CS2309 JAVA LAB MANUAL

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  • 1. MADHA ENGINEERING COLLEGE DEPARTMENT OF CSE REGULATION-2008 CS2306 – JAVA LAB LAB MANUAL 1
  • 2. SYLLABUS 1. Develop Rational number class in Java. Use Java Doc comments for documentation. Your implementation should use efficient representation for a rational number, i.e. (500 / 1000) should be represented as (½). 2. Develop Date class in Java similar to the one available in java.util package. Use Java Doc comments. 3. Implement Lisp-like list in Java. Write basic operations such as 'car', 'cdr', and 'cons'. If L is a list [3, 0, 2, 5], L.car () returns 3, while L.cdr() returns [0,2,5]. 4. Design a Java interface for ADT Stack. Develop two different classes that implement this interface, one using array and the other using linked- list. Provide necessary exception handling in both the implementations. 5. Design a Vehicle class hierarchy in Java. Write a test program to demonstrate polymorphism. 6. Design classes for Currency, Rupee, and Dollar. Write a program that randomly generates Rupee and Dollar objects and write them into a file using object serialization. Write another program to read that file, convert to Rupee if it reads a Dollar, and while leave the value as it is if it reads a Rupee. 7. Design a scientific calculator using event-driven programming paradigm of Java. 8. 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. 9. Develop a simple OPAC system for library using even-driven and concurrent programming paradigms of Java. Use JDBC to connect to a back-end database. 10.Develop multi-threaded echo server and a corresponding GUI client in Java. 11.[Mini-Project] Develop a programmer's editor in Java that supports syntax-highlighting, compilation support, debugging support, etc. 2
  • 3. 1. IMPLEMENTATION OF RATIONAL NUMBER Develop Rational number class in Java. Use JavaDoc comments for documentation. Your implementation should use efficient representation for a rational number, i.e. (500 / 1000) should be represented as (½). ALGORITHM: STEP 1: Get two inputs from the user through command line arguments. STEP 2: Store the numerator to variable a and denominator to variable b. STEP 3: If both a and b are either positive or negative, set the flag as 0. STEP 4: If either a or b is negative, set flag as 1. STEP 5: Compare the values of a and b and assign the lowest value to c. STEP 6: Set the for loop for i=2. STEP 7: If both a and b values are divisible by i, then perform (i) a=a/i; (ii) b=b/i; (ii) i=1; STEP 8: Repeat the loop if the value of i is less than c. Break the loop if the condition fails. STEP 9: If flag is 1, display the result as negative number; else display it as positive number. RationalClass.java import java.util.*; /** *@author Sreekandan.K */ public class RationalClass { /** The Numerator part of Rational */ private int numerator; 3
  • 4. /** The Denominator part of Rational */ private int denominator; /** create and initialize a new Rational object */ public RationalClass(int numerator,int denominator) { if(denominator==0) { throw new RuntimeException("Denominator is zero"); } int g=gcd(numerator,denominator); if(g==1) { System.out.println("No Common Divisor for Numerator and Denominator"); this.numerator=numerator; this.denominator=denominator; } else { this.numerator=numerator/g; this.denominator=denominator/g; } } /** return string representation */ public String display() { return numerator+"/"+denominator; } /** @param m @param n @return Greatest common divisor for m and n */ private static int gcd(int n,int d) { 4
  • 5. if(d==0) return n; else return gcd(d,n%d); } 2. IMPLEMENTATION OF DATE SERVER Develop Date class in Java similar to the one available in java.util package. Use Java Doc comments. ALGORITHM: STEP 1: Create a package which consists of constructors with the following arguments: i) Default ii)Taking 3 arguments year, day and month iii)Taking 5 arguments year, day, month, hours and minutes iv)Taking 6 arguments year, day, month, hour, minutes and seconds STEP 2: Get the year, month, date, hours, minutes, seconds using the getYear(), getMonth(), getDate(), getHours(), getMinutes(), getSeconds() methods. STEP 3: Set all these details using set methods. STEP 4: After()-the after() method returns true if the current date comes after the specified date else it returns false STEP 5: Before()-the before()method returns true if the current date comes before the specified date else it returns false STEP 6: Compare()-the compare() method compares the current date with the specified date and returns 0 if it is equal,if after it returns 1 and if before it returns -1. DateFormatDemo.java import java.text.*; import java.util.*; /** *Class DateFormatDemo formats the date and time by using java.text package * */ public class DateFormatDemo { public static void main(String args[]) { /** 5
