Java Lab Final

1. To simply run a java program.

class Example

{

public static void main(String args[])

{

System.out.println("This is a simple Java program.");

}

}

Output:

2. 2.1 a one dimensional array declaration

class Array {


{

int month_days[];

month_days = new int[12];

month_days[0] = 31;

month_days[1] = 28;

month_days[2] = 31;

month_days[3] = 30;

month_days[4] = 31;

month_days[5] = 30;

month_days[6] = 31;

month_days[7] = 31;

month_days[8] = 30;

month_days[9] = 31;

month_days[10] = 30;

month_days[11] = 31;

System.out.println("April has " + month_days[3] + " days.");

}

}

Output:

2.2 one dimensional array declaration

class AutoArray {public static void main(String args[]) {int month_days[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31,};System.out.println("April has " + month_days[3] + " days.");}}

Output:

3. Demonstrate a two-dimensional array.

class TwoDArray

{


{

int twoD[][]= new int[4][5];

int i, j, k = 0;

for(i=0; i<4; i++)

for(j=0; j<5; j++)

{

twoD[i][j] = k;

k++;

}

for(i=0; i<4; i++) {

for(j=0; j<5; j++)

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

System.out.println();

}

}

}

Output:

4. WAP for creating a class & its object./* WAP that uses the Box class. Call this file BoxDemo.java*/class Box {double width;double height;double depth;}class BoxDemo // This class declares an object of type Box. {public static void main(String args[]) {Box mybox = new Box();double vol; // assign values to mybox's instance variablesmybox.width = 10;mybox.height = 20;mybox.depth = 15; // compute volume of boxvol = mybox.width * mybox.height * mybox.depth; // compute volume of boxSystem.out.println("Volume is " + vol);}}

Output:

5. /* A code to display a call for constructor*/class Box {double width;double height;double depth;Box() // This is the constructor for Box. {System.out.println("Constructing Box");width = 10;height = 10;depth = 10; }double volume() // compute and return volume {return width * height * depth; }}class BoxDemo6 {public static void main(String args[]) {Box mybox1 = new Box(); // declare, allocate, and initialize Box objectsdouble vol;vol = mybox1.volume(); // get volume of first boxSystem.out.println("Volume is " + vol);}}

Output:

• 6. // Demonstrate method overloading.Test( ) is overloaded two times. The first version takes no parameters, the second takes one integer parameter.

class OverloadDemo {void test() {System.out.println("No parameters");}void test(int a) // Overload test for one integer parameter. {System.out.println("a: " + a);}}class Overload {public static void main(String args[]) {OverloadDemo ob = new OverloadDemo();double result;// call all versions of test()ob.test();ob.test(10);}}

Output:

7. WAP to show MethodOverriding

class A { int j = 1; int f( ) { return j; }}class B extends A { int j = 2; int f( ) { return j; }}class MethodOverriding { public static void main(String args[]) { B b = new B(); System.out.println(b.j); // refers to B.j prints 2 System.out.println(b.f()); // refers to B.f prints 2 A a = (A) b; System.out.println(a.j); // now refers to a.j prints 1 System.out.println(a.f()); // overridden method still refers to B.f() prints 2 ! } }

Output:

8. /*WAP to show Inheritance*/

/* Single Inhetitance To Find Area Of Rectangle */class Dimensions{int length;int breadth;}

class Rectangle extends Dimensions{int a;void area(){a = length * breadth;}

}

class AreaInheritance{public static void main(String args[]){Rectangle Rect = new Rectangle();Rect.length = 7;Rect.breadth = 16;Rect.area();System.out.println("The Area of rectangle of length "+Rect.length+" and breadth "+Rect.breadth+" is "+Rect.a);}}

Output:

9. wap to show Multilevel Inheritance

class A{ int i=10,j=20; void xyz() { System.out.println(i+j); } void lmn() { System.out.println("lmn"); }}class B extends A{ int k=40,l=45; void abc() { System.out.println(i+j+k); lmn(); }}class C extends B{}class MultilevelInherit{ public static void main(String args[]) { C a1= new C(); a1.abc(); }}

Output:

10. WAP to show an Interface

interface Area

{

final static float pi=3.14F;

float compute (float x, float y);

}

class Rectangle implements Area

{

public float compute(float x, float y)

{

return(x*y);

}

}

class Circle implements Area

{

public float compute (float x, float y)

{

return (pi*x*x);

}

}

class InterfaceTest

{


{

Rectangle rect = new Rectangle();

Circle cir = new Circle();

Area area;

area = rect;

System.out.println("Area of Rectangle ="+area.compute(10,20));

area = cir;

System.out.println("Area of Circle ="+area.compute(10,0));

}

}

Output

11. WAP to implement a package

Step 1: Create a package

package FirstPack;

public class Test

{

public void view()

{

System.out.println("I am from Package");

}

}

Step 2. Save this package by creating a new folder by the name of “FirstPack” as package name and save the code as Test.java in notepad as D:\Java\bin\FirstPack\Test.java. This will create a new directory to store the package.

