java complete manual
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java manualTRANSCRIPT
EX: NO. 1 Rational number class in Java
DATE:
AIM:
To develop a Rational number class in Java, using JavaDoc comments for documentation. The implementation should use efficient representation for a rational number, i.e. (500 / 1000) should be represented as (½).
ALGORITHM:
Step 1: Start the program.Step 2: Define a class with two integer data fields’ numerator and denominator.Step 3: Define a constructor to initialize the rational number and to simplify it.Step 4: Define methods to perform the basic arithmetic operations such as addition, subtraction, multiplication, division and reciprocal.Step 5: Call the appropriate functions with the corresponding arguments and display the result.Step 6: Stop the program.
1
PROGRAM:
import java.io.*;import java.math.*;public class TestRationalClass{
private int num;private int den;
public TestRationalClass(int numerator,int denominator){
if(denominator==0){
throw new RuntimeException("denominator is zero!");}
int g=gcd(numerator,denominator);num=numerator /g;den=denominator /g;}
public String toString(){
if(den==1){
return(num+" ");}else{
return(" "+den);}
}
public TestRationalClass times(TestRationalClass b){
return new TestRationalClass(this.num*b.num,this.den*b.den);}
public TestRationalClass plus(TestRationalClass b){
int numerator=(this.num*b.den)+(this.den*b.num);int denominator=this.den*b.den;return new TestRationalClass(numerator,denominator);
2
}
public TestRationalClass subtract(TestRationalClass b){
int numerator=(this.num*b.den)-(this.den*b.num);int denominator=this.den*b.den;return new TestRationalClass(numerator,denominator);
}
public TestRationalClass reciprocal(){
return new TestRationalClass(den,num);}
public TestRationalClass divides(TestRationalClass b){
return this.times(b.reciprocal());}
private static int gcd(int m,int n){
if(0==n)return m;
elsereturn(gcd(n,m%n));
}
public static void main(String [] args){
TestRationalClass r1=new TestRationalClass(16,2);TestRationalClass r2=new TestRationalClass(12,3);System.out.println("Rational numbers class");System.out.println(r1 +" + "+r2+ " = "+r1.plus(r2));System.out.println(r1 +" - "+r2+ " = "+r1.subtract(r2));System.out.println(r1 +" * "+r2+ " = "+r1.times(r2));System.out.println(r1 +" / "+r2+ " = "+r1.divides(r2));
}}
3
OUTPUT:
RESULT:
Thus the program to develop a rational number class with methods to perform the basic arithmetic operations was executed and the output was verified successfully.
4
EX: NO. 2 Date class in Java DATE:
AIM:
To develop Date class in Java similar to the one available in java.util package. Use JavaDoc comments.
ALGORITHM:
Step 1: Start the program.Step 2: Define an object today to the Date class and store the current date in that object.Step 3: Change the Date Format to Short, Long and Medium and display the date.Step 4: Convert the Date to String and print it.Step 5: Stop the program.
5
PROGRAM:
import java.text.DateFormat;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;public class BasicDateFormatting{
public static void main(String[] args)throws Exception{Date today=Calendar.getInstance().getTime();DateFormat shortFormatter= SimpleDateFormat.getDateInstance(SimpleDateFormat.SHORT);DateFormat longFormatter= SimpleDateFormat.getDateInstance(SimpleDateFormat.LONG);DateFormat mediumFormatter= SimpleDateFormat.getDateTimeInstance(SimpleDateFormat.MEDIUM,SimpleDateFormat.LONG);System.out.println(shortFormatter.format(today));System.out.println(longFormatter.format(today));System.out.println(mediumFormatter.format(today));String DateAsText=shortFormatter.format(today);Date TextAsDate=shortFormatter.parse(DateAsText);System.out.println(TextAsDate);}
}
6
OUTPUT:
RESULT:
Thus the program to develop a Date class was executed and the output was verified successfully.
7
EX: NO. 3 Lisp-like list in Java
DATE:
AIM:
To implement Lisp-like list in Java. To perform the basic operations such as 'car', 'cdr', and 'cons'.
