

for (int j=2;j<i;j++) {

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if(i%j==0)

break;

else if((i%j!=0)&&(j==i-1))

System.out.print(“ “+i);

}

}

} //end of class Test

class Prime {


Test obj1=new Test();


System.out.println("Enter the value of n:");

int n=input.nextInt();

obj1.check(n);

}

}

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Input & Output :

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Program Statement :

WAJP that checks whether a given string is a palindrome or not. Ex:

MADAM is a palindrome.

Program :

import java.io.*;

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class Palind {

public static void main(String args[ ])throws IOException {

BufferedReader br=new BufferedReader(new

InputStreamReader(System.in));

System.out.println("Enter the string to check for palindrome:");

String s1=br.readLine();

StringBuffer sb=new StringBuffer();

sb.append(s1);

sb.reverse();

String s2=sb.toString();

if(s1.equals(s2))

System.out.println("palindrome");

else

System.out.println("not palindrome");

}

}

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Input &

Output

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Program Statement :

WAJP for sorting a given list of names in ascending order.

Program :

import java.io.*;

class Test {

int len,i,j;

String arr[ ];

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Test(int n) {

len=n;

arr=new String[n];

}

String[ ] getArray()throws IOException {

BufferedReader br=new BufferedReader (new


System.out.println ("Enter the strings U want to sort----");

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

arr[i]=br.readLine();

return arr;

}

String[ ] check()throws ArrayIndexOutOfBoundsException {

for (i=0;i<len-1;i++) {

for(int j=i+1;j<len;j++) {

if ((arr[i].compareTo(arr[j]))>0) {

String s1=arr[i];

arr[i]=arr[j];

arr[j]=s1;

}

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}

}

return arr;

}

void display()throws ArrayIndexOutOfBoundsException {

System.out.println ("Sorted list is---");

for (i=0;i<len;i++)

System.out.println(arr[i]);

}

} //end of the Test class

class Ascend {


Test obj1=new Test(4);

obj1.getArray();

obj1.check();

obj1.display();

}

}

Input & Output :

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Program Statement :

WAJP to multiply two given matrices.

Program :

import java.util.*;

class Test {

int r1,c1,r2,c2;

Test(int r1,int c1,int r2,int c2) {

this.r1=r1;

this.c1=c1;

this.r2=r2;

this.c2=c2;

}

int[ ][ ] getArray(int r,int c) {

int arr[][]=new int[r][c];

System.out.println("Enter the elements for "+r+"X"+c+"

Matrix:");


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

for(int j=0;j<c;j++)

arr[i][j]=input.nextInt();

return arr;

}

int[ ][ ] findMul(int a[ ][ ],int b[ ][ ]) {

int c[][]=new int[r1][c2];

for (int i=0;i<r1;i++)

for (int j=0;j<c2;j++) {

c[i][j]=0;

for (int k=0;k<r2;k++)

c[i][j]=c[i][j]+a[i][k]*b[k][j];

}

return c;

}

void putArray(int res[ ][ ]) {

System.out.println ("The resultant "+r1+"X"+c2+" Matrix is:");

for (int i=0;i<r1;i++) {

for (int j=0;j<c2;j++)

System.out.print(res[i][j]+" ");

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}

}

} //end of Test class

class MatrixMul {


Test obj1=new Test(2,3,3,2);

Test obj2=new Test(2,3,3,2);

int x[ ][ ],y[ ][ ],z[ ][ ];

System.out.println("MATRIX-1:");

x=obj1.getArray(2,3); //to get the matrix from user

System.out.println("MATRIX-2:");

y=obj2.getArray(3,2);

z=obj1.findMul(x,y); //to perform the multiplication

obj1.putArray(z); // to display the resultant matrix

}

}

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Input & Output :

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Program Statement :

WAJP that reads a line of integers and then displays each integer

and the sum of all integers. (use StringTokenizer class)

Program :

// Using StringTokenizer class

import java.lang.*;

import java.util.*;

class tokendemo {


String s="10,20,30,40,50";

int sum=0;

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StringTokenizer a=new StringTokenizer(s,",",false);

System.out.println("integers are ");

while(a.hasMoreTokens()) {

int b=Integer.parseInt(a.nextToken());

sum=sum+b;

System.out.println(" "+b);

}

System.out.println("sum of integers is "+sum);

}

}

// Alternate solution using command line arguments

class Arguments {


int sum=0;

int n=args.length;

System.out.println("length is "+n);

int arr[]=new int[n];

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

arr[i]=Integer.parseInt(args[i]);

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System.out.println("The enterd values are:");


System.out.println(arr[i]);

System.out.println("sum of enterd integers is:");


sum=sum+arr[i];

System.out.println(sum);

}

}

Input & Output :

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Program Statement :

WAJP that reads on file name from the user, then displays

information about whether the file exists, whether the file is readable,

wheteher the file is writable, the type of file and the length of the file

in bytes.

Program :

import java.io.File;

class FileDemo {

static void p(String s) {

System.out.println(s);

}


File f1 = new File(args[0]);

p("File Name: " + f1.getName());

p("Path: " + f1.getPath());

p("Abs Path: " + f1.getAbsolutePath());

p("Parent: " + f1.getParent());

p(f1.exists() ? "exists" : "does not exist");

p(f1.canWrite() ? "is writeable" : "is not writeable");

p(f1.canRead() ? "is readable" : "is not readable");

p("is " + (f1.isDirectory() ? "" : "not" + " a directory"));

p(f1.isFile() ? "is normal file" : "might be a named pipe");

p(f1.isAbsolute() ? "is absolute" : "is not absolute");

p("File last modified: " + f1.lastModified());

p("File size: " + f1.length() + " Bytes");

}

}

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Input & Output :

:

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Program Statement :

WAJP that reads a file and displays the file on the screen, with a line

number before each line.

Program :

import java.io.*;

class LineNum{

public static void main(String args[]){

String thisline;

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

{

try{

LineNumberReader br=new LineNumberReader(new

FileReader(args[i]));

while((thisline=br.readLine())!=null)

{

System.out.println(br.getLineNumber()+"."+thisline);

}

}catch(IOException e){

System.out.println("error:"+e);

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}

}

}

}

Input & Output :

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Program Statement :

WAJP that displays the number of characters, lines and words in a

text file.

Program :

import java.io.*;

public class FileStat {


long nl=0,nw=0,nc=0;

String line;


FileReader(args[0]));

while ((line=br.readLine())!=null) {

nl++;

nc=nc+line.length();

int i=0;

boolean pspace=true;

while (i<line.length()) {

char c=line.charAt(i++);

boolean cspace=Character.isWhitespace(c);

if (pspace&&!cspace)

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nw++;

pspace=cspace;

}

}

System.out.println("Number of Characters"+nc);

System.out.println("Number of Characters"+nw);

System.out.println("Number of Characters"+nl);

}}

// Alternate solution using StringTokenizer

import java.io.*;

import java.util.*;

public class FileStat {


long nl=0,nw=0,nc=0;

String line;


FileReader(args[0]));

while ((line=br.readLine())!=null) {

nl++;

nc=nc+line.length();

StringTokenizer st = new StringTokenizer(line);

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nw += st.countTokens();

}

System.out.println("Number of Characters"+nc);

System.out.println("Number of Characters"+nw);

System.out.println("Number of Characters"+nl);

}}

Input & Output :

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Program Statement :

WAJP that:

(a) Implements a Stack ADT

(b) Converts Infix expression to Postfix expression

(c) Evaluates a Postfix expression

Program :

import java.io.*;

interface stack

{

void push(int item);

int pop();

}

class Stackimpl

{

private int stck[];

private int top;

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Stackimpl(int size)

{

stck=new int[size];

top=-1;

}

void push(int item)

{

if(top==stck.length-1)

System.out.println("stack is full insertion is not

possible");

else

stck[++top]=item;

}

int pop()

{

if(top==-1)

{

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System.out.println("stack is empty deletion is not

possible");

return 0;

}

else

return stck[top--];

}

}

class Stackdemo

{

public static void main(String args[])throws IOException

{

int a[];



System.out.println("enter the size of the array");

int n=Integer.parseInt(br.readLine());

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Stackimpl obj1=new Stackimpl(n);

a=new int[n];

System.out.println("enter numbers into the stack");


a[i]=Integer.parseInt(br.readLine());

System.out.println("numbers are inserted");


obj1.push(a[i]);

System.out.println("The following numbers are poped

out.");


System.out.println(" "+obj1.pop());

}

}

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Input & Output :

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Program Statement :

Write an Applet that displays a simple message.

Program :

import java.awt.*;

import java.applet.*;

/*

<applet code = “HelloJava” width = 200 height = 60 >

</applet>

*/

public class HelloJava extends Applet {

public void paint(Graphics g) {

g.drawString(“Hello Java”, 10, 100);

}

}

Input & Output :

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Program Statement :

Write an Applet that computes the payment of a loan based on the

amount of the loan, the interest rate and the number of months. It

takes one parameter from the browser: Monthly rate; if true, the

interest rate is per month, otherwise the interest rate is annual.