Step3. Create another code that imports the file stored in the package “FirstPack” using import statements as follows:

import FirstPack.Test;

public class MainPack

{


{

Test ob =new Test();

ob.view();

}

}

Step 4. Save it as MainPack.java

Step 5. GOTO cmd prompt and type the following command :

D:\Java\bin>javac FirstPack\Test.java

Test.class file will be created. After wards run the following command for importing the package into the main class “MainPack”

D:\Java\bin>javac MainPack.java

D:\Java\bin>java MainPack

Output:

12. WAP to create a simple thread

public class Threads{

public static void main(String[] args){

Thread th = new Thread();

System.out.println("Numbers are printing line by line after 5 seconds : ");

try{

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

{

System.out.println(i);

th.sleep(5000);

}

}

catch(InterruptedException e){

System.out.println("Thread interrupted!");

e.printStackTrace();

}

}

}

Output:

13. WAP to demonstrate 3 threads using the thread class.

import java.io.*;

class A extends Thread

{

public void run()

{

for (int i=1;i<5;i++)

{

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

}

System.out.println("Exit from A");

}

}

class B extends Thread

{

public void run()

{

for (int j=1;j<5;j++)

{

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

}

System.out.println("Exit from B");

}

}

class C extends Thread

{

public void run()

{

for (int k=1;k<5;k++)

{

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

}

System.out.println("Exit from C");

}

}

class ThreadExample

{


{

new A().start();

new B().start();

new C().start();

}

}

OutPut:

14. WAP to show Multithreading

class NewThread implements Runnable

{

Thread t;

NewThread()

{

t=new Thread(this,"Demo Thread");

System.out.println("Child Thread :"+t);

t.start();

}

public void run()

{

try{

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

{

System.out.println("Child Thread"+i);

Thread.sleep(500);

}

}

catch(InterruptedException e)

{

System.out.println("Child interrupted");

}

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

}

}

class ThreadDemo

{

public static void main(String arg[])

{

try{

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

{

System.out.println("main Thread"+i);

Thread.sleep(1000);

}

}

catch(InterruptedException e)

{

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

}

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

}

}

Output:

15. WAP to show Exception Handling using finally

import java.lang.Exception;

class MyException extends Exception

{

MyException (String message)

{

super (message);

}

}

class TestmyException

{


{

int x=5, y=1000;

try

{

float z= (float) x/ (float) y;

if (z<0.01)

{

throw new MyException("Number is too small");

}

}

catch (MyException e)

{

System.out.println("Caught my exception");

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

}

finally

{

System.out.println("I am always here");

}

}

}

Output:

16.1 WAP to construct one String from another.

class MakeString

{


{

char c[] = {'J','A','V','A'};

String s1= new String(c);

String s2= new String(s1);

System.out.println(s1);

System.out.println(s2);

}

}

16.2 WAP for a String Comparison:

class StringEqualsDemo

{


{

String s1 = "Hello";


String s3 = "Good-bye";


System.out.println(s1+"equals"+s2+"->"+s1.equals(s2));



System.out.println(s1+"equalsIgnoreCase"+s4+"->"+s1.equalsIgnoreCase(s4));

}

}

Output:

16.3 wap to to search inside of a String using various index methods

class IndexofDemo

{

public static void main (String args[])

{

String s=("Now is the time for all good men"+"for come out to aid the country");

System.out.println(s);

System.out.println("indexOf(t)=" +s.indexOf('t'));

System.out.println("lastIndexOf(t)=" +s.lastIndexOf('t'));

System.out.println("indexOf(the)=" +s.indexOf("sthe"));

System.out.println("lastIndexOf(the)=" +s.lastIndexOf("the"));

System.out.println("indexOf(t,10)="+s.indexOf('t', 10));

System.out.println("lastIndexOf(t,60)="+s.lastIndexOf('t', 60));

System.out.println("indexOf(the,10)="+s.indexOf("the", 10));

System.out.println("lastIndexOf(the,60)="+s.lastIndexOf("the", 60));

}

}

Ouput:

17. WAP to write and into a file in Java using I/O.

To write into a file……..

import java.io.*;

public class IOwrite

{

// Main method

public static void main (String args[])

{

// Stream to write file

FileOutputStream fout;

try

{

// Open an output stream

fout = new FileOutputStream ("myfile.txt");

// Print a line of text

new PrintStream(fout).println ("hello world!");

// Close our output stream

fout.close();

}

// Catches any error conditions

catch (IOException e)

{

System.err.println ("Unable to write to file");

System.exit(-1);