ALGORITHM:
Step 1: Start the program.Step 2: Create a class LispCommands with a list in it.Step 3: Define a function parse to write the elements into the list.Step 4: Define a function car to return the leading element of the list.Step 5: Define a function cdr to return the list starting from the second element.Step 6: Define a function cons which adds an element to the front of the list.Step 7: Call the respective functions with the appropriate arguments.Step 8: Stop the program.
8
PROGRAM:
import java.util.ArrayList;import java.util.Arrays;import java.util.Collections;import java.util.List;import java.util.StringTokenizer;import java.util.logging.Logger;
public class LispCommands {
private String[] tokenList;private static Logger LOGGER =
Logger.getLogger(LispCommands.class.getName());
public LispCommands() {}
private void car() {
LOGGER.info(tokenList[0]);}
private void cdr() {
List<String> list = Arrays.asList(tokenList);ArrayList<String> slist = new ArrayList<String>(list);slist.remove(0);display(slist);
}
private void cons(String args) {
List<String> arrayList = new ArrayList<String>(Arrays.asList(tokenList));
arrayList.add(args);Collections.reverse(arrayList);display(arrayList);
}
private void parse(String args) {
ArrayList<String> tokenList = new ArrayList<String>();if(args != null){
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StringTokenizer tokens = new StringTokenizer(args,"[]");while (tokens.hasMoreElements()) {
StringTokenizer commaTokens = new StringTokenizer(tokens.nextToken(),",");
while (commaTokens.hasMoreElements()) {
String token = commaTokens.nextToken();if(token != null && !token.trim().equals(""))
tokenList.add(token.trim());}
}}this.tokenList = tokenList.toArray(new String[0]);
}
private void display(Object result) {
System.out.println();if(result instanceof String)
LOGGER.info(result.toString());else if(result.getClass().getName().equals("java.util.ArrayList"))
LOGGER.info(result.toString());}
public static void main(String[] args) {
LispCommands L = new LispCommands();L.parse("[3, 0, 2, 5]");L.car();L.cdr();L.cons("7");
}}
10
OUTPUT:
RESULT:
Thus the program to implement Lisp-like list in Java was executed and the output was verified successfully.
11
EX: NO. 4 Design a Java interface for ADT Stack
DATE:
AIM:
To design a Java interface for ADT Stack and to develop two different classes that implements this interface, one using array and the other using linked-list.
ALGORITHM:
Step 1: Start the program.Step 2: Design an interface for Stack ADT with functions push, pop and display.Step 3: Define a class to implement the stack using array.Step 4: Define the functions of the interface accordingly and handle the stack overflow and underflow exceptions.Step 5: Define a class to implement the stack using linked list.Step 6: Define the functions of the interface accordingly and handle the exceptions.Step 7: Stop the program.
12
PROGRAM:
import java.io.*;import java.util.*;interface Mystack{
public void pop();public void push();public void display();
}class Stack_array implements Mystack{
final static int n=5;int stack[]=new int[n];int top=-1;public void push(){
try{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
if(top==(n-1)){
System.out.println(" Stack Overflow");return;
}else{
System.out.println("Enter the element");int ele=Integer.parseInt(br.readLine());stack[++top]=ele;
}}catch(IOException e){
System.out.println("e");}
}public void pop(){
if(top<0){
System.out.println("Stack underflow");return;
}else
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{int popper=stack[top];top--;System.out.println("Popped element:" +popper);
}}
public void display(){
if(top<0){
System.out.println("Stack is empty");return;
}else{
String str=" ";for(int i=0;i<=top;i++)
str=str+" "+stack[i]+" <--";System.out.println("Elements are:"+str);
}}
}class Link { public int data;
public Link nextLink;public Link(int d) {
data= d;nextLink=null;
}public void printLink() {
System.out.print(" --> "+data);}
}class Stack_List implements Mystack{
private Link first;public Stack_List() {
first = null;}public boolean isEmpty() {
14
return first == null;}public void push() {