  • 6. * @see java.util package */ Date date=new Date(); /** * @see java.text package */ DateFormat df; System.out.println("Current Date and Time - Available in java.util Package:"); System.out.println("-------------------------------------------------------"); System.out.println(date); System.out.println(); System.out.println("Formatted Date - Using DateFormat Class from java.text Package:"); System.out.println("---------------------------------------------------------------"); df=DateFormat.getDateInstance(DateFormat.DEFAULT); System.out.println("Default Date Format:"+df.format(date)); df=DateFormat.getDateInstance(DateFormat.SHORT); System.out.println("Date In Short Format:"+df.format(date)); df=DateFormat.getDateInstance(DateFormat.MEDIUM); System.out.println("Date In Medium Format:"+df.format(date)); df=DateFormat.getDateInstance(DateFormat.LONG); System.out.println("Date In Long Format:"+df.format(date)); df=DateFormat.getDateInstance(DateFormat.FULL); System.out.println("Date In Full Format:"+df.format(date)); System.out.println(); System.out.println("Formatted Time - Using DateFormat Class from java.text Package:"); System.out.println("---------------------------------------------------------------"); df=DateFormat.getTimeInstance(DateFormat.DEFAULT); System.out.println("Default Time Format:"+df.format(date)); df=DateFormat.getTimeInstance(DateFormat.SHORT); System.out.println("Time In Short Format:"+df.format(date)); df=DateFormat.getTimeInstance(DateFormat.MEDIUM); System.out.println("Time In Medium Format:"+df.format(date)); df=DateFormat.getTimeInstance(DateFormat.LONG); System.out.println("Time In Long Format:"+df.format(date)); df=DateFormat.getTimeInstance(DateFormat.FULL); System.out.println("Time In Full Format:"+df.format(date)); System.out.println(); System.out.println("Formatted Date and Time - Using SimpleDateFormat Class from java.text Package:"); System.out.println("------------------------------------------------------------------------------" ); /** * @see java.text package */ SimpleDateFormat sdf; sdf=new SimpleDateFormat("dd MMM yyyy hh:mm:sss:S E w D zzz"); 6
  • 7. System.out.println(sdf.format(date)); } } 7
  • 8. 3. IMPLEMENTATION OF LISP-LIKE LIST Implement Lisp-like list in Java. Write basic operations such as 'car', 'cdr', and 'cons'. If L is a list [3, 0, 2, 5], L.car() returns 3, while L.cdr() returns [0,2,5]. ALGORITHM STEP 1: Create a node of a list having data part and link part. STEP 2: Create a menu having the following choices : insert, car, cdr, adjoin and display. STEP 3: Read the choice from the user and call the respective m ethods. STEP 4: Create another class which implements the same interface to implement the concept of stack through linked list. INSERT STEP 1: Create an object of node and append to the list. CAR STEP 1: Return the first node data. CDR STEP 1: Return all the node (data part) in the list except the first node. ADJOIN STEP 1: Check if the node to be inserted is already present in the list, if not present append to the list. LispOperation.java import java.util.*; /** * */ class Lisp { public Vector car(Vector v) { Vector elt=new Vector(); elt.addElement(v.elementAt(0)); return elt; } public Vector cdr(Vector v) { Vector elt=new Vector(); for(int i=1;i<v.size();i++) elt.addElement(v.elementAt(i)); return elt; } public Vector cons(int x, Vector v) { v.insertElementAt(x,0); return v; } } 8