Program :

import java.awt.*;

import java.awt.event.*;


/* <applet code = "LoanPayment" width=500 height=300 >

<param name = monthlyRate value=true>

</applet>

*/

public class LoanPayment extends Applet implements ActionListener

{

TextField amt_t, rate_t, period_t;

Button compute = new Button("Compute");

boolean monthlyRate;

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public void init() {

Label amt_l = new Label("Amount: ");

Label rate_l = new Label("Rate: ", Label.CENTER);

Label period_l = new Label("Period: ", Label.RIGHT);

amt_t = new TextField(10);

rate_t = new TextField(10);

period_t = new TextField(10);

add(amt_l);

add(amt_t);

add(rate_l);

add(rate_t);

add(period_l);

add(period_t);

add(compute);

amt_t.setText("0");

rate_t.setText("0");

period_t.setText("0");

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monthlyRate =

Boolean.valueOf(getParameter("monthlyRate"));

amt_t.addActionListener(this);

rate_t.addActionListener(this);

period_t.addActionListener(this);

compute.addActionListener(this);

}


double amt=0, rate=0, period=0, payment=0;

String amt_s, rate_s, period_s, payment_s;

g.drawString("Input the Loan Amt, Rate and Period in

each box and press Compute", 50,100);

try {

amt_s = amt_t.getText();

amt = Double.parseDouble(amt_s);

rate_s = rate_t.getText();

rate = Double.parseDouble(rate_s);

period_s = period_t.getText();

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period = Double.parseDouble(period_s);

}

catch (Exception e) { }

if (monthlyRate)

payment = amt * period * rate * 12 / 100;

else

payment = amt * period * rate / 100;

payment_s = String.valueOf(payment);

g.drawString("The LOAN PAYMENT amount is: ", 50, 150);

g.drawString(payment_s, 250, 150);

}

public void actionPerformed(ActionEvent ae) {

repaint();

}

}

Input & Output :

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Program Statement :

WAJP that works as a simple calculator. Use a grid layout to arrange

buttons for the digits and for the + - x / % operations. Add atext field

to display the result.

Program :

import javax.swing.*;

import java.awt.*;


//<applet code=Calculator height=300 width=200></applet>

public class Calculator extends JApplet {


CalculatorPanel calc=new CalculatorPanel();

getContentPane().add(calc);

}

}

class CalculatorPanel extends JPanel implements ActionListener {

JButton

n1,n2,n3,n4,n5,n6,n7,n8,n9,n0,plus,minus,mul,div,dot,equal;

static JTextField result=new JTextField("0",45);

JAVA

MCA-III Page 63

static String lastCommand=null;

JOptionPane p=new JOptionPane();

double preRes=0,secVal=0,res;

private static void assign(String no)

{

if((result.getText()).equals("0"))

result.setText(no);

else if(lastCommand=="=")

{

result.setText(no);

lastCommand=null;

}

else

result.setText(result.getText()+no);

}

public CalculatorPanel() {

setLayout(new BorderLayout());

result.setEditable(false);

result.setSize(300,200);

add(result,BorderLayout.NORTH);

JAVA

MCA-III Page 64

JPanel panel=new JPanel();

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

n7=new JButton("7");

panel.add(n7);

n7.addActionListener(this);


panel.add(n8);



panel.add(n9);


div=new JButton("/");

panel.add(div);

div.addActionListener(this);


panel.add(n4);



panel.add(n5);


JAVA

MCA-III Page 65


panel.add(n6);


mul=new JButton("*");

panel.add(mul);

mul.addActionListener(this);


panel.add(n1);



panel.add(n2);



panel.add(n3);


minus=new JButton("-");

panel.add(minus);

minus.addActionListener(this);

dot=new JButton(".");

panel.add(dot);

JAVA

MCA-III Page 66

dot.addActionListener(this);


panel.add(n0);


equal=new JButton("=");

panel.add(equal);

equal.addActionListener(this);

plus=new JButton("+");

panel.add(plus);

plus.addActionListener(this);

add(panel,BorderLayout.CENTER);

}

public void actionPerformed(ActionEvent ae)

{

if(ae.getSource()==n1) assign("1");

else if(ae.getSource()==n2) assign("2");







JAVA

MCA-III Page 67



else if(ae.getSource()==dot)

{

if(((result.getText()).indexOf("."))==-1)

result.setText(result.getText()+".");

}

else if(ae.getSource()==minus)

{

preRes=Double.parseDouble(result.getText());

lastCommand="-";

result.setText("0");

}

else if(ae.getSource()==div)

{


lastCommand="/";


}

else if(ae.getSource()==equal)

{

secVal=Double.parseDouble(result.getText());

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MCA-III Page 68

if(lastCommand.equals("/"))

res=preRes/secVal;

else if(lastCommand.equals("*"))

res=preRes*secVal;

else if(lastCommand.equals("-"))

res=preRes-secVal;

else if(lastCommand.equals("+"))

res=preRes+secVal;

result.setText(" "+res);

lastCommand="=";

}

else if(ae.getSource()==mul)

{


lastCommand="*";


}

else if(ae.getSource()==plus)

{


lastCommand="+";


JAVA

MCA-III Page 69

}

}

}

Input & Output :

JAVA

MCA-III Page 70

Program Statement :

WAJP for handling mouse events.

Program :

import java.awt.*;



/*

<applet code="MouseEvents" width=300 height=100>

</applet>

*/

public class MouseEvents extends Applet

implements MouseListener, MouseMotionListener {

String msg = "";

int mouseX = 0, mouseY = 0; // coordinates of mouse


addMouseListener(this);

addMouseMotionListener(this);

}

// Handle mouse clicked.

public void mouseClicked(MouseEvent me) {

// save coordinates

mouseX = 0;

mouseY = 10;

msg = "Mouse clicked.";

repaint();

}

// Handle mouse entered.

JAVA

MCA-III Page 71

public void mouseEntered(MouseEvent me) {

// save coordinates

mouseX = 0;

mouseY = 10;

msg = "Mouse entered.";

repaint();

}

// Handle mouse exited.

public void mouseExited(MouseEvent me) {

// save coordinates

mouseX = 0;

mouseY = 10;

msg = "Mouse exited.";

repaint();

}

// Handle button pressed.

public void mousePressed(MouseEvent me) {

// save coordinates

mouseX = me.getX();

mouseY = me.getY();

msg = "Down";

repaint();

}

// Handle button released.

public void mouseReleased(MouseEvent me) {

// save coordinates

mouseX = me.getX();

mouseY = me.getY();

msg = "Up";

repaint();

}

// Handle mouse dragged.

public void mouseDragged(MouseEvent me) {

// save coordinates

mouseX = me.getX();

mouseY = me.getY();

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MCA-III Page 72

msg = "*";

showStatus("Dragging mouse at " + mouseX + ", " + mouseY);

repaint();

}

// Handle mouse moved.

public void mouseMoved(MouseEvent me) {

// show status

showStatus("Moving mouse at " + me.getX() + ", " + me.getY());

}

// Display msg in applet window at current X,Y location.


g.drawString(msg, mouseX, mouseY);

}

}

Input & Output :

JAVA

MCA-III Page 73

Program Statement :

WAJP for creating multiple threads.

Program :

class NewThread implements Runnable {

String name; // name of thread

Thread t;

NewThread(String threadname) {

name = threadname;

JAVA

MCA-III Page 74

t = new Thread(this, name);

System.out.println("New thread: " + t);

t.start(); // Start the thread

}

// This is the entry point for thread.

public void run() {

try {

for(int i = 5; i > 0; i--) {

System.out.println(name + ": " + i);

Thread.sleep(1000);

}

} catch (InterruptedException e) {

System.out.println(name + "Interrupted");

}

System.out.println(name + " exiting.");

}

}

class MultiThreadDemo {

public static void main(String args[]) {

new NewThread("One"); // start threads

new NewThread("Two");

new NewThread("Three");

try {

// wait for other threads to end

Thread.sleep(10000);

} catch (InterruptedException e) {

System.out.println("Main thread Interrupted");

}

System.out.println("Main thread exiting.");

}

}

JAVA

MCA-III Page 75

Input & Output :

JAVA

MCA-III Page 76

JAVA

MCA-III Page 77

Program Statement :

WAJP that correctly implements Producer-Consumer problem using

the concept of Inter Thread Communication.

Program :

class Q {

int n;

boolean valueSet = false;

synchronized int get() {

if (!valueSet)

try {

wait();

} catch (InterruptedException e) { }

System.out.println(“Got: “ + n);

valueSet = false;

notify();

return n;

}

JAVA

MCA-III Page 78

synchronized void put(int n) {

if (valueSet)

try {

wait();

} catch (InterruptedException e) { }

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();

}

JAVA

MCA-III Page 79

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();

}

}

JAVA

MCA-III Page 80

}

class PC {

public static void main (String args[ ]) {

Q q = new Q();

new Producer(q);

new Consumer(q);

System.out.println(“Press Ctrl-C to stop”);

}

}

Input & Output :

JAVA

MCA-III Page 81

JAVA

MCA-III Page 82

Program Statement :

WAJP that lets users create Pie charts. Design your own user

interface (with Swings & AWT).