try{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the element");int ele=Integer.parseInt(br.readLine());
Link link = new Link(ele); link.nextLink = first; first = link;
}catch(IOException e){
System.err.println(e);}
}public Link delete() {
Link temp = first;try{
first = first.nextLink;}catch(NullPointerException e){
throw e;}
return temp;}public void pop(){
try{
Link deletedLink = delete(); System.out.println("Popped: "+deletedLink.data);
}catch(NullPointerException e){
throw e;}
}public void display() {
15
if(first==null)System.out.println("Stack is empty");
else{
Link currentLink = first;System.out.print("Elements are: ");
while(currentLink != null) { currentLink.printLink(); currentLink = currentLink.nextLink;
}System.out.println("");
} }} class StackADT{
public static void main(String arg[])throws IOException{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Implementation of Stack using Array");Stack_array stk=new Stack_array();int ch=0;do{
System.out.println("1.Push 2.Pop 3.Display");System.out.println("Enter your choice:");ch=Integer.parseInt(br.readLine());switch(ch){
case 1:stk.push();break;
case 2:stk.pop();break;
case 3:stk.display();break;
}}while(ch<4);System.out.println("Implementation of Stack using Linked List");Stack_List stk1=new Stack_List();ch=0;do
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{System.out.println("1.Push 2.Pop 3.Display");System.out.println("Enter your choice:");ch=Integer.parseInt(br.readLine());switch(ch){
case 1:stk1.push();break;
case 2:try{
stk1.pop();}catch(NullPointerException e){
System.out.println("Stack underflown");}break;
case 3:stk1.display();break;
}}while(ch<4);
}}
17
OUTPUT:
RESULT:
Thus the program to implement Stack ADT using array and linked list was executed and the output was verified successfully.
18
EX: NO. 5 Design a Vehicle class hierarchy in Java
DATE:
AIM:
To design a Vehicle class hierarchy in Java and to demonstrate polymorphism.
ALGORITHM:
Step 1: Start the program.Step 2: Define a class Vehicle with fields register no. and model.Step 3: Define a method display which displays all the data fields.Step 4: Define the classes namely Twowheeler, Threewheeler and Fourwheeler as subclasses of Vehicle class.Step 5: These subclasses defines a method named display that overrides the super class method.Step 6: Create objects for the subclasses and call the appropriate methods.Step 7: Stop the program.
19
PROGRAM:
import java.io.*;class Vehicle{
String regno;int model;Vehicle(String r, int m){
regno=r;model=m;
}void display(){
System.out.println("Registration no: "+regno);System.out.println("Model no: "+model);
}}
class Twowheeler extends Vehicle{
int noofwheel;Twowheeler(String r,int m,int n){
super(r,m);noofwheel=n;
}void display(){
System.out.println("Two wheeler tvs");super.display();System.out.println("No. of wheel : " +noofwheel);
}}
class Threewheeler extends Vehicle{
int noofleaf;Threewheeler(String r,int m,int n){
super(r,m);noofleaf=n;
}void display(){
System.out.println("Three wheeler auto");
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super.display();System.out.println("No. of leaf:" +noofleaf);
}}
class Fourwheeler extends Vehicle{
int noofleaf;Fourwheeler(String r,int m,int n){
super(r,m);noofleaf=n;
}void display(){
System.out.println("Four wheeler car");super.display();System.out.println("No. of leaf:" +noofleaf);
}}
public class Vehicledemo{
public static void main(String arg[]){
Twowheeler t1;Threewheeler th1;Fourwheeler f1;t1=new Twowheeler("TN74 12345", 1,2);th1=new Threewheeler("TN74 54321", 4,3);f1=new Fourwheeler("TN34 45677",5,4);t1.display();th1.display();f1.display();
}}
21
OUTPUT:
RESULT:
Thus the program to design vehicle class hierarchy and to demonstrate polymorphism was executed and the output was verified successfully.
22
EX: NO. 6 Random Generation of objects
DATE:
AIM:
. To design classes namely Currency, Rupee, and Dollar. To write a program that randomly generates Rupee and Dollar objects and writes them into a file using object serialization. To write another program to read that file, and to convert to Rupee if it reads a Dollar, while leave the value as it is if it reads a Rupee.
