cs2309 java lab manual2
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Ex No1: Rational Numbers
AIM To write a Java Program to develop a class for Rational numbers.
ALGORITHM:
Step 1:-Declare a class called Rational and invoke a function called gcd(a,b).
Step 2:-Find out the reminder when a is divided by b and pass it as a parameter to the function.
Step 3:-Create an object for the class and declare the required string and integer variables.
Step 4:-Create an object of class DataInputStream .Read the numbers through the ReadLine() method into the object.
Step 5:-Convert the input accepted into Integers through the parseInt method and store them in variables a and b.
Step 6:-store the value returned by the function GCD in variable l.
Step 7:-Divide a by l and b by l and store them in variables x and y.
Program:-
import java.io.*;class rational1{ public rational1(){}
public long gcd(long a,long b){
if(b==0)return a;
elsereturn gcd(b,a%b);
}}public class rational{
public static void main(String args[])throws IOException{
rational1 r=new rational1();long a,b,x,y;String str;DataInputStream in= new DataInputStream(System.in);System.out.println("Enter the value for A");str=in.readLine();a=Integer.parseInt(str);System.out.println("Enter the value for B");str=in.readLine();b=Integer.parseInt(str);
long l=r.gcd(a,b);System.out.println();System.out.println("The GCD of the number is:"+l); x=a/l;y=b/l;System.out.println();System.out.println("The resultant value is: "+x+"/"+y);
}}
Output
Enter the value for A500Enter the value for B1000
The GCD of the number is:500
The resultant value is: 1/2Ex No 2: Date Class in Java
AIM
To design a Date class in Java .
ALGORITHM:-
Step 1:Declare a class called Dateexample and create an object called date.
Step 2:-Display the Date and Time through these objects with theMethods in Date Class.
Step 3:-Declare two objects called starttime and endtime for this class .
Step 4:-Create another object called changed object and display the changed time with the calculation 24L*60L*60L*1000L.
Step 5:-In the main function create object for the class Date and display the time and date accordingly.
SOURCE CODE
import java.util.Date;import java.text.ParseException;import java.text.SimpleDateFormat;public class DateExample {
private static void DateExample() {
Date date = new Date(); System.out.println("Current Date and Time is : " + date); System.out.println();
System.out.println("Date object showing specific date and time"); Date particulardate1 = new Date(24L*60L*60L*1000L); Date particulardate2 = new Date(0L); System.out.println(); System.out.println("First Particular date : " + particulardate1); System.out.println("Second Particular date: " + particulardate2); System.out.println();
System.out.println("Demo of getTime() method returning milliseconds"); System.out.println(); Date strtime = new Date(); System.out.println("Start Time: " + strtime); Date endtime = new Date(); System.out.println("End Time is: " + endtime); long elapsed_time = endtime.getTime() - strtime.getTime(); System.out.println("Elapsed Time is:" + elapsed_time + " milliseconds"); System.out.println();
System.out.println("Changed date object using setTime() method"); System.out.println(); Date chngdate = new Date(); System.out.println("Date before change is: " + chngdate); chngdate.setTime(24L*60L*60L*1000L); System.out.println("Now the Changed date is: " + chngdate); System.out.println(); }
public static void main(String[] args) { System.out.println(); DateExample(); }
}
OUTPUT
Current Date and Time is : Mon Dec 10 18:39:27 GMT+05:30 2007
Date object showing specific date and time
First Particular date : Fri Jan 02 05:30:00 GMT+05:30 1970Second Particular date: Thu Jan 01 05:30:00 GMT+05:30 1970
Demo of getTime() method returning milliseconds
Start Time: Mon Dec 10 18:39:28 GMT+05:30 2007End Time is: Mon Dec 10 18:39:28 GMT+05:30 2007Elapsed Time is:0 milliseconds
Changed date object using setTime() method
Date before change is: Mon Dec 10 18:39:28 GMT+05:30 2007Now the Changed date is: Fri Jan 02 05:30:00 GMT+05:30 1970
Ex4 : Implementation of Stack ADT
AIM
To write a Java Program to design an interface for Stack ADT.and implement Stack ADT using both Array and Linked List.
ALGORITHM
Step 1:Declare an array for storing the stack elements and initialise the capacity of the array.
Step 2:-Declare functions makeempty(),isempty() to check whether the stack is empty to insert an element.
Step 3:After inserting an element,increment the counter by 1 to increase the number of elements in stack.
Step 4:Initiate another array to extend the size of the array when the number of elements exceed beyond the limit.
Step 5:-Invoke methods and constructors to implement the stack using linked list.
Step 6:-Test if the stack is logically empty.then return true or else false.
Step 7:To delete an element from stack,check if stack is empty,if so throw an exception or else move to the next element in the stack.
Step 8:To return the most recently inserted element use the method topOfStack() and then move the pointer to the next element.
Step 9:Declare a stack Interface to push and pop elements from stack.
Step 10:create two objects one for array and other for linked list implementation of stack.
Step 11:Insert characters and numbers into the stack using the methods and display the inserted elements with exception blocks.
