practical 21

8/7/2019 Practical 21

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6. Write a program to find an integer between 1 and 100, which has largest number ofdivisors. It should also print number of divisors. In case there are more than one such

integers, program need to print any one.class Divisors

{

public static void main(String args[])

{int maxd=0,maxc=0,oc;

for(int i=2;i


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7. Define an interface with two methods:-

a. void push(int item);b. int pop();define two classes which implement this interface:-

(i) Static stack with fixed size.(ii) Dynamic stack whose size can be extended dynamically.

Ans:

interface IntStack

{

int pop();

void push(int item);

}

class FixedStack implements IntStack

{private int stck[];

private int tos;

FixedStack(int size)

{stck=new int[size];

tos=-1;}

public void push(int item){

if(tos==stck.length-1)

{System.out.println("Stack is full");

}

else

{

stck[++tos]=item;

}

}

public int pop()

{

if(tos


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}class DynStack implements IntStack

{private int stck[];

private int tos;

DynStack(int size){

stck=new int[size];

tos=-1;

}

public void push(int item)

{

if(tos==stck.length-1)

{

int temp[]=new int[stck.length * 2];

for(int i=0;i


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{f1.push(i);

d1.push(i+2);}

System.out.println("Fixed stack");

for(i=0;i


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8. Write a program to create an applet, which displays a square of dimension 10 at the position where

a mouse click occurs.

Ans.

import java.applet.*;

import java.awt.*;import java.awt.event.*;

/*

*/

public class SquareMouse extends Applet{

int mouseX=0,mouseY=0,d=0;public void init()

{addMouseListener(new MouseAdapter()

{

public void mouseClicked(MouseEvent me)

{

mouseX=me.getX();

mouseY=me.getY();

d=10;

repaint();

}

});}

public void paint(Graphics g){

g.drawRect(mouseX,mouseY,d,d);}

}


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OUTPUT


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9. Define a class Employee. Write a program to serialize the objects of class Employee.

Ans.

import java.io.*;

public class SerializationTask{

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

try {System.out.println("\nSerializing\n");

Employee emp_ser1=new Employee(12311,"John",20000);

Employee emp_ser2=new Employee(13011,"Ram",25000);

System.out.println("Emp1 "+emp_ser1);System.out.println("Emp2 "+emp_ser2);

FileOutputStream fos= new FileOutputStream("emprec");

ObjectOutputStream oos=new ObjectOutputStream(fos);oos.writeObject(emp_ser1);oos.writeObject(emp_ser2);

oos.flush();oos.close();

}

catch(Exception e)

{ System.out.println("Exception during serialization");

System.exit(0);

}

try

{

System.out.println("\nDeserializing\n");Employee emp_dser1,emp_dser2;

FileInputStream fis= new FileInputStream("emprec");

ObjectInputStream ois=new ObjectInputStream(fis);

emp_dser1=(Employee)ois.readObject();

emp_dser2=(Employee)ois.readObject();ois.close();

System.out.println("Emp1 "+emp_dser1);System.out.println("Emp2 "+emp_dser2);

}catch(Exception e)

{

System.out.println("Exception during deserialization");System.exit(0);

}

}

}

class Employee implements Serializable

{

String s;

int i;


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double d;

public Employee(int i,String s,double d){

this.i=i;

this.s=s;

this.d=d;}

public String toString()

{

return "i=" + i +"; s="+s+"; d="+d;

}

}

OUTPUT


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10. Write to implement word count utility, which should display the count of characters, words and

lines. Input can be a disk file or data read from console.

Ans.

import java.io.*;

class lnrdemo3

{public static long numChar = 0;public static long numLine = 0;

public static long numWords = 0;private static long wordcount(String line)

{

long numWords1 = 0;

int index = 0;boolean prevWhiteSpace = true;

while(index < line.length())

{

char c = line.charAt(index++);boolean currWhiteSpace = Character.isWhitespace(c);

if(prevWhiteSpace && !currWhiteSpace){

numWords1++;

}

prevWhiteSpace = currWhiteSpace;}

return numWords1;}

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

{

int ch;String choice;

BufferedReader in = new BufferedReader(newInputStreamReader(System.in));

System.out.print("Enter 1: to Read from file or 2 from

console: ");

choice = in.readLine();ch = Integer.parseInt(choice);

System.out.println();switch (ch)

{case 1: System.out.print(" pass the file name: ");

BufferedReader ini = new BufferedReader(new

InputStreamReader(System.in));String str = ini.readLine();File file = new File(str);