ALGORITHM:
Step 1: Start the programs.Step 2: Define a class Currency as an abstract class with abstract methods.Step 3: Define the classes Rupee and Dollar as subclasses of Currency.Step 4: Define the abstract methods of the super class accordingly in each subclass.Step 5: The dollar value is converted to equivalent rupee value within a method of Dollar class.Step 6: Define a class StoreCurrency that randomly generates objects of Rupee and Dollar classes.Step 7: These objects are written into a file named currency using object serialization.Step 8: Define a class ReadCurrency that reads the objects from the file currency, and displays them.Step 9: Stop the programs.
23
PROGRAM:
Currency.java
import java.io.Serializable;public abstract class Currency implements Serializable {
protected static final Double DOLLAR_RUPEE_EXCHAGERATE = 44.445D; public Currency(Double money) {
super();this.money = money;
}protected Double money;public abstract Double getValue ();public abstract String getPrintableValue();
}
Rupee.java
public class Rupee extends Currency {
public Rupee(Double amount) {
super(amount);}public Double getValue() {
return this.money;}public String getPrintableValue() {
String strValue = "Object Name : Rupee \nINR : Rs " + getValue() + "\n------------------\n";
return strValue;}
}
Dollar.java
public class Dollar extends Currency {
public Dollar(Double money) {
super(money);}
24
public Double getValue() {
return (this.money * DOLLAR_RUPEE_EXCHAGERATE);}public String getPrintableValue() {
String strValue = "Object Name : Dollar \nUSD : $" + this.money + " \nINR : Rs" + getValue() + "\n------------------\n";
return strValue;}
}
StoreCurrency.java
import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectOutputStream;import java.util.Random;public class StoreCurrency {
public static void main(String[] args) throws FileNotFoundException,IOException
{Currency currency = null;ObjectOutputStream out = new ObjectOutputStream(new
FileOutputStream(new File("currency.dat")));Random random = new Random();for (int i = 0; i < 10; i++) {
int decide = random.nextInt();Double value = (random.nextDouble() *10);if ( (decide%2)==0 )
currency = new Rupee(value);else
currency = new Dollar(value);out.writeObject(currency);
}out.writeObject(null);out.close();
}}
25
ReadCurrency.java
import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.ObjectInputStream;public class ReadCurrency {
public static void main(String[] args) throws IOException, ClassNotFoundException
{Currency currency = null;ObjectInputStream in = new ObjectInputStream(new FileInputStream(new
File("currency.dat")));while ((currency = (Currency) in.readObject()) != null) {
System.out.println(currency.getPrintableValue());}in.close();
}}
26
OUTPUT:
RESULT:
Thus the program to generate objects randomly and to write them into a file using object serialization was executed. The file was read and the required rupee-dollar conversions were performed and the output was verified successfully.
27
EXP: No. 7 Calculator in Java
DATE:
AIM:
To design a calculator using event-driven programming paradigm of Java.
ALGORITHM:
Step 1: Start the program.Step 2: Create a frame for the calculator and include the swing components such as buttons and text field as required in it.Step 3: Layouts such as Border Layout and Grid Layout are used to align the components as per the requirements of the calculator.Step 4: Redefine the actionPerformed() method in the ActionListener interface to perform the appropriate operations when the buttons are pressed.Step 5: Provide mechanisms to handle the Number Format exceptions that may occur.Step 6: Stop the program.