SOURCE CODE
/** * Array-based implementation of the stack.*/public class ArrayStack implements Stack {
private Object [ ] theArray; private int topOfStack; private static final int DEFAULT_CAPACITY = 10;
/** * Construct the stack. */ public ArrayStack( ) { theArray = new Object[ DEFAULT_CAPACITY ]; topOfStack = -1; } /** * Test if the stack is logically empty. * @return true if empty, false otherwise. */ public boolean isEmpty( ) { return topOfStack == -1; } /** * Make the stack logically empty. */ public void makeEmpty( ) { topOfStack = -1; } /** * Get the most recently inserted item in the stack. * Does not alter the stack. * @return the most recently inserted item in the stack. * @throws UnderflowException if the stack is empty. */ public Object top( ) { if( isEmpty( ) ) throw new UnderflowException( "ArrayStack top" ); return theArray[ topOfStack ]; } /** * Remove the most recently inserted item from the stack. * @throws UnderflowException if the stack is empty. */
public void pop( ) { if( isEmpty( ) ) throw new UnderflowException( "ArrayStack pop" ); topOfStack--; } /** * Return and remove the most recently inserted item * from the stack. * @return the most recently inserted item in the stack. * @throws Underflow if the stack is empty. */ public Object topAndPop( ) { if( isEmpty( ) ) throw new UnderflowException( "ArrayStack topAndPop" ); return theArray[ topOfStack-- ]; } /** * Insert a new item into the stack. * @param x the item to insert. */ public void push( Object x ) { if( topOfStack + 1 == theArray.length ) doubleArray( ); theArray[ ++topOfStack ] = x; } /** * Internal method to extend theArray. */ private void doubleArray( ) { Object [ ] newArray; newArray = new Object[ theArray.length * 2 ]; for( int i = 0; i < theArray.length; i++ ) newArray[ i ] = theArray[ i ]; theArray = newArray; } }
//ListStack class//// CONSTRUCTION: with no initializer//// ******************PUBLIC OPERATIONS*********************// void push( x ) --> Insert x// void pop( ) --> Remove most recently inserted item// Object top( ) --> Return most recently inserted item// Object topAndPop( ) --> Return and remove most recent item// boolean isEmpty( ) --> Return true if empty; else false// void makeEmpty( ) --> Remove all items// ******************ERRORS********************************// top, pop, or topAndPop on empty stack
/** * List-based implementation of the stack.*/public class LinkedListStack implements Stack {
/** * Construct the stack. */public LinkedListStack( ) {
topOfStack = null;}
/** * Test if the stack is logically empty. * @return true if empty, false otherwise. */public boolean isEmpty( ) {
return topOfStack == null;}
/** * Make the stack logically empty. */public void makeEmpty( ) {
topOfStack = null;}
/** * Insert a new item into the stack. * @param x the item to insert. */public void push( Object x ) {
topOfStack = new ListNode( x, topOfStack );}
/** * Remove the most recently inserted item from the stack.
* @throws UnderflowException if the stack is empty. */public void pop( ) {
if( isEmpty( ) )throw new UnderflowException( "ListStack pop" );
topOfStack = topOfStack.next;}
/** * Get the most recently inserted item in the stack. * Does not alter the stack. * @return the most recently inserted item in the stack. * @throws UnderflowException if the stack is empty. */public Object top( ) {
if( isEmpty( ) )throw new UnderflowException( "ListStack top" );
return topOfStack.element;}
/** * Return and remove the most recently inserted item * from the stack. * @return the most recently inserted item in the stack. * @throws UnderflowException if the stack is empty. */public Object topAndPop( ) {
if( isEmpty( ) )throw new UnderflowException( "ListStack topAndPop"
);
Object topItem = topOfStack.element;topOfStack = topOfStack.next;return topItem;
}
private ListNode topOfStack;
}
public class ListNode {public Object element;public ListNode next;
// Constructorspublic ListNode( Object theElement ) {
this( theElement, null );}
public ListNode( Object theElement, ListNode n ) {
element = theElement;next = n;
}}
public interface Stack {/** * Insert a new item into the stack. * @param x the item to insert. */void push( Object x );
/** * Remove the most recently inserted item from the stack. * @exception UnderflowException if the stack is empty. */void pop( );
/** * Get the most recently inserted item in the stack. * Does not alter the stack. * @return the most recently inserted item in the stack. * @exception UnderflowException if the stack is empty. */Object top( );
/** * Return and remove the most recently inserted item * from the stack. * @return the most recently inserted item in the stack. * @exception UnderflowException if the stack is empty. */Object topAndPop( );
/** * Test if the stack is logically empty. * @return true if empty, false otherwise. */boolean isEmpty( );
/** * Make the stack logically empty. */void makeEmpty( );
}
public class StackTester {
public static void main(String[] args) {
System.out.println("******************************************");System.out.println("Stack using Array & Linked List
example");
System.out.println("******************************************");
ArrayStack arrayStack = new ArrayStack();arrayStack.push(new String("a"));arrayStack.push(new String("b"));arrayStack.push(new String("c"));System.out.println("Stack[using array] elements -> a, b,
c");System.out.println("Stack LIFO and POP ->
"+arrayStack.topAndPop());System.out.println("Stack LIFO -> "+arrayStack.top());arrayStack.pop();try{
arrayStack.pop();arrayStack.topAndPop();
}catch(RuntimeException rte){System.err.println("Exception occured while POP
operation is happened on Stack[by using array]");}System.out.println("\n\n******************************");System.out.println("Stack using Linked List example");System.out.println("******************************");
LinkedListStack linkedListStack = new LinkedListStack();linkedListStack.push(new Integer(10));linkedListStack.push(new Integer(20));linkedListStack.push(new Integer(30));linkedListStack.push(new Integer(40));System.out.println("Stack[using linked list] elements ->
10, 20, 30, 40");System.out.println("Stack TOP ->"+linkedListStack.top());linkedListStack.pop();System.out.println("Stack TOP after POP -
>"+linkedListStack.top());linkedListStack.pop();linkedListStack.pop();linkedListStack.pop();try{
linkedListStack.pop();}catch(RuntimeException rte){
System.err.println("Exception occured while POP operation is happened on Stack[by using linked list]");
}
}}
/** * Exception class for access in empty containers * such as stacks, queues, and priority queues. * @author Ramkumar */public class UnderflowException extends RuntimeException {
/** * Construct this exception object. * @param message the error message. */public UnderflowException( String message ) {
super( message );}
}
OUTPUT
Stack using Array & Linked List example******************************************Stack[using array] elements -> a, b, cStack LIFO and POP -> cStack LIFO -> bException occured while POP operation is happened on Stack[by using array]
******************************Stack using Linked List example******************************Stack[using linked list] elements -> 10, 20, 30, 40Stack TOP ->40Stack TOP after POP ->30Exception occured while POP operation is happened on Stack[by using linked list]
Ex no:5 Polymorphism
Aim:- To develop a vehicle class hierarchy in Java to demonstrate the concept of polymorphism.