Program :

import java.awt.*;


/*<applet code=PiChart.class width=600 height=600></applet>*/

public class PiChart extends Applet {


setBackground(Color.green);

g.drawString("PI CHART",200,40);

g.setColor(Color.blue);

g.fillOval(50,50,150,150);

g.setColor(Color.white);

g.drawString("40%",130,160);

g.setColor(Color.magenta);

JAVA

MCA-III Page 83

g.fillArc(50,50,150,150,0,90);


g.drawString("25%",140,100);

g.setColor(Color.yellow);

g.fillArc(50,50,150,150,90,120);

g.setColor(Color.black);

g.drawString("35%",90,100);

g.setColor(Color.yellow);

g.fillOval(250,50,150,150);


g.drawString("15%",350,150);

g.setColor(Color.magenta);

g.fillArc(250,50,150,150,0,30);


g.drawString("5%",360,120);

g.setColor(Color.blue);

g.fillArc(250,50,150,150,30,120);


g.drawString("30%",330,100);


g.fillArc(250,50,150,150,120,180);

JAVA

MCA-III Page 84


g.drawString("50%",280,160);

}

}

Input & Output :

JAVA

MCA-III Page 85

JAVA

MCA-III Page 86

Program Statement :

WAJP that allows user to draw lines, rectangles and ovals.

Program :


import java.awt.Graphics;

public class choice extends JApplet

{

int i,ch;

public void init()

{

String input;

input=JOptionPane.showInputDialog("enter your

choice(1-lines,2-rectangles,3-ovals)");

ch=Integer.parseInt(input);

}

public void paint(Graphics g)

{

switch(ch)

{

case 1:{

JAVA

MCA-III Page 87

for(i=1;i<=10;i++)

{

g.drawLine(10,10,250,10*i);

}

break;

}

case 2:{

for(i=1;i<=10;i++)

{

g.drawRect(10*i,10*i,50+10*i,50+10*i);

}

break;

}

case 3:{

for(i=1;i<=10;i++)

{

g.drawOval(10*i,10*i,50+10*i,50+10*i);

}

break;

}}}}

JAVA

MCA-III Page 88

Input & Output :

JAVA

MCA-III Page 89

JAVA

MCA-III Page 90

Program Statement :

WAJP that implements a simple client/server application. The client

sends data to a server. The server receives the data, uses it to

produce a result and then sends the result back to the client. The

client displays the result on the console. For ex: The data sent from

the client is the radius of a circle and the result produced by the

server is the area of the circle.

Program :

// Server Program

import java.io.*;

import java.net.*;

import java.util.*;

public class Server {

public void static main (String args [ ] ) {

try {

// create a server socket

ServerSocket s = new ServerSocket(8000);

// start listening for connections on srver socket

JAVA

MCA-III Page 91

Socket connectToClient = s.accept();

// create a buffered reader stream to get data from

client

BufferedReader isFromClient = new

BufferedReader(new InputStreamReader

(connectToClient.getInputStream()));

// create a buffer reader to send result to client

PrintWriter osToClient = new

PrintWriter(connectToClient.getOutputStream(), true);

// continuously read from client, process, send back

while (true) {

// read a line and create string tokenizer

StringTokenizer st = new

StringTokenizer(isFromClient.readLine());

//convert string to double

double radius = new

Double(st.nextToken()).doubleValue();

// display radius on console

JAVA

MCA-III Page 92

System.out.println(“Radius received from client:

“ + radius);

// comput area

double area = radius * radius *Math.PI;

// send result to client

osToClient.println(area);

// print result on console

System.out.println(“Area found: “ +area);

}

} catch (IOException e) {

System.err.println(e);

}

}

}

// Client Program

import java.io.*;

JAVA

MCA-III Page 93

import java.net.*;

import java.util.*;

public class Client {

public void static main (String args [ ] ) {

try {

// create a socket to connect to server

Socket connectToServer = new Socket(“local host”,

8000);

// create a buffered input stream to get result from

server

BufferedReader isFromServer = new

BufferedReader(new InputStreamReader

(connectToServer.getInputStream()));

// create a buffer output stream to send data to

server

PrintWriter osToServer = new

PrintWriter(connectToClient.getOutputStream(), true);

// continuously send radius and get area

while (true) {


JAVA

MCA-III Page 94

System.out.print(“Please enter a radius: “);

double radius =input.nextDouble();

// display radius on console

osToServer.println(radius);

// get area from server

StringTokenizer st = new

StringTokenizer(isFromServer.readLine());

// convert string to double

Double area = new

Double(st.nextToken()).doubleValue();

// print result on console

System.out.println(“Area received from the

server is: “ +area);

}

} catch (IOException e) {

System.err.println(e);

}

}

}

JAVA

MCA-III Page 95

Input & Output :

JAVA

MCA-III Page 96

JAVA

MCA-III Page 97

Program Statement :

WAJP that illustrates how runtime polymorphism is achieved.

Program :

class Figure {

double dim1;

double dim2;

Figure(double a, double b) {

dim1 = a;

dim2 = b;

}

double area() {

System.out.println("Area for Figure is undefined.");

return 0;

}

}

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;

}

}

class Triangle extends Figure {

Triangle(double a, double b) {

JAVA

MCA-III Page 98

super(a, b);

}

// override area for right triangle

double area() {

System.out.println("Inside Area for Triangle.");

return dim1 * dim2 / 2;

}

}

class FindAreas {


Figure f = new Figure(10, 10);

Rectangle r = new Rectangle(9, 5);

Triangle t = new Triangle(10, 8);

Figure figref;

figref = r;

System.out.println("Area is " + figref.area());

figref = t;


figref = f;


}

}

JAVA

MCA-III Page 99

Input & Output :

JAVA

MCA-III Page 100

Program Statement :

WAJP to generate a set of random numbers. Find its sum and

average. The program should also display ‘*’ based on the random

numbers generated.

Program :

import java.util.*;

class RandNum {

public static void main(String ax[ ]) {

int a[ ]=new int[5];

int sum=0;

Random r=new Random();

for (int i=0;i<5;i++) {

a[i]=r.nextInt(10);

System.out.print(a[i]);

for(int y=0;y<a[i];y++)

System.out.print(" *");

System.out.println("");

}

for(int i=0;i<5;i++)

sum=sum+a[i];

JAVA

MCA-III Page 101

System.out.println("Sum="+sum);

System.out.println("Avg="+(double)sum/a.length);

}

}

Input & Output :

JAVA

MCA-III Page 102

JAVA

MCA-III Page 103

Program Statement :

WAJP to create an abstract class named Shape, that contains an

empty method named numberOfSides(). Provide three classes

named Trapezoid, Triangle and Hexagon, such that each one of

the classes contains only the method numberOfSides(), that

contains the number of sides in the given geometrical figure.

Program :

abstract class Shape

{

abstract void numberOfSides();

}

class Trapezoid extends Shape{

JAVA

MCA-III Page 104

void numberOfSides() {

System.out.println(" Trapezoidal has four sides");

}

}

class Triangle extends Shape {

void numberOfSides()

{

System.out.println("Triangle has three sides");

}

}

class Hexagon extends Shape {

void numberOfSides()

{

System.out.println("Hexagon has six sides");

}

}

class ShapeDemo {


Trapezoid t=new Trapezoid();

Triangle r=new Triangle();

Hexagon h=new Hexagon();

Shape s;

JAVA

MCA-III Page 105

s=t;

s.numberOfSides();

s=r;

s.numberOfSides();

s=h;

s.numberOfSides();

}

}

Input & Output :

JAVA

MCA-III Page 106

Program Statement :

WAJP to implement a Queue, using user defined Exception Handling

(also make use of throw, throws).