FileReader f = new FileReader(file);BufferedReader brObj = new BufferedReader(f);

String line;

try{

while ((line = brObj.readLine()) != null)


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{

numChar += line.length();numWords += wordcount(line);

numLine++;}

System.out.println();System.out.println("File Name: " + str);

brObj.close();

}catch (Exception e){

brObj.close();System.out.println(e);

}

break;

case 2: BufferedReader inc = new BufferedReader(newInputStreamReader(System.in));

String line1;

System.out.println("pass the Paragragh to read");

System.out.println("enter Q/q when input is over");

try{

do

{

line1=inc.readLine();numChar += line1.length();

numWords += wordcount(line1);numLine++;

}

while (!line1.toLowerCase().equals("q"));

numChar--;numWords--;

numLine--;System.out.println();

}

catch (Exception e)

{System.out.println(e);

}break;

default:System.out.print("Entered wrong choice");}

System.out.println("Number of characters: " + numChar);

System.out.println("Number of words: " + numWords);System.out.println("Number of Lines: " + numLine);

}

}


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The Output is:


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11. Write a program to create two packages p1 and p2.

Define three classes in p1:

i. P1oneinstance variables of type int: a (no access modifier), b (private), c (protected), d (public)

ii. P1two (subclass of P1one)iii. P1three (not a subclass of P1one)

Define two classes in p2:

i. P2one (subclass of P1one)ii. P2two (not a subclass of P1one)

Demonstrate the access of four instance variables a, b, c, d of the class P1one in all of these classes.

Ans.

package p1;

public class P1one

{

int a=1;

private int b=2;

protected int c=3;

public int d=4;

public P1one()

{

System.out.println("P1one contructor");

System.out.println("a= "+a);

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

System.out.println("c= "+c);

System.out.println("d= "+d);

}

}

package p1;

class P1two extends P1one


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{

P1two()

{

System.out.println("P1two constructor");

System.out.println("a= "+a);

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


System.out.println("d= "+d);

}

}

package p1;

class P1three

{

P1three()

{

P1one p=new P1one();

System.out.println("P1three constructor");

System.out.println("a= "+p.a);

//System.out.println("b= "+p.b);

System.out.println("c= "+p.c);

System.out.println("d= "+p.d);

}

}

package p1;

public class Accessor

{


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{

P1one ob1=new P1one();

P1two ob2=new P1two();

P1three ob3=new P1three();

}

}

OUTPUT

Program

package p2;

class P2one extends p1.P1one

{

P2one()

{

System.out.println("P2one constructor");

//System.out.println("a= "+a);

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



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12. WAP for implementing TCP Client-Server program.

import java.io.*;

import java.net.*;

public class EchoServer {

/** Our server-side rendezvous socket */

protected ServerSocket sock;

/** The port number to use by default */

public final static int ECHOPORT = 8040;

/** Flag to control debugging */

protected boolean debug = true;

/** main: construct and run */

public static void main(String[] argv) {

new EchoServer(ECHOPORT).handle();

}

/** Construct an EchoServer on the given port number */

public EchoServer(int port) {

try {

sock = new ServerSocket(port);

} catch (IOException e) {

System.err.println("I/O error in setup");

System.err.println(e);

System.exit(1);

}

}

/** This handles the connections */

protected void handle( ) {


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Socket ios = null;

BufferedReader is = null;

PrintWriter os = null;

while (true) {

try {

ios = sock.accept( );

System.err.println("Accepted from " +

ios.getInetAddress().getHostName());

is = new BufferedReader(

new InputStreamReader(ios.getInputStream()));

os = new PrintWriter(new OutputStreamWriter(

ios.getOutputStream()),true);

String echoLine;

while ((echoLine=is.readLine())!=null) {

System.err.println("Read " + echoLine);

os.print(echoLine + "\r\n");

os.flush();

System.err.println("Wrote " + echoLine);

}

System.err.println("All done!");



} finally {

try {

if (is != null)

is.close( );


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if (os != null)

os.close( );

if (ios != null)

ios.close( );


System.err.println("IO Error in close");

}

}

}

}}

import java.io.*;import java.net.*;

public class EchoClientOneLine {

/** What we send across the net */

String mesg = "Hello across the net";

public static void main(String[] argv) {

if (argv.length == 0)

new EchoClientOneLine( ).converse("localhost");

else

new EchoClientOneLine( ).converse(argv[0]);

}

/** Hold one conversation across the net */

protected void converse(String hostName) {


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try {

Socket sock = new Socket(hostName, 8040); // echo server.