Algorithm:-
Step 1:-Declare a super class called vehicle with data elements doors,wheels and seats.
Step 2:-Derive another class called car and invoke a function tostring() to display the variables.
Step 3:-Derive another class called motorcycle with same data and method called setseats() .
Step 4:-Declare another sub class called Truck with 2 constructors and finally assign values to variables.
Step 5:-In the main function, create an object for class motorcycle and display all details of sub classes through object.
Sourcecode:-
//This is the class that will be inheritedpublic class Vehicle{ public int doors; public int seats; public int wheels; Vehicle() {
wheels=4; doors=4;
seats=4; }}//This class inherits Vehicle.javapublic class Car extends Vehicle{
public String toString() {
return "This car has "+seats+" Seats, "+doors+" Doors "+ "and "+wheels+" wheels.";
}}//This class inherits Vehicle.javapublic class MotorCycle extends Vehicle{ MotorCycle() {
wheels=2; doors=0;
seats=1; } void setSeats(int num) {
seats=num; } public String toString() {
return "This motorcycle has "+seats+" Seats, "+doors+" Doors "+ "and "+wheels+" wheels.";
}}//This class inherits Vehicle.javapublic class Truck extends Vehicle{ boolean isPickup; Truck() {
isPickup=true; } Truck(boolean aPickup) {
this();isPickup=aPickup;
} Truck(int doors, int seats, int inWheels, boolean isPickup) {
this.doors=doors;this.seats=seats;wheels=inWheels;this.isPickup=isPickup;
} public String toString() {
return "This "+(isPickup?"pickup":"truck")+ " has "+seats+" Seats, "+doors+" Doors "+"and "+wheels+"
wheels."; }}//This class tests the classes that inherit Vehicle.javapublic class VehiclesTest{ public static void main(String args[]) {
MotorCycle mine = new MotorCycle();System.out.println(mine);Car mine2 = new Car();System.out.println(mine2);mine2.doors=2;System.out.println(mine2);Truck mine3 = new Truck();System.out.println(mine3);Truck mine4 = new Truck(false);mine4.doors=2;System.out.println(mine4);
}}
Output
This motorcycle has 1 Seats, 0 Doors and 2 wheelsThis car has 4 Seats, 4 Doors and 4 wheelsThis car has 4 Seats, 2 Doors and 4 wheelsThis pickup has 4 Seats, 4 Doors and 4 wheelsThis truck has 4 Seats, 2 Doors and 4 wheels
Ex No:-6 Object Serialization
Aim:-To write a Java Program to randomly generate objects and write them into a file using concept of Object Serialization.
Algorithm:-
Step 1:Declare a class called Currency .Open a file in output mode with a name.
Step 2:-Write new data into the object using writeobject() method.
Step 3:-Similarly create an input stream object .Read it both in terms of Dollars and Rupees.close the output object.
Step 4:-derive a class called Dollar which implements serializable interface.Invoke a constructor and function to display the data.
Step 5:Similarly declare a class called Rupee with private variables and use print function to display the variables.
Step 6:terminate the execution.The output is displayed as dollar to rupee conversion and vice versa.
Sourcecode:-
// Currency conversionimport java.io.*;public class Currency{ public static void main(String args[]) { Dollar dr=new Dollar('$',40); dr.printDollar(); Rupee re=new Rupee("Rs.",50); re.printRupee(); try { File f=new File("rd.txt"); FileOutputStream fos=new FileOutputStream(f); ObjectOutputStream oos=new ObjectOutputStream(fos); oos.writeObject(dr); oos.writeObject(re); oos.flush(); oos.close(); ObjectInputStream ois=new ObjectInputStream(new FileInputStream("rd.txt")); Dollar d1; d1=(Dollar)ois.readObject(); d1.printDollar(); Rupee r1; r1=(Rupee)ois.readObject(); r1.printRupee(); ois.close(); } catch(Exception e) { } } }class Dollar implements Serializable{ private float dol; private char sym;
public Dollar(char sm,float doll) { sym=sm; dol=doll; } void printDollar() { System.out.print(sym); System.out.println(dol); }}class Rupee implements Serializable{ private String sym; private float rs; public Rupee(String sm,float rup) { sym=sm; rs=rup; } void printRupee() { System.out.print(sym); System.out.println(rs); }
}
Output:-
E:\java>java Currency$40.0Rs.50.0$40.0Rs.50.0
Ex No:7 Event-Driven Programming
AIM
To develop a scientific calculator using even-driven programming paradigm of Java.