28
PROGRAM:
import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.event.*;class Calculator extends JFrame {
private static final Font BIGGER_FONT = new Font("monspaced", Font.PLAIN, 20);
private JTextField _displayField; private boolean _startNumber = true; private String _previousOp ="="; private CalcLogic _logic = new CalcLogic(); public static void main(String[] args) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());} catch (Exception unused) {}Calculator window = new Calculator();window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);window.setVisible(true);
}public Calculator() {
_displayField = new JTextField("0", 12);_displayField.setHorizontalAlignment(JTextField.RIGHT);_displayField.setFont(BIGGER_FONT);JButton clearButton = new JButton("Clear");clearButton.setFont(BIGGER_FONT);clearButton.addActionListener(new ClearListener());ActionListener numListener = new NumListener();String buttonOrder = "789456123 0 ";JPanel buttonPanel = new JPanel();buttonPanel.setLayout(new GridLayout(5, 3, 2, 2));for (int i = 0; i < buttonOrder.length(); i++) {
String keyTop = buttonOrder.substring(i, i+1);JButton b = new JButton(keyTop);if (keyTop.equals(" ")) {
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b.setEnabled(false);}else {
b.addActionListener(numListener);b.setFont(BIGGER_FONT);
}buttonPanel.add(b);
}ActionListener opListener = new OpListener();JPanel opPanel = new JPanel();opPanel.setLayout(new GridLayout(5, 1, 2, 2));String[] opOrder = {"+", "-", "*", "/", "="};for (int i = 0; i < opOrder.length; i++) {
JButton b = new JButton(opOrder[i]);b.addActionListener(opListener);b.setFont(BIGGER_FONT);opPanel.add(b);
}JPanel clearPanel = new JPanel();clearPanel.setLayout(new FlowLayout());clearPanel.add(clearButton);JPanel content = new JPanel();content.setLayout(new BorderLayout(5, 5));content.add(_displayField,BorderLayout.NORTH );content.add(buttonPanel ,BorderLayout.CENTER);content.add(opPanel ,BorderLayout.EAST );content.add(clearPanel ,BorderLayout.SOUTH );content.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));this.setContentPane(content);this.pack();this.setTitle("Calculator");this.setResizable(false);
}private void actionClear() {
_startNumber = true; _displayField.setText("0");_previousOp = "=";_logic.setTotal("0");
}class OpListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
30
if (_startNumber) {
actionClear();_displayField.setText("ERROR - No operator");
} else {
_startNumber = true; try {
String displayText = _displayField.getText();if (_previousOp.equals("="))
_logic.setTotal(displayText);else if (_previousOp.equals("+"))
_logic.add(displayText);else if (_previousOp.equals("-"))
_logic.subtract(displayText);else if (_previousOp.equals("*"))
_logic.multiply(displayText);else if (_previousOp.equals("/"))
_logic.divide(displayText);_displayField.setText("" + _logic.getTotalString());
} catch (NumberFormatException ex) {
actionClear();_displayField.setText("Error");
}_previousOp = e.getActionCommand();
}}
}class NumListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
String digit = e.getActionCommand(); if (_startNumber) {
_displayField.setText(digit);_startNumber = false;
} else {
_displayField.setText(_displayField.getText() + digit);}
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}}class ClearListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
actionClear();}
}}class CalcLogic {
private int _currentTotal; public CalcLogic() {
_currentTotal = 0;}public String getTotalString() {
return "" + _currentTotal;}public void setTotal(String n) {
_currentTotal = convertToNumber(n);}public void add(String n) {
_currentTotal += convertToNumber(n);}public void subtract(String n) {
_currentTotal -= convertToNumber(n);}public void multiply(String n) {
_currentTotal *= convertToNumber(n);}public void divide(String n) {
_currentTotal /= convertToNumber(n); }
private int convertToNumber(String n) {
return Integer.parseInt(n); }}
32
OUTPUT:
RESULT:
Thus the program to design a calculator was executed and the output was verified successfully.
33
EXP: NO. 8 Multithreading in Java
DATE:
AIM:
To write a program in Java that prints all the prime numbers in the Fibonacci series below 10000 using multithreading.
ALGORITHM:
Step 1: Start the program.Step 2: Create a thread called Prime Thread that stores all the prime numbers below 10000.Step 3: Create another thread called Fibonacci Thread that stores the elements of the Fibonacci series below 10000.Step 4: Prime Thread and Fibonacci Thread are assigned a higher priority than the main thread of the program.Step 5: The main thread reads the values stored by both the threads, checks for the common elements and prints them.Step 6: Stop the program.