Program :


class ExcQueue extends Exception {

ExcQueue(String s) {

super(s);

}

}

class Queue {

int front,rear;

int q[ ]=new int[10];

Queue() {

rear=-1;

front=-1;

JAVA

MCA-III Page 107

}

void enqueue(int n) throws ExcQueue {

if (rear==9)

throw new ExcQueue("Queue is full");

rear++;

q[rear]=n;

if (front==-1)

front=0;

}

int dequeue() throws ExcQueue {

if (front==-1)

throw new ExcQueue("Queue is empty");

int temp=q[front];

if (front==rear)

front=rear=-1;

else

front++;

return(temp);

}

}

JAVA

MCA-III Page 108

class UseQueue {


Queue a=new Queue();

try {

a.enqueue(5);

a.enqueue(20);

} catch (ExcQueue e) {

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

}

try {

System.out.println(a.dequeue());



} catch(ExcQueue e) {

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

}

}

}

Input & Output :

JAVA

MCA-III Page 109

JAVA

MCA-III Page 110

Program Statement :

WAJP that creates 3 threads by extending Thread class. First thread

displays “Good Morning” every 1 sec, the second thread displays

“Hello” every 2 seconds and the third displays “Welcome” every 3

seconds. (Repeat the same by implementing Runnable)

Program :

// Using Thread class

class One extends Thread {

public void run() {

for ( ; ; ) {

try{

sleep(1000);

}catch(InterruptedException e){}

System.out.println("Good Morning");

}

}

}

class Two extends Thread {

public void run() {

JAVA

MCA-III Page 111

for ( ; ; ) {

try{

sleep(2000);


System.out.println("Hello");

}

}

}

class Three extends Thread {

public void run() {

for ( ; ; ) {

try{

sleep(3000);


System.out.println("Welcome");

}

}

}

class MyThread {


JAVA

MCA-III Page 112

Thread t = new Thread();

One obj1=new One();

Two obj2=new Two();

Three obj3=new Three();

Thread t1=new Thread(obj1);



t1.start();

try{

t.sleep(1000);


t2.start();

try{

t.sleep(2000);


t3.start();

try{

t.sleep(3000);


}

JAVA

MCA-III Page 113

}

// Using Runnable interface

class One implements Runnable {

One( ) {

new Thread(this, "One").start();

try{

Thread.sleep(1000);


}

public void run() {

for ( ; ; ) {

try{

Thread.sleep(1000);


System.out.println("Good Morning");

}

}

}

JAVA

MCA-III Page 114

class Two implements Runnable {

Two( ) {

new Thread(this, "Two").start();

try{

Thread.sleep(2000);


}

public void run() {

for ( ; ; ) {

try{

Thread.sleep(2000);


System.out.println("Hello");

}

}

}

class Three implements Runnable {

Three( ) {

JAVA

MCA-III Page 115

new Thread(this, "Three").start();

try{

Thread.sleep(3000);


}

public void run() {

for ( ; ; ) {

try{

Thread.sleep(3000);


System.out.println("Welcome");

}

}

}

class MyThread {


One obj1=new One();

Two obj2=new Two();

Three obj3=new Three();

}

JAVA

MCA-III Page 116

}

Input & Output :

JAVA

MCA-III Page 117

Program Statement :

WAJP that will compute the following series:

(a) 1 + 1/2 + 1/3+ …….+ 1/n

(b) 1 + 1/2 + 1/ 22 + 1/ 23 + … … + 1/ 2n

(c) ex = 1 + x/1! + x2/2! + x3/3! + … …

Program :

// (a) 1 + 1/2 + 1/3+ …….+ 1/n


class Series1 {

public static void main(String arg[ ]) {

int n;

double sum=0,i;

Scanner input= new Scanner(System.in);

System.out.println("enter value of n:");

n=input.nextInt();

for(i=1;i<=n;i++)

sum=sum+(double)(1/i);

System.out.println("Result:"+sum);

JAVA

MCA-III Page 118

}

}

Input & Output :

// (b)1 + 1/2 + 1/ 22 + 1/ 23 + … … + 1/ 2n


class Series2 {


int n;

double sum=0,i;



n=input.nextInt();

JAVA

MCA-III Page 119

for(i=1;i<=n;i++)

sum=sum+(double)(1/Math.pow(2,i-1));

System.out.println("Result:"+sum);

}

}

Input & Output :

JAVA

MCA-III Page 120

// (c) ex = 1 + x/1! + x2/2! + x3/3! + … …

import java.util.*;

class Series3{


int n,x;

double sum=0,i,d=1;



n=input.nextInt();

System.out.println("enter value of x:");

x=input.nextInt();

for (i=1;i<=n;i++) {

sum=sum+(double)((Math.pow(x,i-1)/d));

d=d*i;

}

System.out.println("Result :"+sum);

}

}

JAVA

MCA-III Page 121

Input & Output :

JAVA

MCA-III Page 122

Program Statement :

WAJP to do the following:

(a) To output the question “Who is the inventor of Java?”

(b) To accept an answer

(c) To printout “GOOD” and then stop if the answer is correct

(d) To output the message “TRY AGAIN”, if the answer is

wrong

(e) To display the correct answer, when the answer is wrong

even at the third attempt

Program :

import java.io.*;

class Ask {

public static void main(String a[ ])throws Exception {

String str1,str2;

int count=0;

str1="James Gosling";



System.out.println("Who is the inventor of Java ?");

while(count!=3) {

JAVA

MCA-III Page 123

str2=br.readLine();

if(str1.equalsIgnoreCase(str2)) {

System.out.println("!!! GOOD !!!");

break;

}

else {

if(count<2)

System.out.println("TRY AGAIN !");

count++;

}

}

if(count==3)

System.out.println("Correct Answer is : "+str1);

}

}

Input & Output :

JAVA

MCA-III Page 124

:

JAVA

MCA-III Page 125

Program Statement :

WAJP to transpose a matrix using ‘arraycopy’ command.

Program :

class TransMatrix {

public static void main(string args[ ]) {

int i,j,k=0;

int rows,cols,r,c;

int a[ ][ ]={{1,2,3,4},{5,6,7,8}};

rows=a.length;

cols=a[0].length;

int b[ ][ ]=new int[rows*cols];

int s[ ]=new int[rows*cols];

int d[ ]=new int[rows*cols];

for (i=0;i<rows;i++)

for (j=0;j<cols;j++,k++)

s[k]=a[i][j];

i=j=k=r=c=0;

JAVA

MCA-III Page 126

while(r<rows) {

while(c<cols) {

System.arraycopy(s,i,d,i,l);

b[j++][k]=d[i++];

c++;

}

j=c=0;

k++;

t++;

}

System.out.println("a matrix:");

for (i=0;i<rows;i++) {

for(j=0;j<cols;j++)

System.out.print(" "+a[i][j]);


}

System.out.println("\nb matrix:");

for(i=0;i<cols;i++) {

for(j=0;j<rows;j++)

System.out.print(" "+b[i][j]);

JAVA

MCA-III Page 127


}

}

}

Input & Output :

INPUT :

OUTPUT :

JAVA

MCA-III Page 128

Program Statement :

Create an inheritance hierarchy of Rodent, Mouse, Gerbil, Hamster

etc. In the base class provide methods that are common to all

Rodents and override these in the derived classes to perform

different behaviors, depending on the specific type of Rodent.

Create an array of Rodent, fill it with different specific types of

Rodents and call your base class methods.

Program :

import java.util.Random;

class Rodent{

void place() {}

void tail() {}

void eat() {}

public static Rodent randRodent(){

Random rr=new Random();

switch (rr.nextInt(4)) {

case 0: return new Mouse();

case 1: return new Gerbil ();

case 2: return new Hamster ();

JAVA

MCA-III Page 129

case 3: return new Beaver ();

}

return new Rodent();

}

}

class Mouse extends Rodent {

void place() {

System.out.println(“Mice are found all over the

world”);

}

void tail() {

System.out.println(“Mice have long and hairless

tail”);

}

void eat() {

System.out.println(“Mice eat cardboards,

papers, clothes”);

}

}

class Gerbil extends Rodent {

void place() {

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System.out.println(“Gerbils are found in arid

parts of Africa and Asia”);

}

void tail() {

System.out.println(“Gerbils have long tail”);

}

void eat() {

System.out.println(“Gerbils eat seeds, roots,

insects, parts of plants”);

}

}

class Hamster extends Rodent {

void place() {

System.out.println(“Hamsters are found in

Western Europe to China – Dry regions only”);

}

void tail() {

System.out.println(“Hamsters have short tail”);

}

void eat() {

System.out.println(“Hamsters eat cereals”);

}

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}

class Beaver extends Rodent {

void place() {

System.out.println(“Beavers are found in

Northern Europe and North America”);

}

void tail() {

System.out.println(“Beavers have broad tail”);

}

void eat() {

System.out.println(“Beavers eat bark”);

}

}

public class Rodents{


Rodent r[] = new Rodent[6];

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

r[i] = Rodent.randRodent();

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

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r[i].place();

r[i].tail();

r[i].eat();

}

}

}

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Input & Output :

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MCA-III Page 134

Program Statement :

WAJP to print a chessboard pattern.

Program :

import java.awt.*;


public class ChessBoard extends Applet {

/* This applet draws a red-and-black checkerboard.

It is assumed that the size of the applet is 160

by 160 pixels.