ALGORITHM:
Step 1:-Import all the packages required for designing the graphical elements in the applet window.
Step 2:-Implement the Listener files for Keyboard, mouse events in the class defined.
Step 3:-Import the swing package in the program for using swing components for thr gridLayout design for menu,Frame,Dialog ,TextArea,Label and other components for alignment in the applet window.
Step 4:-Create objects from the main classes for JLabel,Jtextbox,JPanel ,Font and Menu items.
Step 5:Assign the font items to all the menu items and add them to the panel.
Step 6:-Create the GridBagLayout and add all the buttons to it using the swing class.
Step 7:-Add all the JButtons to the panel and also the colour components to the GUI controls.
Step 8:-Call adddighitstodisplay() to activate the required arithmetic operations when the buttons are pressed.
Step 9:Invoke the function displayresult() to store the result of the values computed.
Step 10:-Handle the divide by zero exception outside the class definition. And create an object for the class created.
Step 11:-Add all the methods,properties and layout to the panel window and display the result in the textarea created.
Step 12:-Invoke the actionPerformed() method through the ActionEvent class and write code for each operator or number being pressed.
SOURCE CODE:=-
import java.awt.BorderLayout;import java.awt.Color;import java.awt.Container;import java.awt.FlowLayout;import java.awt.Font;import java.awt.GridLayout;import java.awt.Window;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.KeyEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;
import javax.swing.JButton;import javax.swing.JDialog;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JMenuItem;import javax.swing.JPanel;import javax.swing.JTextArea;import javax.swing.KeyStroke;
public class Calculator extends JFrame implements ActionListener {
// Variables
final int MAX_INPUT_LENGTH = 20;final int INPUT_MODE = 0;final int RESULT_MODE = 1;final int ERROR_MODE = 2;int displayMode;
boolean clearOnNextDigit, percent;double lastNumber;String lastOperator;
private JMenu jmenuFile, jmenuHelp;private JMenuItem jmenuitemExit, jmenuitemAbout;
private JLabel jlbOutput;
private JButton jbnButtons[];private JPanel jplMaster, jplBackSpace, jplControl;
/* * Font(String name, int style, int size)
Creates a new Font from the specified name, style and point size.
*/
Font f12 = new Font("Times New Roman", 0, 12);Font f121 = new Font("Times New Roman", 1, 12);
// Constructor public Calculator() {
/* Set Up the JMenuBar. * Have Provided All JMenu's with Mnemonics * Have Provided some JMenuItem components with Keyboard
Accelerators */
jmenuFile = new JMenu("File");jmenuFile.setFont(f121);jmenuFile.setMnemonic(KeyEvent.VK_F);
jmenuitemExit = new JMenuItem("Exit");jmenuitemExit.setFont(f12);
jmenuitemExit.setAccelerator(KeyStroke.getKeyStroke( KeyEvent.VK_X,
ActionEvent.CTRL_MASK));jmenuFile.add(jmenuitemExit);
jmenuHelp = new JMenu("Help");jmenuHelp.setFont(f121);jmenuHelp.setMnemonic(KeyEvent.VK_H);
jmenuitemAbout = new JMenuItem("About Calculator");jmenuitemAbout.setFont(f12);jmenuHelp.add(jmenuitemAbout);
JMenuBar mb = new JMenuBar();mb.add(jmenuFile);mb.add(jmenuHelp);setJMenuBar(mb);
//Set frame layout manager
setBackground(Color.gray);
jplMaster = new JPanel();
jlbOutput = new JLabel("0");
jlbOutput.setHorizontalTextPosition(JLabel.RIGHT);jlbOutput.setBackground(Color.WHITE);jlbOutput.setOpaque(true);
// Add components to framegetContentPane().add(jlbOutput, BorderLayout.NORTH);
jbnButtons = new JButton[23];// GridLayout(int rows, int cols, int hgap, int vgap)
JPanel jplButtons = new JPanel(); // container for Jbuttons
// Create numeric Jbuttonsfor (int i=0; i<=9; i++){
// set each Jbutton label to the value of indexjbnButtons[i] = new JButton(String.valueOf(i));
}
// Create operator JbuttonsjbnButtons[10] = new JButton("+/-");jbnButtons[11] = new JButton(".");jbnButtons[12] = new JButton("=");jbnButtons[13] = new JButton("/");jbnButtons[14] = new JButton("*");jbnButtons[15] = new JButton("-");jbnButtons[16] = new JButton("+");jbnButtons[17] = new JButton("sqrt");jbnButtons[18] = new JButton("1/x");jbnButtons[19] = new JButton("%");
jplBackSpace = new JPanel();jplBackSpace.setLayout(new GridLayout(1, 1, 2, 2));
jbnButtons[20] = new JButton("Backspace");jplBackSpace.add(jbnButtons[20]);
jplControl = new JPanel();jplControl.setLayout(new GridLayout(1, 2, 2 ,2));
jbnButtons[21] = new JButton(" CE ");jbnButtons[22] = new JButton("C");
jplControl.add(jbnButtons[21]);jplControl.add(jbnButtons[22]);
// Setting all Numbered JButton's to Blue. The rest to Redfor (int i=0; i<jbnButtons.length; i++) {