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PROGRAM:
interface maxlimit{
public static final int MAX_LIMIT=10000;}class prime extends Thread implements maxlimit{
int num[]=new int[MAX_LIMIT];prime(String n){
super(n);for(int i=0;i<MAX_LIMIT;i++)
num[i]=-1;}public void run(){
int k=0,flag;for(int i=2;i<=MAX_LIMIT;i++){
flag=0;for(int j=2;j<i;j++){
if(i%j==0){
flag=1;break;
}}if(flag==0){
num[k]=i;k++;
}}
}}class fibonacci extends Thread implements maxlimit{
int num[]=new int[MAX_LIMIT];fibonacci(String n){
super(n);for(int i=0;i<MAX_LIMIT;i++)
num[i]=-1;}
35
public void run(){
int f1=-1,f2=1,f3=0,k=0;while(f3<=MAX_LIMIT){
f3=f1+f2;num[k]=f3;k++;f1=f2;f2=f3;
}}
}class primefibi{
public static void main(String arg[]){
prime p=new prime("Prime Thread");fibonacci f=new fibonacci("Fibonacci Thread");p.setPriority(9);f.setPriority(9);p.start();f.start();System.out.println("Prime numbers in fibonacci series");for(int i=0;p.num[i]!=-1;i++){
for(int j=0;f.num[j]!=-1;j++){
if(p.num[i]==f.num[j]){
System.out.println(p.num[i]);break;
}}
}}
}
36
OUTPUT:
RESULT:
Thus the program to print the prime numbers in the Fibonacci series using multithreading was executed and the output was verified successfully.
37
EXP: NO. 9 Simple OPAC system for library
DATE:
AIM:
To develop a simple OPAC system for library using event-driven and concurrent programming paradigms of Java. JDBC is used to connect to a back-end database.
ALGORITHM:
Step 1: Start the program.Step 2: Design the front end for the library system.Step 3: Connect the front end with the database at the backend using JDBC.Step 4: Design the front end such that it accepts the inputs from the user and inserts the records into the database.Step 5: Display the contents of the database at the front end.Step 6: Suspend the established connections.Step 7: Stop the program.
38
PROGRAM:
Datas.java
import java.sql.*;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Datas extends JFrame implements ActionListener{
JTextField id;JTextField name;JButton next;JButton addnew;JPanel p;static ResultSet res;static Connection conn;static Statement stat;public Datas(){
super("Our Application");Container c = getContentPane();c.setLayout(new GridLayout(5,1));id = new JTextField(20);name = new JTextField(20);next = new JButton("Next BOOK");p = new JPanel();c.add(new JLabel("ISBN",JLabel.CENTER));c.add(id);c.add(new JLabel("Book Name",JLabel.CENTER));c.add(name);c.add(p);p.add(next);next.addActionListener(this);pack();setVisible(true);addWindowListener(new WIN());
}public static void main(String args[]){
Datas d = new Datas();try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");conn = DriverManager.getConnection("jdbc:odbc:custo"); stat = conn.createStatement();
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res = stat.executeQuery("Select * from stu"); res.next();
}catch(Exception e) {
System.out.println("Error" +e);}d.showRecord(res);
}public void actionPerformed(ActionEvent e){
if(e.getSource() == next) {
try {
res.next();}catch(Exception ee){}showRecord(res);
}}public void showRecord(ResultSet res){
try {
id.setText(res.getString(2));name.setText(res.getString(3));
}catch(Exception e){}
}class WIN extends WindowAdapter{
public void windowClosing(WindowEvent w) {
JOptionPane jop = new JOptionPane();
jop.showMessageDialog(null,"Database","Thanks",JOptionPane.QUESTION_MESSAGE);
}}
}
40
Prog1.java
import java.sql.*;import java.sql.DriverManager.*;class Ja{
String bookid,bookname;int booksno;Connection con;Statement stmt;ResultSet rs;Ja(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");con=DriverManager.getConnection("jdbc:odbc:co");
}catch(Exception e){
System.out.println("connection error");}
}void myput(){
try{
stmt=con.createStatement();rs=stmt.executeQuery("SELECT * FROM opac");while(rs.next()){
booksno=rs.getInt(1);bookid=rs.getString(2);bookname=rs.getString(3);System.out.println("\n"+ booksno+"\t"+bookid+"\
t"+bookname);}rs.close();stmt.close();con.close();
}catch(SQLException e){
System.out.println("sql error");}
41
}}class prog1{
public static void main(String arg[]){
Ja j=new Ja();j.myput();
}}OUTPUT:
RESULT:
Thus the program to design a simple OPAC system for library was executed and the output was verified successfully.