  • 9. 4. IMPLEMENTATION OF STACK Design a Java interface for ADT Stack. Develop two different classes that implement this interface, one using array and the other using linked-list. Provide necessary exception handling in both the implementations. ALGORITHM STEP 1: Create an interface which consists of three methods namely PUSH, POP and DISPLAY STEP 2: Create a class which implements the above interface to implement the concept of stack through Array STEP 3: Define all the methods of the interface to push any element, to pop the top element and to display the elements present in the stack. STEP 4: Create another class which implements the same interface to implement the concept of stack through linked list. STEP 5: Repeat STEP 4 for the above said class also. STEP 6: In the main class, get the choice from the user to choose whether array implementation or linked list implementation of the stack. STEP 7: Call the methods appropriately according to the choices made by the user in the previous step. STEP 8: Repeat step 6 and step 7 until the user stops his/her execution StackADT.java import java.io.*; import java.util.*; interface stackInterface { int n=50; public void pop(); public void push(); public void display(); } class stack implements stackInterface { int arr[]=new int[n]; int top=-1; Scanner in=new Scanner(System.in); public void push() { try { System.out.println("Enter The Element of Stack"); int elt=in.nextInt(); arr[++top]=elt; } catch (Exception e) { 9
  • 10. System.out.println("e"); } } public void pop() { int pop=arr[top]; top--; System.out.println("Popped Element Is:"+pop); } 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+" "+arr[i]; System.out.println("Stack Elements Are:"+str); } } } /** * */ 10
  • 11. 5. IMPLEMENTATION OF VEHICLE CLASS USING POLYMORPHISM Design a Vehicle class hierarchy in Java. Write a test program to demonstrate Polymorphism. ALGORITHM STEP 1: Create an abstract class named vehicle with abstract method Display and a concrete method Input. STEP 2: Define the input method by prompting the user to enter the values for name, owner, type, number, engine capacity, seating capacity for the vehicle; all the inputs taken in the form string. STEP 3: Extend three classes namely Air, Water and Land from the base class. STEP 4: Define the method display under the class Air by displaying all the entered values. STEP 5: Repeat step 4 for the class Water. STEP 6: Extend the input method for the class Land by taking in the value of wheeling capacity for the vehicle in the form of string. STEP 7: In the main method create a reference for the abstract class and create a switch case to perform operations on the opted class. STEP 8: Under each class create a switch case to either enter the data or to display the transport report. STEP 9: Repeat the main menu on the user's choice. STEP 10: Create array of objects under each class and call the methods by assigning the values of the created objects to the reference object, to show polymorphism. VehicleDemo.java import java.io.*; class Vehicle { String regno; int model; Vehicle(String r, int m) { regno=r; model=m; } void display() { System.out.println("Registration Number:"+regno); System.out.println("Model Number:"+model); } } class Twowheeler extends Vehicle { 11
  • 12. int wheel; Twowheeler(String r,int m,int n) { super(r,m); wheel=n; } void display() { System.out.println("Vehicle : Two Wheeler"); System.out.println("====================="); super.display(); System.out.println("Number of Wheels:"+wheel+"n"); } } class Threewheeler extends Vehicle { int leaf; Threewheeler(String r,int m,int n) { super(r,m); leaf=n; } void display() { System.out.println("Vehicle : Three Wheeler"); System.out.println("======================="); super.display(); System.out.println("Number of Leaf:"+leaf+"n"); } } class Fourwheeler extends Vehicle { int leaf; Fourwheeler(String r,int m,int n) { super(r,m); leaf=n; } void display() { System.out.println("Vehicle : Four Wheeler"); System.out.println("======================"); super.display(); System.out.println("Number of Leaf:"+leaf); } } /** **/ 12