jbnButtons[i].setFont(f12);
if (i<10)jbnButtons[i].setForeground(Color.blue);
elsejbnButtons[i].setForeground(Color.red);
}
// Set panel layout manager for a 4 by 5 gridjplButtons.setLayout(new GridLayout(4, 5, 2, 2));
//Add buttons to keypad panel starting at top left// First rowfor(int i=7; i<=9; i++) {
jplButtons.add(jbnButtons[i]);}
// add button / and sqrtjplButtons.add(jbnButtons[13]);jplButtons.add(jbnButtons[17]);
// Second rowfor(int i=4; i<=6; i++){
jplButtons.add(jbnButtons[i]);}
// add button * and x^2jplButtons.add(jbnButtons[14]);jplButtons.add(jbnButtons[18]);
// Third rowfor( int i=1; i<=3; i++){
jplButtons.add(jbnButtons[i]);}
//adds button - and %jplButtons.add(jbnButtons[15]);jplButtons.add(jbnButtons[19]);
//Fourth Row// add 0, +/-, ., +, and =jplButtons.add(jbnButtons[0]);jplButtons.add(jbnButtons[10]);jplButtons.add(jbnButtons[11]);jplButtons.add(jbnButtons[16]);jplButtons.add(jbnButtons[12]);
jplMaster.setLayout(new BorderLayout());jplMaster.add(jplBackSpace, BorderLayout.WEST);jplMaster.add(jplControl, BorderLayout.EAST);jplMaster.add(jplButtons, BorderLayout.SOUTH);
// Add components to framegetContentPane().add(jplMaster, BorderLayout.SOUTH);requestFocus();
//activate ActionListenerfor (int i=0; i<jbnButtons.length; i++){
jbnButtons[i].addActionListener(this);}
jmenuitemAbout.addActionListener(this);jmenuitemExit.addActionListener(this);
clearAll();
//add WindowListener for closing frame and ending programaddWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e){
System.exit(0);}
});
} //End of Contructor Calculator
// Perform actionpublic void actionPerformed(ActionEvent e){
double result = 0;
if(e.getSource() == jmenuitemAbout){ JDialog dlgAbout = new CustomABOUTDialog(this,
"About Java Swing Calculator", true);
dlgAbout.setVisible(true);}else if(e.getSource() == jmenuitemExit){
System.exit(0);}
// Search for the button pressed until end of array or key found
for (int i=0; i<jbnButtons.length; i++){
if(e.getSource() == jbnButtons[i]){
switch(i){
case 0:addDigitToDisplay(i);break;
case 1:addDigitToDisplay(i);break;
case 2:addDigitToDisplay(i);break;
case 3:addDigitToDisplay(i);break;
case 4:addDigitToDisplay(i);break;
case 5:addDigitToDisplay(i);break;
case 6:addDigitToDisplay(i);break;
case 7:addDigitToDisplay(i);break;
case 8:addDigitToDisplay(i);break;
case 9:addDigitToDisplay(i);break;
case 10: // +/-processSignChange();break;
case 11: // decimal pointaddDecimalPoint();break;
case 12: // =processEquals();break;
case 13: // divideprocessOperator("/");break;
case 14: // *processOperator("*");break;
case 15: // -processOperator("-");break;
case 16: // +processOperator("+");
break;
case 17: // sqrtif (displayMode != ERROR_MODE){ try
{if
(getDisplayString().indexOf("-") == 0)
displayError("Invalid input for function!");
result = Math.sqrt(getNumberInDisplay());displayResult(result);
}
catch(Exception ex){
displayError("Invalid input for function!”);displayMode = ERROR_MODE;
}}break;
case 18: // 1/xif (displayMode != ERROR_MODE){
try{
if (getNumberInDisplay() == 0)
displayError("Cannot divide by zero!");
result = 1 / getNumberInDisplay();
displayResult(result);}
catch(Exception ex) {displayError("Cannot
divide by zero!");displayMode =
ERROR_MODE;}
}break;
case 19: // %if (displayMode != ERROR_MODE){
try {result =
getNumberInDisplay() / 100;displayResult(result);
}
catch(Exception ex) {displayError("Invalid
input for function!");displayMode =
ERROR_MODE;}
}break;
case 20: // backspaceif (displayMode != ERROR_MODE){
setDisplayString(getDisplayString().substring(0,
getDisplayString().length() - 1));
if (getDisplayString().length() < 1)
setDisplayString("0");}break;
case 21: // CEclearExisting();break;
case 22: // CclearAll();break;
}}
}}
void setDisplayString(String s){jlbOutput.setText(s);
}
String getDisplayString (){return jlbOutput.getText();
}
void addDigitToDisplay(int digit){if (clearOnNextDigit)
setDisplayString("");
String inputString = getDisplayString();
if (inputString.indexOf("0") == 0){inputString = inputString.substring(1);
}
if ((!inputString.equals("0") || digit > 0)
&& inputString.length() < MAX_INPUT_LENGTH){
setDisplayString(inputString + digit);}
displayMode = INPUT_MODE;clearOnNextDigit = false;
}
void addDecimalPoint(){displayMode = INPUT_MODE;
if (clearOnNextDigit)setDisplayString("");
String inputString = getDisplayString();
// If the input string already contains a decimal point, don't
// do anything to it.if (inputString.indexOf(".") < 0)
setDisplayString(new String(inputString + "."));}
void processSignChange(){if (displayMode == INPUT_MODE){
String input = getDisplayString();
if (input.length() > 0 && !input.equals("0")){