}

}

}

To read from a file

We create a FileInputStream object, read the text, and display it to the user.

import java.io.*;

public class IOread{

// Main methodpublic static void main (String args[]){

// Stream to read fileFileInputStream fin;

try{ // Open an input stream fin = new FileInputStream ("myfile.txt");

// Read a line of text System.out.println( new DataInputStream(fin).readLine() );

// Close our input stream fin.close();}// Catches any error conditionscatch (IOException e){

System.err.println ("Unable to read from file");System.exit(-1);

}}

}

Output:

18. WAP to show networking using Client-Server Socket programming in java.

18.1 write a Code to create a Server socket

import java.io.*;

import java.net.*;

import java.net.Socket;

class TCPServer

{

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

{

String clientSentence;

String capitalizedSentence;

ServerSocket welcomeSocket = new ServerSocket(6789);

while(true)

{

Socket connectionSocket = welcomeSocket.accept();

BufferedReader inFromClient =

new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));

DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());

clientSentence = inFromClient.readLine();

System.out.println("Received: " + clientSentence);

capitalizedSentence = clientSentence.toUpperCase() + '\n';

outToClient.writeBytes(capitalizedSentence);

}

}

}

Output for Server socket:

18.2 Write a Code to create a Client Socket:

import java.io.*;

import java.net.*;

import java.net.Socket;

class TCPClient

{

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

{

String sentence;

String modifiedSentence;

BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));

Socket clientSocket = new Socket("localhost", 6789);

DataOutputStream outToServer = new DataOutputStream

(clientSocket.getOutputStream());

BufferedReader inFromServer = new BufferedReader(new

InputStreamReader(clientSocket.getInputStream()));

sentence = inFromUser.readLine();

outToServer.writeBytes(sentence + '\n');

modifiedSentence = inFromServer.readLine();

System.out.println("FROM SERVER: " + modifiedSentence);

clientSocket.close();

}

}

Output for Client Socket:

Output for Networking Between Client and Server Socket.

19. To create a simple Applet

import java.awt.*;

import java.applet.Applet;

public class Applet1 extends Applet

{

public void paint(Graphics g)

{

g.drawString("Hello",30,30);

g.drawString("I am smart",40,40);

g.drawString("I am good",50,50);

g.drawString("I am a good Dancer",60,60);

g.drawString("Have fun n enjoy this class",70,70);

g.drawString("God bless u all",80,80);

}

}

/*

<applet code= "Applet1.class" width = 500 height = 500>

</applet>

*/

Output:

Run file as

C:\java\bin> javac Applet1.java

C:\java\bin>appletviewer Applet1.java

20. WAP to draw a rectangle and fill color into it using an Applet.

import java.awt.*;

import java.applet.*;

public class Applet2 extends Applet

{

public void paint(Graphics g)

{

g.setColor(Color.BLACK);

g.drawString("God bless u all",200,200);

g.drawRect(50,50,100,100);

g.setColor(Color.GREEN);

g.fillRect(50,50,100,100);

g.setColor(Color.RED);

g.fillOval(50,50,100,100);

}

}

/*

<applet code= "Applet2.class" width = 500 height = 500>

</applet>

*/

Output:

21.1 To create a basic window using Swing in Java

import javax.swing.JFrame;

import javax.swing.SwingUtilities;

public class Example1 extends JFrame {

public Example1() {

setTitle("Simple example");

setSize(300, 200);

setLocationRelativeTo(null);

setDefaultCloseOperation(EXIT_ON_CLOSE);

}

public static void main(String[] args) {

SwingUtilities.invokeLater(new Runnable() {

public void run() {

Example1 ex = new Example1();

ex.setVisible(true);

}

});

}

}

Output:

21.2 WAP to create a simple window and add a button to it using Swings in Java

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;


import javax.swing.JPanel;



public Example2() {

initUI();

}

public final void initUI() {

JPanel panel = new JPanel();

getContentPane().add(panel);

panel.setLayout(null);

JButton quitButton = new JButton("Quit");

quitButton.setBounds(50, 60, 80, 30);

quitButton.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent event) {

System.exit(0);

}

});

panel.add(quitButton);

setTitle("Quit button");

setSize(300, 200);



}



public void run() {



}

});

}

}

Output:

21.3 Code to add a Tooltip and add a button to a window created using Swing

import javax.swing.JButton;


import javax.swing.JPanel;



public Example3() {

initUI();

}

public final void initUI() {

JPanel panel = new JPanel();

getContentPane().add(panel);

panel.setLayout(null);

panel.setToolTipText("A Panel container");

JButton button = new JButton("Button");

button.setBounds(100, 60, 100, 30);

button.setToolTipText("A button component");

panel.add(button);

setTitle("Tooltip");

setSize(300, 200);



}



public void run() {



}

});

}

}

Output:

Java Lab Final

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