  • 13. 6. IMPLEMENTATION OF CURRENCY CONVERTER Design classes for Currency, Rupee, and Dollar. Write a program that randomly generates Rupee and Dollar objects and write them into a file using object serialization. Write another program to read that file, convert to Rupee if it reads a Dollar, while leave the value as it is if it reads a Rupee. ALGORITHM FOR PROGRAM 1: STEP 1: Create a class named currency that implements the serializable interface and also it is the base class for rupee and dollar classes. STEP 2: Create an object for ObjectOutputStream to open a file in write mode using FileOutputStream. STEP 3: Read the user choice to enter rupee or dollar amount. STEP 4: Generate random numbers as the value of rupee or dollar. STEP 5: If choice is rupee then, append "Rs" to the value generated, else if choice is dollar append "$" to the value generated. STEP 6: Display the appended String and also write it into the file opened using the writeObject() method. STEP 7: Close the file. ALGORITHM FOR PROGRAM 2: STEP 1: Create a class named currency that implements the serializable interface and also it is the base class for rupee and dollar classes. STEP 2: Create an object for ObjectInputStream to open the file created in program1 in read mode using FileInputStream. STEP 3: If the file does not exist or if it is empty show exceptions. STEP 4: While the End of file is not reached, do the following... (i) If the value read is a dollar convert into rupee and print to the user otherwise print the rupee as such. STEP 5: End the program. writeObj.java import java.io.*; import java.util.*; abstract class Currency implements Serializable { protected double money; public abstract double getValue(); public abstract String printObj(); public Currency(double money) { this.money=money; } } class Dollar extends Currency 13
  • 14. { public Dollar(int money) { super(money); } public double getValue() { return this.money*51; } public String printObj() { String object="Object Name : DollarnUSD : $"+this.money+"nINR : Rs"+getValue()+"n"; return object; } } class Rupee extends Currency { public Rupee(int amount) { super(amount); } public double getValue() { return this.money; } public String printObj() { String object="Object Name : Rupee nINR : Rs "+getValue()+"n"; return object; } } /** * */ 14
  • 15. 7. IMPLEMENTATION OF CALCULATOR Develop a scientific calculator using even-driven programming paradigm of Java. ALGORITHM: STEP 1: Create a panel consisting of Buttons for various scientific operations. STEP 2: Create Button actions. STEP 3: Place the panel onto a frame. STEP 4: Associate each Button click with the corresponding actionlistener. SimpleCalculator.java import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.lang.*; /** * */ public class SimpleCalculator { public static void main(String[] args) { CalcFrame cf=new CalcFrame(); cf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); cf.setVisible(true); } } class CalcFrame extends JFrame { public CalcFrame() { setTitle("CALCULATOR"); CalcPanel panel=new CalcPanel(); add(panel); pack(); } } class CalcPanel extends JPanel { JButton display; JPanel panel; double result; String lastcmd; boolean start; public CalcPanel() { 15
  • 16. setLayout(new BorderLayout()); result=0; lastcmd="="; start=true; display=new JButton("0"); display.setEnabled(false); add(display,BorderLayout.NORTH); ActionListener insert=new InsertAction(); ActionListener cmd=new CommandAction(); panel=new JPanel(); panel.setLayout(new GridLayout(5,4)); addButton("1",insert); addButton("2",insert); addButton("3",insert); addButton("/",cmd); addButton("4",insert); addButton("5",insert); addButton("6",insert); addButton("*",cmd); addButton("7",insert); addButton("8",insert); addButton("9",insert); addButton("-",cmd); addButton("0",insert); addButton(".",insert); addButton("pow",cmd); addButton("+",cmd); addButton("sin",insert); addButton("cos",insert); addButton("tan",insert); addButton("=",cmd); add(panel, BorderLayout.CENTER); } private void addButton(String label,ActionListener listener) { JButton button=new JButton(label); button.addActionListener(listener); panel.add(button); } private class InsertAction implements ActionListener { public void actionPerformed(ActionEvent ae) { String input=ae.getActionCommand(); if(start==true) { display.setText(""); start=false; 16
  • 17. } if(input.equals("sin")) { Double angle=Double.parseDouble(display.getText())*2.0*Math.PI/360.0; display.setText(""+Math.sin(angle)); } else if(input.equals("cos")) { Double angle=Double.parseDouble(display.getText())*2.0*Math.PI/360.0; display.setText(""+Math.cos(angle)); } else if(input.equals("tan")) { Double angle=Double.parseDouble(display.getText())*2.0*Math.PI/360.0; display.setText(""+Math.tan(angle)); } else display.setText(display.getText()+input); } } private class CommandAction implements ActionListener { public void actionPerformed(ActionEvent ae) { String command=ae.getActionCommand(); if(start==true) { if(command.equals("-")) { display.setText(command); start=false; } else lastcmd=command; } else { calc(Double.parseDouble(display.getText())); lastcmd=command; start=true; } } } public void calc(double x) { if(lastcmd.equals("+")) result=result+x; else if(lastcmd.equals("-")) 17