if (input.indexOf("-") == 0)setDisplayString(input.substring(1));
elsesetDisplayString("-" + input);
}
}
else if (displayMode == RESULT_MODE){
double numberInDisplay = getNumberInDisplay();
if (numberInDisplay != 0)displayResult(-numberInDisplay);
}}
void clearAll() {setDisplayString("0");lastOperator = "0";lastNumber = 0;
displayMode = INPUT_MODE;clearOnNextDigit = true;
}
void clearExisting(){setDisplayString("0");clearOnNextDigit = true;displayMode = INPUT_MODE;
}
double getNumberInDisplay() {String input = jlbOutput.getText();return Double.parseDouble(input);
}
void processOperator(String op) {if (displayMode != ERROR_MODE){
double numberInDisplay = getNumberInDisplay();
if (!lastOperator.equals("0")){
try{
double result = processLastOperator();displayResult(result);lastNumber = result;
}
catch (DivideByZeroException e){}
}
else{
lastNumber = numberInDisplay;}
clearOnNextDigit = true;lastOperator = op;
}}
void processEquals(){double result = 0;
if (displayMode != ERROR_MODE){try{
result = processLastOperator();displayResult(result);
}
catch (DivideByZeroException e) {displayError("Cannot divide by zero!");
}
lastOperator = "0";}
}
double processLastOperator() throws DivideByZeroException {double result = 0;double numberInDisplay = getNumberInDisplay();
if (lastOperator.equals("/")){
if (numberInDisplay == 0)throw (new DivideByZeroException());
result = lastNumber / numberInDisplay;}
if (lastOperator.equals("*"))result = lastNumber * numberInDisplay;
if (lastOperator.equals("-"))result = lastNumber - numberInDisplay;
if (lastOperator.equals("+"))result = lastNumber + numberInDisplay;
return result;}
void displayResult(double result){setDisplayString(Double.toString(result));lastNumber = result;displayMode = RESULT_MODE;clearOnNextDigit = true;
}
void displayError(String errorMessage){setDisplayString(errorMessage);lastNumber = 0;displayMode = ERROR_MODE;clearOnNextDigit = true;
}
public static void main(String args[]) {Calculator calci = new Calculator();Container contentPane = calci.getContentPane();
// contentPane.setLayout(new BorderLayout());calci.setTitle("Java Swing Calculator");calci.setSize(241, 217);calci.pack();calci.setLocation(400, 250);
calci.setVisible(true);calci.setResizable(false);
}
} //End of Swing Calculator Class.
class DivideByZeroException extends Exception{public DivideByZeroException(){
super();}
public DivideByZeroException(String s){
super(s);}
}
class CustomABOUTDialog extends JDialog implements ActionListener {JButton jbnOk;
CustomABOUTDialog(JFrame parent, String title, boolean modal){super(parent, title, modal);setBackground(Color.black);
JPanel p1 = new JPanel(new FlowLayout(FlowLayout.CENTER));
StringBuffer text = new StringBuffer();text.append("Calculator Demo Program\n\n");
JTextArea jtAreaAbout = new JTextArea(5, 21);jtAreaAbout.setText(text.toString());jtAreaAbout.setFont(new Font("Times New Roman", 1, 13));jtAreaAbout.setEditable(false);
p1.add(jtAreaAbout);p1.setBackground(Color.red);getContentPane().add(p1, BorderLayout.CENTER);
JPanel p2 = new JPanel(new FlowLayout(FlowLayout.CENTER));
jbnOk = new JButton(" OK ");jbnOk.addActionListener(this);
p2.add(jbnOk);getContentPane().add(p2, BorderLayout.SOUTH);
setLocation(408, 270);setResizable(false);
addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e)
{Window aboutDialog = e.getWindow();aboutDialog.dispose();}});
pack();}
public void actionPerformed(ActionEvent e){if(e.getSource() == jbnOk) {this.dispose();}}
}
OUTPUT
EX NO:-8 Multithreading
Aim:-
To write a multi-threaded Java program to print all numbers below 100,000 that are both prime and Fibonacci number (some examples are 2, 3, 5, 13, etc.). Design a thread that generates prime numbers below 100,000 and writes them into a pipe. Design another thread that generates fibonacci numbers and writes them to another pipe.The main thread should read both the pipes to identify numbers common to both.
ALGORITHM:
Step 1:-Include Dataoutputstream and pipedOutputStream Classes in the program to accept numbers as input from user.
Step 2:-Create an object for class DataOutputStream to display the data. Step 3:-Invoke the run() method to initiate the FOR loop and write the data into the object.
Step 4:Create a function called Fibonacci() and assign the previous,next and final values to display the series.
Step 5:-Create two objects for PipedInputStream and PipedOutputStream and inherit from the Thread class to generate prime numbers.
Step 6:Start the threads and handle the exceptions through the try-catch block.
Step 7:-Call the super class method in the subclass and give the code to check for the condition required for a number to be prime inside the run() method of the Thread class.