*/

/* <applet code="ChessBoard.class" width=200 height=160>

</applet> */


int row; // Row number, from 0 to 7

int col; // Column number, from 0 to 7

int x,y; // Top-left corner of square

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for ( row = 0; row < 8; row++ ) {

for ( col = 0; col < 8; col++) {

x = col * 40;

y = row * 40;

if ( (row % 2) == (col % 2) )


else


g.fillRect(x, y, 40, 40);

}

} // end for row

} // end paint()

} // end class

Input & Output :

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JAVA

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SOME OTHER PROGRAMS

APPLET PROGRAMS

1. // Demonstrate BorderLayout.

import java.awt.*;


import java.util.*;

/*

<applet code="BorderLayoutDemo" width=400 height=200>

</applet>

*/

public class BorderLayoutDemo extends Applet {



add(new Button("This is across the top."),

BorderLayout.NORTH);

add(new Label("The footer message might go here."),

BorderLayout.SOUTH);

add(new Button("Right"), BorderLayout.EAST);

add(new Button("Left"), BorderLayout.WEST);

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String msg = "The reasonable man adapts " +

"himself to the world;\n" +

"the unreasonable one persists in " +

"trying to adapt the world to himself.\n" +

"Therefore all progress depends " +

"on the unreasonable man.\n\n" +

" - George Bernard Shaw\n\n";

add(new TextArea(msg), BorderLayout.CENTER);

}

}

2. // Demonstrate Buttons

import java.awt.*;



/*

<applet code="ButtonDemo" width=250 height=150>

</applet>

*/

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public class ButtonDemo extends Applet implements ActionListener {

String msg = "";

Button yes, no, maybe;

TextField f1;


yes = new Button("Yes");

no = new Button("No");

maybe = new Button("Undecided");

f1=new TextField(19);

add(yes);

add(no);

add(maybe);

add(f1);

yes.addActionListener(this);

no.addActionListener(this);

maybe.addActionListener(this);

}


String str = ae.getActionCommand();

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if(str.equals("Yes")) {

msg = "You pressed Yes.";

f1.setText(str);

}

else if(str.equals("No")) {

msg = "You pressed No.";

}

else {

msg = "You pressed Undecided.";

}

repaint();

}


g.drawString(msg, 6, 100);

}

}

3. // Demonstrate Buttons

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import java.awt.*;



/*

<applet code="ButtonDemo" width=250 height=150>

</applet>

*/

public class ButtonDemo1 extends Frame implements

ActionListener {

static String msg = "";

static Button yes, no, maybe;

public void ButtonDemo1() {

yes = new Button("Yes");

no = new Button("No");

maybe = new Button("Undecided");

add(no);

add(maybe);

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yes.addActionListener(this);

no.addActionListener(this);

maybe.addActionListener(this);

}


String str = ae.getActionCommand();

if(str.equals("Yes")) {

msg = "You pressed Yes.";

}

else if(str.equals("No")) {

msg = "You pressed No.";

}

else {

msg = "You pressed Undecided.";

}

}

public static void main(String s[]) {

ButtonDemo1 b1=new ButtonDemo1();

b1.setSize(300,300);

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b1.setVisible(true);

b1.add(yes);

b1.add(no);

b1.add(maybe);

System.out.println(msg);

}

}

4. // Demonstrate CardLayout.

import java.awt.*;



/*

<applet code="CardLayoutDemo" width=300 height=100>

</applet>

*/

public class CardLayoutDemo extends Applet

implements ActionListener, MouseListener {

Checkbox Win98, winNT, solaris, mac;

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Panel osCards;

CardLayout cardLO;

Button Win, Other;


Win = new Button("Windows");

Other = new Button("Other");

add(Win);

add(Other);

cardLO = new CardLayout();

osCards = new Panel();

osCards.setLayout(cardLO); // set panel layout to card layout

Win98 = new Checkbox("Windows 98", null, true);

winNT = new Checkbox("Windows NT");

solaris = new Checkbox("Solaris");

mac = new Checkbox("MacOS");

// add Windows check boxes to a panel

Panel winPan = new Panel();

winPan.add(Win98);

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winPan.add(winNT);

// Add other OS check boxes to a panel

Panel otherPan = new Panel();

otherPan.add(solaris);

otherPan.add(mac);

// add panels to card deck panel

osCards.add(winPan, "Windows");

osCards.add(otherPan, "Other");

// add cards to main applet panel

add(osCards);

// register to receive action events

Win.addActionListener(this);

Other.addActionListener(this);

// register mouse events

addMouseListener(this);

}

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// Cycle through panels.

public void mousePressed(MouseEvent me) {

cardLO.next(osCards);

}

// Provide empty implementations for the other MouseListener

methods.


}

public void mouseEntered(MouseEvent me) {

}

public void mouseExited(MouseEvent me) {

}

public void mouseReleased(MouseEvent me) {

}


if(ae.getSource() == Win) {

cardLO.show(osCards, "Windows");

}

else {

cardLO.show(osCards, "Other");

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}

}

}

5. // Demonstrate check box group.

import java.awt.*;



/*

<applet code="CBGroup" width=250 height=200>

</applet>

*/

public class CBGroup extends Applet implements ItemListener {

String msg = "";


CheckboxGroup cbg;


cbg = new CheckboxGroup();

Win98 = new Checkbox("Windows 98", cbg, true);

winNT = new Checkbox("Windows NT", cbg, false);

solaris = new Checkbox("Solaris", cbg, false);

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mac = new Checkbox("MacOS", cbg, false);

add(Win98);

add(winNT);

add(solaris);

add(mac);

Win98.addItemListener(this);

winNT.addItemListener(this);

solaris.addItemListener(this);

mac.addItemListener(this);

}

public void itemStateChanged(ItemEvent ie) {

repaint();

}

// Display current state of the check boxes.


msg = "Current selection: ";

msg += cbg.getSelectedCheckbox().getLabel();


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}

}

6. // Demonstrate check boxes.

import java.awt.*;



/*

<applet code="CheckboxDemo" width=250 height=200>

</applet>

*/

public class CheckboxDemo extends Applet implements

ItemListener {

String msg = "";







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add(Win98);

add(winNT);

add(solaris);

add(mac);





}


repaint();

}

// Display current state of the check boxes.


msg = "Current state: ";


msg = " Windows 98: " + Win98.getState();


msg = " Windows NT: " + winNT.getState();

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msg = " Solaris: " + solaris.getState();


msg = " MacOS: " + mac.getState();


}

}

7. // Demonstrate Choice lists.

import java.awt.*;



/*

<applet code="ChoiceDemo" width=300 height=180>

</applet>

*/

public class ChoiceDemo extends Applet implements ItemListener

{

Choice os, browser;

String msg = "";


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os = new Choice();

browser = new Choice();

// add items to os list

os.add("Windows 98");

os.add("Windows NT");

os.add("Solaris");

os.add("MacOS");

// add items to browser list

browser.add("Netscape 1.1");

browser.add("Netscape 2.x");



browser.add("Internet Explorer 2.0");



browser.add("Lynx 2.4");

browser.select("Netscape 4.x");

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// add choice lists to window

add(os);

add(browser);

// register to receive item events

os.addItemListener(this);

browser.addItemListener(this);

}


repaint();

}

// Display current selections.


msg = "Current OS: ";

msg += os.getSelectedItem();


msg = "Current Browser: ";

msg += browser.getSelectedItem();


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}

}

8. import java.applet.Applet;

import java.awt.*;

/*

<applet code="DialogDemo" width=250 height=200>

</applet>

*/

// Create frame window.

public class DialogDemo extends Applet {

Frame f;


f = new MenuFrame("Menu Demo");

int width = Integer.parseInt(getParameter("width"));

int height = Integer.parseInt(getParameter("height"));

setSize(width, height);

f.setSize(width, height);

f.setVisible(true);

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}

public void start() {

f.setVisible(true);

}

public void stop() {

f.setVisible(false);

}

}

9. // Use left-aligned flow layout.

import java.awt.*;



/*

<applet code="FlowLayoutDemo" width=250 height=200>

</applet>

*/

public class FlowLayoutDemo extends Applet

implements ItemListener {

JAVA

MCA-III Page 156

String msg = "";



// set left-aligned flow layout

setLayout(new FlowLayout(FlowLayout.LEFT));





add(Win98);

add(winNT);

add(solaris);

add(mac);

// register to receive item events





JAVA

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}

// Repaint when status of a check box changes.


repaint();

}

// Display current state of the checkboxes.


msg = "Current state: ";


msg = " Windows 98: " + Win98.getState();


msg = " Windows NT: " + winNT.getState();


msg = " Solaris: " + solaris.getState();


msg = " Mac: " + mac.getState();


}

}

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10. // Demonstrate GridLayout

import java.awt.*;


/*

<applet code="GridLayoutDemo" width=300 height=200>

</applet>

*/

public class GridLayoutDemo extends Applet {

static final int n = 4;


setLayout(new GridLayout(n, n));

setFont(new Font("SansSerif", Font.BOLD, 24));

for(int i = 0; i < n; i++) {

for(int j = 0; j < n; j++) {

int k = i * n + j;

if(k > 0)

add(new Button("" + k));

}

}

JAVA

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}

}

11. // Demonstrate BorderLayout with insets.

import java.awt.*;


import java.util.*;

/*

<applet code="InsetsDemo" width=400 height=200>

</applet>

*/

public class InsetsDemo extends Applet {


// set background color so insets can be easily seen

setBackground(Color.cyan);


add(new Button("This is across the top."),

BorderLayout.NORTH);

add(new Label("The footer message might go here."),

BorderLayout.SOUTH);

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MCA-III Page 160

add(new Button("Right"), BorderLayout.EAST);

add(new Button("Left"), BorderLayout.WEST);

String msg = "The reasonable man adapts " +

"himself to the world;\n" +

"the unreasonable one persists in " +

"trying to adapt the world to himself.\n" +

"Therefore all progress depends " +

"on the unreasonable man.\n\n" +

" - George Bernard Shaw\n\n";

add(new TextArea(msg), BorderLayout.CENTER);