42
43
EXP: NO. 10 Multithreaded Echo Server and Client
DATE:
AIM:
To develop a multithreaded echo server and a corresponding client.
ALGORITHM:
Step 1: Start the program.Step 2: Create a Socket at the Server side.Step 3: Design the server such that it responds to each client using a separate thread.Step 4: The server receives the data sent by the client and echoes those data.Step 5: Provide the necessary exception handling mechanisms at the server.Step 6: Create a Socket at the client side.Step 7: Get the host name from the user.Step 8: Establish a connection between the server and the client.Step 9: Transmit the data from the client side to the server.Step 10: Provide the necessary exception handling mechanisms at the client.Step 11: Stop the program.
44
PROGRAM:
EchoServer.java
import java.net.*; import java.io.*; public class EchoServer {
ServerSocket m_ServerSocket; public EchoServer() {
try {
m_ServerSocket = new ServerSocket(12111); } catch(IOException ioe) {
System.out.println("Could not create server socket at 12111. Quitting.");
System.exit(-1); } System.out.println("Listening for clients....."); int id = 0; while(true) {
try {
Socket clientSocket = m_ServerSocket.accept(); ClientServiceThread cliThread = new
ClientServiceThread(clientSocket, id++); cliThread.start();
} catch(IOException ioe) {
System.out.println("Exception encountered on accept. Ignoring. Stack Trace :");
ioe.printStackTrace(); }
} } public static void main (String[] args) {
new EchoServer(); } class ClientServiceThread extends Thread {
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Socket m_clientSocket; int m_clientID = -1; boolean m_bRunThread = true; ClientServiceThread(Socket s, int clientID) {
m_clientSocket = s; m_clientID = clientID;
} public void run() {
BufferedReader in = null; PrintWriter out = null; System.out.println("Accepted Client : ID - " + m_clientID + " :
Address - " + m_clientSocket.getInetAddress().getHostName()); try {
in = new BufferedReader(new InputStreamReader(m_clientSocket.getInputStream()));
out = new PrintWriter(new OutputStreamWriter(m_clientSocket.getOutputStream()));
while(m_bRunThread) {
String clientCommand = in.readLine(); System.out.println("Client Says :" +
clientCommand); if(clientCommand.equalsIgnoreCase("quit")) {
m_bRunThread = false; System.out.print("Stopping client thread for
client : " + m_clientID); } else {
out.println(clientCommand); out.flush();
} }
} catch(Exception e) {
e.printStackTrace(); } finally {
try {
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in.close(); out.close(); m_clientSocket.close(); System.out.println("...Stopped");
} catch(IOException ioe) {
ioe.printStackTrace(); }
} }
} }
EchoClient.java
import java.net.*; import java.io.*; public class EchoClient {
public static void main(String[] args) {
if(args.length == 0) {
System.out.println("Usage : EchoClient <serverName>"); return;
} Socket s = null; try {
s = new Socket(args[0], 12111); } catch(UnknownHostException uhe) {
System.out.println("Unknown Host :" + args[0]); s = null;
} catch(IOException ioe) {
System.out.println("Cant connect to server at 12111. Make sure it is running.");
s = null; } if(s == null)
System.exit(-1);
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BufferedReader in = null; PrintWriter out = null; try {
in = new BufferedReader(new InputStreamReader(s.getInputStream()));
out = new PrintWriter(new OutputStreamWriter(s.getOutputStream()));
out.println("Hello"); out.flush(); System.out.println("Server Says : " + in.readLine()); out.println("This"); out.flush(); System.out.println("Server Says : " + in.readLine()); out.println("is"); out.flush(); System.out.println("Server Says : " + in.readLine()); out.println("a"); out.flush(); System.out.println("Server Says : " + in.readLine()); out.println("Test"); out.flush(); System.out.println("Server Says : " + in.readLine()); out.println("Quit"); out.flush();
} catch(IOException ioe) {
System.out.println("Exception during communication. Server probably closed connection.");
} finally {
try {
out.close(); in.close(); s.close();
} catch(Exception e) {
e.printStackTrace(); }
} }
}
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OUTPUT:
RESULT:
Thus the program to develop a multithreaded echo server and client was executed and the output was verified successfully.
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