Step 8:-Write the list of prime numbers into the object created.Create another thread using the Thread class to write the Fibonacci series into another pipe.
Step 9:-Call the main thread in the main function through the ThreadGroup and read the data from the two separate objects for Fibonacci numbers and prime numbers.Identify the
numbers common to both an dfinally display them.
SOURCE CODE
import java.io.DataOutputStream;import java.io.IOException;import java.io.PipedOutputStream;
public class FibonacciNumberGenerator extends Thread {private DataOutputStream dos;
public FibonacciNumberGenerator(ThreadGroup threadGroup ,PipedOutputStream pis, String name){
super(threadGroup, name);dos = new DataOutputStream(pis);
}
@Overridepublic void run() {
try {for(int k=0; k<10000; k++){
long fibonacciNum = fib(k);if(fibonacciNum > 0L && fibonacciNum <
10000L){dos.writeLong(fibonacciNum);dos.flush();
}}
} catch (IOException e) {}
}
public int fib(int n) {int prev1=0, prev2=1;for(int i=0; i<n; i++) {
int savePrev1 = prev1;prev1 = prev2;prev2 = savePrev1 + prev2;
}return prev1;
}
}
import java.io.DataInputStream;import java.io.IOException;import java.io.PipedInputStream;import java.io.PipedOutputStream;
public class PipedStreamTester extends Thread {
DataInputStream fibonicPis;DataInputStream primePis;
public PipedStreamTester(PipedInputStream fibonicPis, PipedInputStream primePis){
this.fibonicPis = new DataInputStream(fibonicPis);this.primePis = new DataInputStream(primePis);
}
public static void main(String[] args) {try {
PipedOutputStream fibonicPos = new PipedOutputStream();
PipedInputStream fibonicPis = new PipedInputStream(fibonicPos);
PipedOutputStream primePos = new PipedOutputStream();
PipedInputStream primePis = new PipedInputStream(primePos);
ThreadGroup tg = new ThreadGroup("PipedThreads");FibonacciNumberGenerator f = new
FibonacciNumberGenerator(tg, fibonicPos, "FibonacciNumberGenerator");
PrimeNumberGenerator p = new PrimeNumberGenerator(tg, primePos, "PrimeNumberGenerator");
PipedStreamTester mainTester = new PipedStreamTester(fibonicPis, primePis);
mainTester.start();f.start();p.start();
} catch (IOException e) {e.printStackTrace();
}
}
/* (non-Javadoc) * @see java.lang.Thread#run()
*/@Overridepublic void run() {
boolean canRun = true;boolean canGoPrimeLoop = true;boolean canGoFibonicLoop = true;Long primeNumber = -1L;Long fibonacciNumber = -1L;while(canRun){
if(fibonicPis != null && canGoFibonicLoop){
try {fibonacciNumber = fibonicPis.readLong();System.out.println(" Fibonic Number
#>"+fibonacciNumber);
} catch (IOException e) {//System.err.println("Exception occurred
while reading from fibonacci number, "+e);canGoFibonicLoop = false;
}}
if(primePis != null && canGoPrimeLoop){try {
primeNumber = primePis.readLong();System.out.println(" Prime Number
#>"+primeNumber);
} catch (IOException e) {//System.err.println("Exception occurred
while reading from prime number, "+e);canGoPrimeLoop = false;
}}
}}
}
import java.io.DataOutputStream;import java.io.IOException;import java.io.PipedOutputStream;
public class PrimeNumberGenerator extends Thread {
private DataOutputStream dos;public PrimeNumberGenerator (ThreadGroup threadGroup,
PipedOutputStream pos, String name){super(threadGroup, name);dos = new DataOutputStream(pos);
}
@Overridepublic void run() {
try {int x, y, c = 0;for( x = 2; x < 10000; x++ ){
if( x % 2 != 0 || x == 2 ){for( y = 2; y <= x / 2; y++ ){
if( x % y == 0 ){break;
}}if( y > x / 2 ){
if(x < 10000){dos.writeLong(x);dos.flush();
}}
}}
} catch (IOException e) {}
}}
OUTPUT
Fibonic Number #>1 Prime Number #>2 Fibonic Number #>1 Prime Number #>3 Fibonic Number #>2 Prime Number #>5 Fibonic Number #>3 Prime Number #>7 Fibonic Number #>5 Prime Number #>11 Fibonic Number #>8 Prime Number #>13 Fibonic Number #>13 Prime Number #>17 Fibonic Number #>21 Prime Number #>19 Fibonic Number #>34 Prime Number #>23 Fibonic Number #>55 Prime Number #>29
Fibonic Number #>89 Prime Number #>31 Fibonic Number #>144 Prime Number #>37 Fibonic Number #>233 Prime Number #>41 Fibonic Number #>377 Prime Number #>43 Fibonic Number #>610 Prime Number #>47 Fibonic Number #>987 Prime Number #>53 Fibonic Number #>1597 Prime Number #>59 Fibonic Number #>2584 Prime Number #>61 Fibonic Number #>4181 Prime Number #>67 Fibonic Number #>6765 Prime Number #>71 Prime Number #>73 Prime Number #>79 Prime Number #>83 Prime Number #>89 Prime Number #>97 Prime Number #>101 Prime Number #>103 Prime Number #>107 Prime Number #>109 Prime Number #>113 Prime Number #>127 Prime Number #>131 Prime Number #>137 Prime Number #>139 Prime Number #>149 Prime Number #>151 Prime Number #>157 Prime Number #>163 Prime Number #>167 Prime Number #>173 Prime Number #>179 Prime Number #>181 Prime Number #>191 Prime Number #>193 Prime Number #>197 Prime Number #>199 Prime Number #>211 Prime Number #>223 Prime Number #>227 Prime Number #>229 Prime Number #>233 Prime Number #>239
Prime Number #>241 Prime Number #>251 Prime Number #>257 Prime Number #>263 Prime Number #>269 Prime Number #>271 Prime Number #>277 Prime Number #>281 Prime Number #>283 Prime Number #>293 Prime Number #>307 Prime Number #>311 Prime Number #>313 Prime Number #>317 Prime Number #>331 Prime Number #>337
Ex No:9 Java Database Connectivity
Aim:-To develop a simple OPAC System for library management system using event-driven and concurrent programming paradigms and java database connectivity.