}

// add insets

public Insets getInsets() {

return new Insets(10, 10, 10, 10);

}

}

12. // Demonstrate Lists.

import java.awt.*;


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MCA-III Page 161


/*

<applet code="ListDemo" width=300 height=180>

</applet>

*/

public class ListDemo extends Applet implements ActionListener {

List os, browser;

String msg = "";


os = new List(4, true);

browser = new List(4, false);

// add items to os list

os.add("Windows 98");

os.add("Windows NT");

os.add("Solaris");

os.add("MacOS");

// add items to browser list

browser.add("Netscape 1.1");

JAVA

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browser.add("Lynx 2.4");

browser.select(1);

// add lists to window

add(os);

add(browser);


os.addActionListener(this);

browser.addActionListener(this);

}


JAVA

MCA-III Page 163

repaint();

}

// Display current selections.


int idx[];

msg = "Current OS: ";

idx = os.getSelectedIndexes();

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

msg += os.getItem(idx[i]) + " ";


msg = "Current Browser: ";

msg += browser.getSelectedItem();


}

}

13. import java.applet.Applet;

import java.awt.*;


public class MenuDemo extends Applet {

Frame f;

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MCA-III Page 164

/* <applet code=MenuDemo width=300 height=100>

</applet>*/





setSize(new Dimension(width, height));


f.setVisible(true);

}


f.setVisible(true);

}



}

}

14. // Illustrate menus.

JAVA

MCA-III Page 165

import java.awt.*;



/*

<applet code="MenuDemo" width=250 height=250>

</applet>

*/

// Create a subclass of Frame

class MenuFrame extends Frame {

String msg = "";

CheckboxMenuItem debug, test;

MenuFrame(String title) {

super(title);

// create menu bar and add it to frame

MenuBar mbar = new MenuBar();

setMenuBar(mbar);

// create the menu items

Menu file = new Menu("File");

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MCA-III Page 166

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 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 sub = new Menu("Special");

MenuItem item10, item11, item12;

sub.add(item10 = new MenuItem("First"));

sub.add(item11 = new MenuItem("Second"));

sub.add(item12 = new MenuItem("Third"));

edit.add(sub);

// these are checkable menu items

JAVA

MCA-III Page 167

debug = new CheckboxMenuItem("Debug");

edit.add(debug);

test = new CheckboxMenuItem("Testing");

edit.add(test);

mbar.add(edit);

// create an object to handle action and item events

MyMenuHandler handler = new MyMenuHandler(this);

// register it to receive those events

item1.addActionListener(handler);












JAVA

MCA-III Page 168

debug.addItemListener(handler);

test.addItemListener(handler);

// create an object to handle window events

MyWindowAdapter adapter = new MyWindowAdapter(this);


addWindowListener(adapter);

}



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);

}

JAVA

MCA-III Page 169

}

class MyWindowAdapter extends WindowAdapter {

MenuFrame menuFrame;

public MyWindowAdapter(MenuFrame menuFrame) {

this.menuFrame = menuFrame;

}

public void windowClosing(WindowEvent we) {

menuFrame.setVisible(false);

}

}

class MyMenuHandler implements ActionListener, ItemListener {


public MyMenuHandler(MenuFrame menuFrame) {


}

// Handle action events


String msg = "You selected ";

String arg = (String)ae.getActionCommand();

if(arg.equals("New..."))

JAVA

MCA-III Page 170

msg += "New.";

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"))

JAVA

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msg += "Debug.";

else if(arg.equals("Testing"))

msg += "Testing.";

menuFrame.msg = msg;

menuFrame.repaint();

}

// Handle item events



}

}

/*


public class MenuDemo extends Applet {

Frame f;





setSize(new Dimension(width, height));

JAVA

MCA-III Page 172


f.setVisible(true);

}


f.setVisible(true);

}



}

}

*/

13. // Demonstrate Dialog box.

import java.awt.*;



/*

<applet code="DialogDemo" width=250 height=250>

</applet>

*/

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MCA-III Page 173

// Create a subclass of Dialog.

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);

}


dispose();

}


g.drawString("This is in the dialog box", 10, 70);

}

}

JAVA

MCA-III Page 174

// Create a subclass of Frame.


String msg = "";



super(title);



setMenuBar(mbar);







file.add(new MenuItem("-"));


mbar.add(file);

JAVA

MCA-III Page 175

Menu edit = new Menu("Edit");


edit.add(item5 = new MenuItem("Cut"));

edit.add(item6 = new MenuItem("Copy"));

edit.add(item7 = new MenuItem("Paste"));

edit.add(new MenuItem("-"));

Menu sub = new Menu("Special", true);


sub.add(item8 = new MenuItem("First"));

sub.add(item9 = new MenuItem("Second"));

sub.add(item10 = new MenuItem("Third"));

edit.add(sub);



edit.add(debug);


edit.add(test);

mbar.add(edit);

JAVA

MCA-III Page 176




















JAVA

MCA-III Page 177

}





else


if(test.getState())


else


}

}





}


JAVA

MCA-III Page 178

menuFrame.dispose();

}

}





}





// Activate a dialog box when New is selected.

if(arg.equals("New...")) {

msg += "New.";

SampleDialog d = new

SampleDialog(menuFrame, "New Dialog Box");

d.setVisible(true);

}

// Try defining other dialog boxes for these options.

else if(arg.equals("Open..."))

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MCA-III Page 179

msg += "Open.";


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.";


msg += "Debug.";


JAVA

MCA-III Page 180

msg += "Testing.";



}



}

}

/*


public class DialogDemo extends Applet {

Frame f;





setSize(width, height);


JAVA

MCA-III Page 181

f.setVisible(true);

}


f.setVisible(true);

}



}

}

*/

14. /* Demonstrate File Dialog box.

This is an application, not an applet.

*/

import java.awt.*;


// Create a subclass of Frame

class SampleFrame extends Frame {

SampleFrame(String title) {

JAVA

MCA-III Page 182

super(title);





}

}


SampleFrame sampleFrame;

public MyWindowAdapter(SampleFrame sampleFrame) {

this.sampleFrame = sampleFrame;

}


sampleFrame.setVisible(false);

}

}


class FileDialogDemo {


Frame f = new SampleFrame("File Dialog Demo");

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f.setVisible(true);

f.setSize(100, 100);

FileDialog fd = new FileDialog(f, "File Dialog");

fd.setVisible(true);

}

}

15. // Demonstrate scroll bars.

import java.awt.*;



/*

<applet code="SBDemo" width=300 height=200>

</applet>

*/

public class SBDemo extends Applet

implements AdjustmentListener, MouseMotionListener {

String msg = "";

Scrollbar vertSB, horzSB;


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MCA-III Page 184



vertSB = new Scrollbar(Scrollbar.VERTICAL,

0, 1, 0, height);

horzSB = new Scrollbar(Scrollbar.HORIZONTAL,

0, 1, 0, width);

add(vertSB);

add(horzSB);

// register to receive adjustment events

vertSB.addAdjustmentListener(this);

horzSB.addAdjustmentListener(this);

addMouseMotionListener(this);

}

public void adjustmentValueChanged(AdjustmentEvent ae) {

repaint();

}

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MCA-III Page 185

// Update scroll bars to reflect mouse dragging.

public void mouseDragged(MouseEvent me) {

int x = me.getX();

int y = me.getY();

vertSB.setValue(y);

horzSB.setValue(x);

repaint();

}

// Necessary for MouseMotionListener

public void mouseMoved(MouseEvent me) {

}

// Display current value of scroll bars.


msg = "Vertical: " + vertSB.getValue();

msg += ", Horizontal: " + horzSB.getValue();


// show current mouse drag position

g.drawString("*", horzSB.getValue(),

vertSB.getValue());

JAVA

MCA-III Page 186

}

}

16. // Demonstrate TextArea.

import java.awt.*;


/*

<applet code="TextAreaDemo" width=300 height=250>

</applet>

*/

public class TextAreaDemo extends Applet {


String val = "There are two ways of constructing " +

"a software design.\n" +

"One way is to make it so simple\n" +

"that there are obviously no deficiencies.\n" +

"And the other way is to make it so complicated\n" +

"that there are no obvious deficiencies.\n\n" +

" -C.A.R. Hoare\n\n" +

"There's an old story about the person who wished\n" +

"his computer were as easy to use as his telephone.\n" +

"That wish has come true,\n" +

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"since I no longer know how to use my telephone.\n\n" +

" -Bjarne Stroustrup, AT&T, (inventor of C++)";

TextArea text = new TextArea(val, 10, 30);

add(text);

}

}

17. // Demonstrate text field.

import java.awt.*;



/*

<applet code="TextFieldDemo" width=380 height=150>

</applet>

*/

public class TextFieldDemo extends Applet

implements ActionListener {

TextField name, pass;


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MCA-III Page 188

Label namep = new Label("Name: ", Label.RIGHT);