  • 18. result=result-x; else if(lastcmd.equals("*")) result=result*x; else if(lastcmd.equals("/")) result=result/x; else if(lastcmd.equals("=")) result=x; else if(lastcmd.equals("pow")) { double powval=1.0; for(double i=0.0;i<x;i++) powval=powval*result; result=powval; } display.setText(""+ result); } } 18
  • 19. 8. IMPLEMENTATION OF FIBONACCI SERIES USING FRAMES 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: CreateThread1 which generates prime numbers below 100,000 and store in pipe1. STEP 2: Create Thread2 which generates Fibonacci numbers below 100,000 and store in pipe 2. STEP 3: Write a main program which does the following: (i) Call the two threads created in step1 and step2. (ii) Read the data from pipe1 and pipe 2 and print the numbers common to both. MultiThreadDemo.java import java.util.*; import java.io.*; class Fibonacci extends Thread { private PipedWriter out=new PipedWriter(); public PipedWriter getPipedWriter() { return out; } public void run() { Thread t=Thread.currentThread(); t.setName("Fibonacci"); System.out.println(t.getName()+" Thread started..."); int fibo=0,fibo1=0,fibo2=1; while(true) { try { fibo=fibo1+fibo2; if(fibo>100000) { out.close(); break; } out.write(fibo); sleep(1000); 19
  • 20. } catch(Exception e) { System.out.println("Exception:"+e); } fibo1=fibo2; fibo2=fibo; } System.out.println(t.getName()+" Thread exiting..."); } } class Prime extends Thread { private PipedWriter out1=new PipedWriter(); public PipedWriter getPipedWriter() { return out1; } public void run() { Thread t=Thread.currentThread(); t.setName("Prime"); System.out.println(t.getName() +" Thread Started..."); int prime=1; while(true) { try { if(prime>100000) { out1.close(); break; } if(isPrime(prime)) out1.write(prime); prime++; sleep(0); } catch(Exception e) { System.out.println(t.getName()+" Thread exiting..."); System.exit(0); } } } public boolean isPrime(int n) { int m=(int)Math.round(Math.sqrt(n)); 20
  • 21. if(n==1||n==2) return true; for(int i=2;i<=m;i++) if(n%i==0) return false; return true; } } /** * */ 21
  • 22. 8. IMPLEMENTATION OF FIBONACCI SERIES USING FRAMES Develop a simple OPAC system for library using event-driven and concurrent programming paradigms of Java. Use JDBC to connect to a back-end database. ALGORITHM: STEP 1: Create a Master Database1(Book Details) having the following fields: BookNo.Book Name, Author, No. of pages, Name of Publisher, Cost. STEP 2: Create a Master Database2(User Details) having the following fields : UserID, Department STEP 3: Create a Transaction Database having the following fields: UserID, Book No., Date of Renewal / Date of Return, Fine STEP 4: Create a panel consisting of buttons ADD, UPDATE, DELETE. Associate these button actions with listeners(with Master Database 1) STEP 5: Create a panel consisting of buttons ADD, UPDATE, DELETE. Associate these button actions with listeners(with Master Database 2) STEP 6: Create another panel consisting of buttons UserID, BookID, Return/Renewal,Fine. STEP 7: Associate these buttons with listeners(with Transaction Database). OpacSystem.java import java.sql.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.table.*; /** * */ public class OpacSystem implements ActionListener { JRadioButton author=new JRadioButton("Search By Author"); JRadioButton book=new JRadioButton("Search by Book"); JTextField txt=new JTextField(30); JLabel label=new JLabel("Enter Search Key"); JButton search=new JButton("SEARCH"); JFrame frame=new JFrame(); JTable table; DefaultTableModel model; String query="select*from opacTab"; public OpacSystem() { frame.setTitle("OPAC SYSTEM"); frame.setSize(800,500); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); 22