BufferedReader is = new BufferedReader(new

InputStreamReader(sock.getInputStream( )));

PrintWriter os = new PrintWriter(sock.getOutputStream( ), true);

os.print(mesg + "\r\n");

os.flush( );

String reply = is.readLine( );

System.out.println("Sent \"" + mesg + "\"");

System.out.println("Got \"" + reply + "\"");



}

}

}

OUTPUT


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13. WAP for implementing UDP Client-Server program.

UDP Sender

import java.io.*;

import java.net.*;

/*** This class sends the specified text as a datagram to the

* specified port of the specified host.

**/

public class UDPSend {

public static final String usage =

"Usage: java UDPSend ...\n" +

" or: java UDPSend -f ";

public static void main(String args[ ]) {

try {// Check the number of arguments

if (args.length < 3)throw new IllegalArgumentException("Wrong number of args");

// Parse the argumentsString host = args[0];

int port = Integer.parseInt(args[1]);

// Figure out the message to send.

byte[ ] message;

String msg = args[2];

for (int i = 3; i < args.length; i++) msg += " " + args[i];

// Convert the message to bytes using UTF-8 encoding

message = msg.getBytes("UTF-8");

// Get the internet address of the specified host

InetAddress address = InetAddress.getByName(host);

// Initialize a datagram packet with data and address

DatagramPacket packet = new DatagramPacket(message, message.length,

address, port);

// Create a datagram socket, send the packet through it, close it.DatagramSocket dsocket = new DatagramSocket( );

dsocket.send(packet);dsocket.close( );

}

catch (Exception e) {System.err.println(e);System.err.println(usage);

}

}}


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UDP Reciver

import java.io.*;

import java.net.*;

/**

* This program waits to receive datagrams sent to the specified port.

* When it receives one, it displays the sending host and prints the

* contents of the datagram as a string. Then it loops and waits again.

**/

public class UDPReceive {

public static final String usage = "Usage: java UDPReceive ";

public static void main(String args[ ]) {

try {

if (args.length != 1)throw new IllegalArgumentException("Wrong number of args");

// Get the port from the command line

int port = Integer.parseInt(args[0]);

// Create a socket to listen on the port.DatagramSocket dsocket = new DatagramSocket(port);

// Create a buffer to read datagrams into. If anyone sends us a

// packet containing more than will fit into this buffer, the

// excess will simply be discarded!

byte[ ] buffer = new byte[2048];

// Create a packet to receive data into the buffer

DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

// Now loop forever, waiting to receive packets and printing them.

for(;;) {

// Wait to receive a datagram

dsocket.receive(packet);

// Decode the bytes of the packet to characters, using the// UTF-8(UNICODE TRANSFORMATION FORMAT)

//encoding, and then display those characters.

String msg = new String(buffer, 0, packet.getLength( ),"UTF-8");System.out.println(packet.getAddress( ).getHostName( ) +": " + msg);

// Reset the length of the packet before reusing it.

packet.setLength(buffer.length);

}

}


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catch (Exception e) {System.err.println(e);

System.err.println(usage);}

}

}

OUTPUT


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14. Write a program to display a frame containing text area. It should be possible to format the text by

choosing its font name, style and font size. Font names should be given in a list box, font styles incheck boxes and font size in a text field.

import java.awt.*;

import java.awt.event.*;

class format extends Frame implements ItemListener

{

TextArea a1;

TextField t1;

List l1;

Checkbox c1,c2;GraphicsEnvironment g;

String f[];int i;

Panel p1,p2,p3;Label font,style,size;

format()

{

g=GraphicsEnvironment.getLocalGraphicsEnvironment();

f=g.getAvailableFontFamilyNames();

setBackground(Color.yellow);

setSize(600,600);

setTitle("Font Frame");

l1=new List();

font=new Label("FONT NAME");

size=new Label("FONT SIZE");

style=new Label("FONT STYLE");t1=new TextField(15);

a1=new TextArea(2,15);c1 = new Checkbox("Italic");

c2 = new Checkbox("Bold");for(i=0;i


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font.setBounds(10,10,100,20);

size.setBounds(270,10,100,20);

style.setBounds(10,10,250,20);

p1.setBounds(30,50,400,200);p2.setBounds(430,40,180,200);

p3.setBounds(10,210,580,400);

p1.add(l1);

p1.add(font);

p1.add(t1);

p1.add(size);

p2.add(style);

p3.add(a1);

p2.add(c1);p2.add(c2);

add(p1);

add(p2);add(p3);

setVisible(true);l1.addItemListener(this);

t1.addFocusListener(new focus(this));

c1.addItemListener(this);

c2.addItemListener(this);