Label passp = new Label("Password: ", Label.RIGHT);

name = new TextField(12);

pass = new TextField(8);

pass.setEchoChar('?');

add(namep);

add(name);

add(passp);

add(pass);


name.addActionListener(this);

pass.addActionListener(this);

}

// User pressed Enter.


repaint();

}


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MCA-III Page 189

g.drawString("Name: " + name.getText(), 6, 60);

g.drawString("Selected text in name: "

+ name.getSelectedText(), 6, 80);

g.drawString("Password: " + pass.getText(), 6, 100);

}

}

18. // Demonstrate text field.

import java.awt.*;



/*

<applet code="TextFieldDemo1" width=380 height=150>

</applet>

*/

class SampleFrame extends Frame {

SampleFrame(String title) {

super(title);





JAVA

MCA-III Page 190

}

}


SampleFrame sampleFrame;

public MyWindowAdapter(SampleFrame sampleFrame) {

this.sampleFrame = sampleFrame;

}


sampleFrame.setVisible(false);

}

}

public class TextFieldDemo1 extends Applet


TextField name, pass;

Button b1;

String s1;

Frame f;


JAVA

MCA-III Page 191

Label namep = new Label("Name: ", Label.RIGHT);

Label passp = new Label("Password: ", Label.RIGHT);

name = new TextField(12);

pass = new TextField(8);

pass.setEchoChar('?');

b1=new Button("ok");

add(namep);

add(name);

add(passp);

add(pass);

add(b1);


name.addActionListener(this);

pass.addActionListener(this);

b1.addActionListener(this);

}

// User pressed Enter.


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MCA-III Page 192

repaint();

String s=ae.getActionCommand();

if(s.equals("ok"))

f=new SampleFrame("button press");

f.setSize(200,200);

f.setVisible(true);

}


g.drawString("Name: " + name.getText(), 6, 60);

g.drawString("Selected text in name: " +

name.getSelectedText(), 6, 80);

g.drawString("Password: " + pass.getText(), 6, 100);

}

}

19. import java.awt.*;



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MCA-III Page 193

// Create a subclass of Dialog.

class SampleDialog1 extends Dialog implements ActionListener {

SampleDialog1(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);

}


dispose();

}


g.drawString("This is in the dialog box", 10, 70);

}

}

JAVA

MCA-III Page 194


String msg = "";



super(title);



setMenuBar(mbar);







file.add(new MenuItem("-"));


mbar.add(file);

JAVA

MCA-III Page 195



file.add(debug);


file.add(test);











JAVA

MCA-III Page 196




}





else


if(test.getState())


else


}

}




JAVA

MCA-III Page 197


}


menuFrame.dispose();

}

}





}





// Activate a dialog box when New is selected.

if(arg.equals("New...")) {

msg += "New.";

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MCA-III Page 198

SampleDialog1 d = new SampleDialog1(menuFrame, "New

Dialog Box");

d.setVisible(true);

System.out.println("Hello World!");

}

// Try defining other dialog boxes for these options.

else if(arg.equals("Open...")){

msg += "Open.";

FileDialog d = new

FileDialog(menuFrame, "open Dialog

Box",FileDialog.LOAD);

d.setVisible(true);

}

else if(arg.equals("Quit"))

msg += "Quite.";


msg += "Close.";


msg += "Debug.";


msg += "Testing.";

JAVA

MCA-III Page 199



}



}

}

class f1

{

public static void main(String[] args)

{

Frame f;


f.setSize(300, 300);

f.setVisible(true);

}

}

JAVA

MCA-III Page 200

SWINGS PROGRAMS




/*

<applet code="JButtonDemo" width=250 height=300>

</applet>

*/

public class JButtonDemo extends JApplet


JTextField jtf;


// Get content pane

Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());

// Add buttons to content pane

JAVA

MCA-III Page 201

ImageIcon france = new ImageIcon("france.gif");

JButton jb = new JButton(france);

jb.setActionCommand("France");

jb.addActionListener(this);

contentPane.add(jb);

ImageIcon germany = new ImageIcon("germany.gif");

jb = new JButton(germany);

jb.setActionCommand("Germany");



ImageIcon italy = new ImageIcon("italy.gif");

jb = new JButton(italy);

jb.setActionCommand("Italy");



ImageIcon japan = new ImageIcon("japan.gif");

jb = new JButton(japan);

jb.setActionCommand("Japan");


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MCA-III Page 202


// Add text field to content pane

jtf = new JTextField(15);

contentPane.add(jtf);

}


jtf.setText(ae.getActionCommand());

}

}




/*

<applet code="JCheckBoxDemo" width=400 height=50>

</applet>

*/

public class JCheckBoxDemo extends JApplet


JTextField jtf;

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MCA-III Page 203


// Get content pane



// Create icons

ImageIcon normal = new ImageIcon("normal.gif");

ImageIcon rollover = new ImageIcon("rollover.gif");

ImageIcon selected = new ImageIcon("selected.gif");

// Add check boxes to the content pane

JCheckBox cb = new JCheckBox("C", normal);

cb.setRolloverIcon(rollover);

cb.setSelectedIcon(selected);

cb.addItemListener(this);

contentPane.add(cb);

cb = new JCheckBox("C++", normal);



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MCA-III Page 204



cb = new JCheckBox("Java", normal);





cb = new JCheckBox("Perl", normal);





// Add text field to the content pane



}


JCheckBox cb = (JCheckBox)ie.getItem();

JAVA

MCA-III Page 205

jtf.setText(cb.getText());

}

}




/*

<applet code="JComboBoxDemo" width=300 height=100>

</applet>

*/

public class JComboBoxDemo extends JApplet


JLabel jl;

ImageIcon france, germany, italy, japan;


// Get content pane



JAVA

MCA-III Page 206

// Create a combo box and add it

// to the panel

JComboBox jc = new JComboBox();

jc.addItem("France");

jc.addItem("Germany");

jc.addItem("Italy");

jc.addItem("Japan");

jc.addItemListener(this);

contentPane.add(jc);

// Create label

jl = new JLabel(new ImageIcon("france.gif"));

contentPane.add(jl);

}


String s = (String)ie.getItem();

jl.setIcon(new ImageIcon(s + ".gif"));

}

}



JAVA

MCA-III Page 207

/*

<applet code="JLabelDemo" width=250 height=150>

</applet>

*/

public class JLabelDemo extends JApplet {


// Get content pane


// Create an icon

ImageIcon ii = new ImageIcon("france.gif");

// Create a label

JLabel jl = new JLabel("France", ii, JLabel.CENTER);

// Add label to the content pane

contentPane.add(jl);

}

}


JAVA

MCA-III Page 208



/*

<applet code="JRadioButtonDemo" width=300 height=50>

</applet>

*/

public class JRadioButtonDemo extends JApplet


JTextField tf;


// Get content pane



// Add radio buttons to content pane

JRadioButton b1 = new JRadioButton("A");


contentPane.add(b1);

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MCA-III Page 209

JRadioButton b2 = new JRadioButton("B");



JRadioButton b3 = new JRadioButton("C");



// Define a button group

ButtonGroup bg = new ButtonGroup();

bg.add(b1);

bg.add(b2);

bg.add(b3);

// Create a text field and add it

// to the content pane

tf = new JTextField(5);

contentPane.add(tf);

}


tf.setText(ae.getActionCommand());

JAVA

MCA-III Page 210

}

}



/*

<applet code="JScrollPaneDemo" width=300 height=250>

</applet>

*/

public class JScrollPaneDemo extends JApplet {


// Get content pane


contentPane.setLayout(new BorderLayout());

// Add 400 buttons to a panel

JPanel jp = new JPanel();

jp.setLayout(new GridLayout(20, 20));

int b = 0;

for(int i = 0; i < 20; i++) {

JAVA

MCA-III Page 211

for(int j = 0; j < 20; j++) {

jp.add(new JButton("Button " + b));

++b;

}

}

// Add panel to a scroll pane

int v =

ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED;

int h =

ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED;

JScrollPane jsp = new JScrollPane(jp, v, h);

// Add scroll pane to the content pane

contentPane.add(jsp, BorderLayout.CENTER);

}

}

7. import javax.swing.*;

/*

<applet code="JTabbedPaneDemo" width=400 height=100>

</applet>

*/

JAVA

MCA-III Page 212

public class JTabbedPaneDemo extends JApplet {


JTabbedPane jtp = new JTabbedPane();

jtp.addTab("Cities", new CitiesPanel());

jtp.addTab("Colors", new ColorsPanel());

jtp.addTab("Flavors", new FlavorsPanel());

getContentPane().add(jtp);

}

}

class CitiesPanel extends JPanel {

public CitiesPanel() {

JButton b1 = new JButton("New York");

add(b1);

JButton b2 = new JButton("London");

add(b2);

JButton b3 = new JButton("Hong Kong");

JAVA

MCA-III Page 213

add(b3);

JButton b4 = new JButton("Tokyo");

add(b4);

}

}

class ColorsPanel extends JPanel {

public ColorsPanel() {

JCheckBox cb1 = new JCheckBox("Red");

add(cb1);