Algorithm:-
Step 1:Initiate a class and declare the driver for the Driver name required to connect to the database.
Step 2:-Enclose the coding in a try block to handle errors and trap the exception in a catch block.
Step 3:-Establish the connection object to connect to the backend.
Step 4:-Create an object for Statement object using createStatement() object.
Step 5:-Issue a query through executeQuery() method.
Source code:-
Import java.awt.*;Import javax.swing.*;Import java.awt.event.*;Import java.sql.*;Public class Jdbcapplet extends JApplet implements ActionListener,ItemListener{JTextField t1,t2;Container contentPane=getContentPane();JLabel l1,l2,l3;JButton save;JPanel p1,p2;JCheckBox c[];String selected=””;Public void init(){contentPane.setLayout(new FlowLayout());T1=new JTextField(20);T2=new JTextField(20);L1=new JLabel(“enter name:”);L2=new JLabel(“enter occupation”);P1=new JPanel();P1.setLayout(new GridLayout(2,2));P1.add(l1);P1.add(t1);P1.add(l2);P1.add(t2);P2=new JPanel();P2.setLayout(new GridLayout(8,1));P2.add(new JLabel(“which os do u use?”));C=new JCheckbox[6];For(int i=0;i<=5;i++){C[i]=new JCheckBox(“”,false);P2.add(c[i]);C[i].addItemListener(this);}C[0].setText(“complete reference”);;
Ex:10.Multi-threaded Echo Server and Client in Java.
Aim:-To develop a Java Program that supports multithreaded echo server and a GUI client.
Algorithm:-
Step 1:-Import the net package which supports networking features in Java.
Step 2:-Write the input data into an object from the keyboard through BufferedStream class.
Step 3:-Create a new object for Socket s and Write the input data into another object called dos using writeBytes() method.
Step 4:-Read the copied string into br using readLine() method and close the file.
Step 5:-On executing the program,the server sends a message to the client.
Step 6:-For the server side program, create an object for ServerSocket class and write input data into it.
Step 7:-Write the data into the dataoutputstream object dos.
Step 8:-close the object and socket.
// Client Program:-
import java.net.*;import java.io.*;class Client{ public static void main(String args[])throws IOException { Socket soc=null; String str=null; BufferedReader br=null; DataOutputStream dos=null; BufferedReader kyrd=new BufferedReader(new InputStreamReader(System.in)); try { soc=new Socket(InetAddress.getLocalHost(),95); br=new BufferedReader(new InputStreamReader(soc.getInputStream())); dos=new DataOutputStream(soc.getOutputStream()); } catch(UnknownHostException uhe)
{ System.out.println("Unknown Host"); System.exit(0); } System.out.println("To start the dialog type the message in this client window \n Type exit to end"); boolean more=true; while(more) { str=kyrd.readLine(); dos.writeBytes(str); dos.write(13); dos.write(10); dos.flush(); String s,s1; s=br.readLine(); System.out.println("From server :"+s); if(s.equals("exit")) break; } br.close(); dos.close(); soc.close(); }}Output:-
E:\java>java ClientTo start the dialog type the message in this client window Type exit to endhelloFrom server :hello
how are youFrom server :how are youhow are youFrom server :how are youexitFrom server :exit
// Server Program
import java.net.*;import java.io.*;class Server{ public static void main(String args[])throws IOException { ServerSocket ss=null; try { ss=new ServerSocket(95); } catch(IOException ioe) { System.out.println("Error finding port"); System.exit(1); } Socket soc=null; try { soc=ss.accept(); System.out.println("Connection accepted at :"+soc); } catch(IOException ioe) { System.out.println("Server failed to accept"); System.exit(1); } DataOutputStream dos=new DataOutputStream(soc.getOutputStream()); BufferedReader br=new BufferedReader(new InputStreamReader(soc.getInputStream())); String s; System.out.println("Server waiting for message from tthe client"); boolean quit=false; do { String msg=""; s=br.readLine(); int len=s.length(); if(s.equals("exit")) quit=true; for(int i=0;i<len;i++) { msg=msg+s.charAt(i); dos.write((byte)s.charAt(i)); }
System.out.println("From client :"+msg); dos.write(13); dos.write(10); dos.flush(); }while(!quit); dos.close(); soc.close();
}}
Output:-
E:\java>java ServerConnection accepted at :Socket[addr=/127.0.0.1,port=49442,localport=95]Server waiting for message from tthe clientFrom client :helloFrom client :how are youFrom client :how are youFrom client :exit
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