}


{

format f=new format();

}

public void itemStateChanged(ItemEvent ie)

{

set();}

public void set()

{

if(c2.getState() && !c1.getState())a1.setFont(newFont(f[l1.getSelectedIndex()],Font.BOLD,Integer.parseInt(t1.getText())));

else

if(!c2.getState() && c1.getState())

a1.setFont(new

Font(f[l1.getSelectedIndex()],Font.ITALIC,Integer.parseInt(t1.getText())));

else

if(c2.getState() && c1.getState())


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a1.setFont(new Font (f[l1.getSelectedIndex()], Font.ITALIC |Font.BOLD,

Integer.parseInt(t1.getText())));else

a1.setFont(new

Font(f[l1.getSelectedIndex()],Font.PLAIN,Integer.parseInt(t1.getText())));

}}

class focus extends FocusAdapter

{

format f1;

public focus(format f)

{

f1=f;

}

public void focusLost(FocusEvent e){

String s = f1.t1.getText();for(int i=0;i


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OUTPUT


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15. Define a class to check DateFormatException. Define another class Day whichencapsulates the features of day. This class should contain following methods:-

void advance(int n) advances the date currently set by a specified number of days. Forexample, d.advance(100) changes d to a date 100 days later.

import java.text.ParseException;

import java.text.SimpleDateFormat;import java.util.Date;

import java.io.*;

import java.util.Calendar;

// This program creates a custom exception type.

class DATEFORMATEXCEPTION extends Exception

{

private int flag;

DATEFORMATEXCEPTION (int flag)

{

this.flag = flag;

}public String toString()

{

if (flag==1)return "Entered Day is Not Correct";

else if (flag == 2)

return "Entered month is Not Correct";

else

return "Entered year is Not Correct";

}

}

class ValidationExp2

{

static void compute(int day, int month, int year)throws DATEFORMATEXCEPTION

{

if (year > 3010 || year < 1900)

throw new DATEFORMATEXCEPTION(3);else if (month > 12 || month < 1)

throw new DATEFORMATEXCEPTION(2);else if ((month == 4 || month == 6 || month == 9 || month == 11) && (day > 30

|| day < 1))

throw new DATEFORMATEXCEPTION(1);else if ((month == 1 || month == 3 || month == 5 || month == 7 || month == 8 ||month == 10 || month == 12) && (day > 31 || day < 1))

throw new DATEFORMATEXCEPTION(1);

else if (month == 2)

{

if (((year % 4 != 0) && (year % 400 != 0 && year % 100 != 0)) &&

(day > 28 || day < 1))



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else if (((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0 &&year % 100 == 0)) && (day > 29 || day < 1))


}

}static void advance(Date date)throws IOException

{

String str1;

BufferedReader in = new BufferedReader(new

InputStreamReader(System.in));

System.out.print("Enter number of days to increment: ");

str1 = in.readLine();

int day = Integer.parseInt(str1);

Calendar cal = Calendar.getInstance();

cal.setTime(date);

cal.add(Calendar.DATE, day);

date = cal.getTime();System.out.println("Date :- " + date);

}

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

{

String pattern = "dd:MM:yy";

String str, str1;

SimpleDateFormat sdf = new SimpleDateFormat();

BufferedReader in = new BufferedReader(new

InputStreamReader(System.in));

System.out.print("day: ");

str1 = in.readLine();

int day = Integer.parseInt(str1);

str = str1;

System.out.print("month: ");

str1 = in.readLine();int month = Integer.parseInt(str1);

str = str + ":" + str1;

System.out.print("year: ");str1 = in.readLine();

int year = Integer.parseInt(str1);

str = str + ":" + str1;

try

{

sdf.applyPattern(pattern);


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compute(day, month, year);Date date = sdf.parse(str);

System.out.println("Date :- " + date);advance(date);

}catch (DATEFORMATEXCEPTION e)

{

System.out.println("Caught " + e);

}

catch (ParseException e)

{

System.out.println("Wrong date format");

e.printStackTrace();

}

}

}

output

C:\java>javac ValidationExp2.java

C:\java>java ValidationExp2

day: 23

month: 3

year: 2004

Date :- Tue Mar 23 00:00:00 GMT+05:30 2004

Enter number of days to increment: 100

Date :- Thu Jul 01 00:00:00 GMT+05:30 2004

C:\java>java ValidationExp2

day: 31

month: 2year: 2004

Caught Entered Day is Not Correct


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16. Define a class Result to describe the result of students. Create a subclass SportResults. Define an

interface Display which includesfollowing methods:

Display student personal detailsDisplay students' academic result

Display students' sport result

abstract class display

{public abstract void personal(String s,int r,String a);public abstract void academic(int m1,int m2,int m3);

public abstract void sportresult(String r);}

abstract class result extends display

{

public void personal(String name,int roll,String adrs){

System.out.println("Name "+name+"\nRoll no "+roll+"\nAddress "+adrs);

}

public void academic(int m10,int m12,int mg){

System.out.println("10 Marks "+m10+"\n12 Marks "+m12+"\nGraduation Marks"+mg);

}

}

class sportresult extends result{

public void sportresult(String r){

System.out.println("Result in footBall "+r);

}

}

class test{

public static void main(String a[]){

sportresult o= new sportresult();

o.personal("Sam",1,"Delhi");

o.academic(78,80,83);o.sportresult("Winner");

}}

Output :Name Sam

Roll no 1

Address Delhi 10 Marks 7812 Marks 80Graduation Marks 83 Result in footBall Winner


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17. Write a program which generates following types of exceptions. Demonstrate how theseexceptions are handled.

ArithmeticExceotionArrayIndexOutOfBoundsException

ArrayStoreException

ClassCastException

NegativeArraySizeExceptionNullPointerException

NumberFormatException

import java.io.*;

class exception

{

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

{

int ch=0;BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

System.out.print("");System.out.println(" Press 1 for Airthmetic Exception");

System.out.println(" Press 2 for Arrary Index out of Bound Exception");System.out.println(" Press 3 for Array store Exception");

System.out.println(" Press 4 for Class Cast exception");System.out.println(" Press 5 for Negative Array Size Exception");

System.out.println(" Press 6 for Null Pointer Exception");

System.out.println(" Press 7 for Number Format Exception");

System.out.println("");

while(ch!=8)

{

System.out.println("Enter your choice : ");

ch=Integer.parseInt(br.readLine());

switch(ch)

{

case 1:

{

try

{int a=0;

int b=56/a;}

catch(ArithmeticException e)

{ System.out.println("Divide By zero: "+e);}

break;

}

case 2:

{

try


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{int a[]=new int[10];

a[20]=4;}

catch(ArrayIndexOutOfBoundsException a)

{

System.out.println("Array out of bound exception: "+a);}

break;

}

case 3:

{

try

{

Object x[] = new String[3];

x[0] = new Integer(0);}

catch(ArrayStoreException a){

System.out.println("Array store exception: "+a);}

break;}

case 4:

{

try

{

Object x = new Integer(0);

System.out.println((String)x);

}

catch(ClassCastException c)

{

System.out.println("class cast exception "+c);

}

break;}

case 5:

{

try{int arr[]=new int[-6];

arr[-1]=6;

}

catch(NegativeArraySizeException n)

{

System.out.println("Negative Array Size Exception: "+n);

}


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break;}

case 6:

{

try

{throw new NullPointerException();

}

catch(NullPointerException n)

{

System.out.println("Null Pointer exception: "+n);

}

break;

}

case 7:{

try{

String s1 = "abc";int i = Integer.parseInt(s1);

}catch(NumberFormatException n)

{

System.out.println("Number format exception: "+n);

}

break;

}

}

}

}

}


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The output is:D:\practicals\Java\Demo\Exception>javac exception.java

D:\practicals\Java\Demo\Exception>java exceptionPress 1 for Airthmetic Exception

Press 2 for Arrary Index out of Bound Exception

Press 3 for Array store Exception

Press 4 for Class Cast exceptionPress 5 for Negative Array Size Exception

Press 6 for Null Pointer Exception

Press 7 for Number Format Exception

Enter your choice :

1

Divide By zero: java.lang.ArithmeticException: / by zero

Enter your choice :

2

Array out of bound exception: java.lang.ArrayIndexOutOfBoundsException: 20Enter your choice :

3Array store exception: java.lang.ArrayStoreException: java.lang.Integer

Enter your choice :4

class cast exception java.lang.ClassCastException: java.lang.Integer cannot be cast tojava.lang.String

Enter your choice :

5

Negative Array Size Exception: java.lang.NegativeArraySizeException

Enter your choice :

6

Null Pointer exception: java.lang.NullPointerException

Enter your choice :

7

Number format exception: java.lang.NumberFormatException: For input string: "abc"

Enter your choice :

8


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practical 21

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