JCheckBox cb2 = new JCheckBox("Green");

add(cb2);

JCheckBox cb3 = new JCheckBox("Blue");

add(cb3);

}

}

class FlavorsPanel extends JPanel {

public FlavorsPanel() {

JAVA

MCA-III Page 214

JComboBox jcb = new JComboBox();

jcb.addItem("Vanilla");

jcb.addItem("Chocolate");

jcb.addItem("Strawberry");

add(jcb);

}

}



/*

<applet code="JTableDemo" width=400 height=200>

</applet>

*/

public class JTableDemo extends JApplet {


// Get content pane

JAVA

MCA-III Page 215


// Set layout manager


// Initialize column headings

final String[] colHeads = { "Name", "Phone", "Fax" };

// Initialize data

final Object[][] data = {

{ "Gail", "4567", "8675" },

{ "Ken", "7566", "5555" },

{ "Viviane", "5634", "5887" },

{ "Melanie", "7345", "9222" },

{ "Anne", "1237", "3333" },

{ "John", "5656", "3144" },

{ "Matt", "5672", "2176" },

{ "Claire", "6741", "4244" },

{ "Erwin", "9023", "5159" },

{ "Ellen", "1134", "5332" },

{ "Jennifer", "5689", "1212" },

{ "Ed", "9030", "1313" },

JAVA

MCA-III Page 216

{ "Helen", "6751", "1415" }

};

// Create the table

JTable table = new JTable(data, colHeads);

// Add tree to a scroll pane

int v =


int h =


JScrollPane jsp = new JScrollPane(table, v, h);



}

}



/*

<applet code="JTextFieldDemo" width=300 height=50>

</applet>

*/

JAVA

MCA-III Page 217

public class JTextFieldDemo extends JApplet {

JTextField jtf;


// Get content pane



// Add text field to content pane



}

}




import javax.swing.tree.*;

/*

<applet code="JTreeEvents" width=400 height=200>

</applet>

JAVA

MCA-III Page 218

*/

public class JTreeEvents extends JApplet {

JTree tree;

JTextField jtf;


// Get content pane




// Create top node of tree

DefaultMutableTreeNode top = new

DefaultMutableTreeNode("Options");

// Create subtree of "A"

DefaultMutableTreeNode a = new

DefaultMutableTreeNode("A");

top.add(a);

JAVA

MCA-III Page 219

DefaultMutableTreeNode a1 = new

DefaultMutableTreeNode("A1");

a.add(a1);



a.add(a2);

// Create subtree of "B"

DefaultMutableTreeNode b = new

DefaultMutableTreeNode("B");

top.add(b);

DefaultMutableTreeNode b1 = new

DefaultMutableTreeNode("B1");

b.add(b1);



b.add(b2);



b.add(b3);

// Create tree

tree = new JTree(top);

JAVA

MCA-III Page 220


int v =


int h =


JScrollPane jsp = new JScrollPane(tree, v, h);



// Add text field to applet

jtf = new JTextField("", 20);

contentPane.add(jtf, BorderLayout.SOUTH);

// Anonymous inner class to handle mouse clicks

tree.addMouseListener(new MouseAdapter() {


doMouseClicked(me);

}

});

}

void doMouseClicked(MouseEvent me) {

JAVA

MCA-III Page 221

TreePath tp = tree.getPathForLocation(me.getX(), me.getY());

if(tp != null)

jtf.setText(tp.toString());

else

jtf.setText("");

}

}




import javax.swing.tree.*;

/*

<applet code="JTreeEvents" width=400 height=200>

</applet>

*/

public class JTreeEvents1 extends JApplet {

JTree tree;

JTextField jtf;

JAVA

MCA-III Page 222


// Get content pane




// Create top node of tree

DefaultMutableTreeNode top = new

DefaultMutableTreeNode("Options");

// Create subtree of "A"

DefaultMutableTreeNode a = new

DefaultMutableTreeNode("A");

top.add(a);



a.add(a1);



a.add(a2);

JAVA

MCA-III Page 223

// Create subtree of "B"

DefaultMutableTreeNode b = new

DefaultMutableTreeNode("B");

top.add(b);



b.add(b1);



b.add(b2);



b.add(b3);

// Create tree

tree = new JTree(top);


int v =


int h =


JScrollPane jsp = new JScrollPane(tree, v, h);

JAVA

MCA-III Page 224



// Add text field to applet

jtf = new JTextField("", 20);

contentPane.add(jtf, BorderLayout.SOUTH);

// Anonymous inner class to handle mouse clicks

tree.addMouseListener(new MouseAdapter() {


doMouseClicked(me);

}

});

}

void doMouseClicked(MouseEvent me) {

TreePath tp = tree.getPathForLocation(me.getX(), me.getY());

if(tp != null)

jtf.setText(tp.toString());

else

jtf.setText("");

}

JAVA

MCA-III Page 225

}

NETWORKING PROGRAMS

1. //Demonstrate Sockets.

import java.net.*;

import java.io.*;

class a {

public static void main(String args[]) throws Exception {

Socket s = new Socket("localhost", 777);

InputStream in = s.getInputStream();


InputStreamReader(in));

OutputStream out = s.getOutputStream();

String str;

while ((str=br.readLine()) != null) {

System.out.print("fro ser"+str);

}

br.close();

JAVA

MCA-III Page 226

s.close();

}

}

2. // Demonstrate InetAddress.

import java.net.*;

class InetAddressTest

{

public static void main(String args[]) throws

UnknownHostException {

InetAddress Address = InetAddress.getLocalHost();

System.out.println(Address);

Address = InetAddress.getByName("starwave.com");

System.out.println(Address);

InetAddress SW[] =

InetAddress.getAllByName("www.nba.com");

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

System.out.println(SW[i]);

}

}

3. // Demonstrate URL.

import java.net.*;

class patrickURL {

JAVA

MCA-III Page 227

public static void main(String args[]) throws

MalformedURLException {

URL hp = new

URL("http://www.starwave.com/people/naughton/");

System.out.println("Protocol: " + hp.getProtocol());

System.out.println("Port: " + hp.getPort());

System.out.println("Host: " + hp.getHost());

System.out.println("File: " + hp.getFile());

System.out.println("Ext:" + hp.toExternalForm());

}

}


import java.net.*;

import java.io.*;

class ser {


ServerSocket ss = new ServerSocket(777);

Socket s=ss.accept();

System.out.print("connection established");

JAVA

MCA-III Page 228


PrintStream ps=new PrintStream(out);

String str = "hello client" ;

ps.println(str);

ps.println("bye");

ps.close();

s.close();

}

}

5. // Demonstrate URLConnection.

import java.net.*;

import java.io.*;

import java.util.Date;

class UCDemo

{


int c;

URL hp = new

URL("http://www.starwave.com/people/naughton/");

URLConnection hpCon = hp.openConnection();

JAVA

MCA-III Page 229

System.out.println("Date: " + new Date(hpCon.getDate()));

System.out.println("Content-Type: " +

hpCon.getContentType());

System.out.println("Expires: " + hpCon.getExpiration());

System.out.println("Last-Modified: " +

new Date(hpCon.getLastModified()));

int len = hpCon.getContentLength();

System.out.println("Content-Length: " + len);

if (len > 0) {

System.out.println("=== Content ===");

InputStream input = hpCon.getInputStream();

int i = len;

while (((c = input.read()) != -1) && (--i > 0)) {

System.out.print((char) c);

}

input.close();

} else {

System.out.println("No Content Available");

}

}

}


JAVA

MCA-III Page 230

import java.net.*;

import java.io.*;

class Whois {


int c;

Socket s = new Socket("internic.net", 43);

InputStream in = s.getInputStream();


String str = (args.length == 0 ? "starwave-dom" : args[0]) +

"\n";

byte buf[] = str.getBytes();

out.write(buf);

while ((c = in.read()) != -1) {

System.out.print((char) c);

}

s.close();

}

}

7. // Demonstrate Datagrams.

import java.net.*;

JAVA

MCA-III Page 231

class WriteServer {

public static int serverPort = 666;

public static int clientPort = 999;

public static int buffer_size = 1024;

public static DatagramSocket ds;

public static byte buffer[] = new byte[buffer_size];

public static void TheServer() throws Exception {

int pos=0;

while (true) {

int c = System.in.read();

switch (c) {

case -1:

System.out.println("Server Quits.");

return;

case '\r':

break;

case '\n':

ds.send(new DatagramPacket(buffer,pos,

InetAddress.getLocalHost(),clientPort));

pos=0;

break;

JAVA

MCA-III Page 232

default:

buffer[pos++] = (byte) c;

}

}

}

public static void TheClient() throws Exception {

while(true) {

DatagramPacket p = new DatagramPacket(buffer,

buffer.length);

ds.receive(p);

System.out.println(new String(p.getData(), 0,

p.getLength()));

}

}


if(args.length == 1) {

ds = new DatagramSocket(serverPort);

TheServer();

} else {

ds = new DatagramSocket(clientPort);

TheClient();

JAVA

MCA-III Page 233

}

}

}

Documents

Java - A Helpful Hand