  • 23. JPanel p1=new JPanel(); p1.setLayout(new FlowLayout()); p1.add(label); p1.add(txt); ButtonGroup bg=new ButtonGroup(); bg.add(author); bg.add(book); JPanel p2=new JPanel(); p2.setLayout(new FlowLayout()); p2.add(author); p2.add(book); p2.add(search); search.addActionListener(this); JPanel p3=new JPanel(); p3.setLayout(new BorderLayout()); p3.add(p1,BorderLayout.NORTH); p3.add(p2,BorderLayout.CENTER); frame.add(p3,BorderLayout.NORTH); addTable(query); frame.setVisible(true); } public void addTable(String str) { try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); Connection con=DriverManager.getConnection("jdbc:odbc:opacDS"); Statement stmt=con.createStatement(); ResultSet rs=stmt.executeQuery(str); ResultSetMetaData rsmd=rs.getMetaData(); int cols=rsmd.getColumnCount(); model=new DefaultTableModel(1,cols); table=new JTable(model); String[] tabledata=new String[cols]; int i=0; while(i<cols) { tabledata[i]=rsmd.getColumnName(i+1); i++; } model.addRow(tabledata); while(rs.next()) { for(i=0;i<cols;i++) tabledata[i]=rs.getObject(i+1).toString(); model.addRow(tabledata); } frame.add(table,BorderLayout.CENTER); 23
  • 24. con.close(); } catch(Exception e) { System.out.println("Exception:"+e); } } public void actionPerformed(ActionEvent ae) { if(author.isSelected()) query="select*from opacTab where AUTHOR like '"+txt.getText()+"%'"; if(book.isSelected()) query="select*from opacTab where BOOK like '"+txt.getText()+"%'"; while(model.getRowCount()>0) model.removeRow(0); frame.remove(table); addTable(query); } 24
  • 25. 10. IMPLEMENTATION OF MULTITHREADED ECHO SERVER & ECHO CLIENT Develop multi-threaded echo server and a corresponding GUI client in Java. ALGORITHM FOR SERVER: STEP 1: Establish the connection of socket. STEP 2: Assign the local Protocol address to the socket. STEP 3: Move the socket from closed to listener state and provide maximum no. of Connections. STEP 4: Create a new socket connection using client address. STEP 5: Read the data from the socket. STEP 6: Write the data into socket. STEP 7: Close the socket. EchoServer.java import java.io.*; import java.net.*; /** * */ public class EchoServer { public static void main(String [] args) { System.out.println("Server Started...."); try { ServerSocket ss=new ServerSocket(300); while(true) { Socket s= ss.accept(); Thread t = new ThreadedServer(s); t.start(); } } catch(Exception e) { System.out.println("Error: " + e); } } } class ThreadedServer extends Thread { Socket soc; public ThreadedServer(Socket soc) 25
  • 26. { this.soc=soc; } public void run() { try { BufferedReader in=new BufferedReader(new InputStreamReader(soc.getInputStream())); PrintWriter out=new PrintWriter(soc.getOutputStream()); String str=in.readLine(); System.out.println("Message From Client:"+str); out.flush(); out.println("Message To Client:"+str); out.flush(); } catch(Exception e) { System.out.println("Exception:"+e); } } } ALGORITHM FOR CLIENT: STEP 1: Open the socket. STEP 2: Get the host name and port number from client. STEP 3: Write a request to the buffer that contain the request number as a byte to the output stream. STEP 4: Get the message from the user. STEP 5: Write to the socket. STEP 6: Set the write operation for success. STEP 7: Read the contents from the socket / Buffer. STEP 8: Close the socket. EchoClient.java import java.net.*; import java.io.*; import javax.swing.*; import java.awt.*; import java.awt.event.*; /** * */ class EchoClient extends JFrame { 26
  • 27. JTextArea ta; JTextField msg; JPanel panel; JScrollPane scroll; JButton b1=new JButton("Close"); JButton b2=new JButton("Send"); JLabel l1=new JLabel("Echo Client GUI"); Container c; EchoClient() { c=getContentPane(); setSize(300,470); setTitle("GUI Client"); panel=new JPanel(); msg=new JTextField(20); panel.setLayout(new FlowLayout(FlowLayout.CENTER)); ta=new JTextArea(20,20); scroll=new JScrollPane(ta); panel.add(l1); panel.add(ta); panel.add(msg); panel.add(b2); panel.add(b1); c.add(panel); b2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { try { Socket s=new Socket("localhost",300); BufferedReader in=new BufferedReader(new InputStreamReader(s.getInputStream())); PrintWriter out=new PrintWriter(new OutputStreamWriter(s.getOutputStream())); out.println(msg.getText()); out.flush(); String temp =ta.getText(); if(temp.equalsIgnoreCase("quit")) { System.exit(0); } msg.setText(""); ta.append("n"+in.readLine()); } catch (IOException e) { ta.setText("Exception:"+e); 27
  • 28. } } }); b1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.exit(0); } }); } public static void main(String args[]) { EchoClient frame=new EchoClient(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } } 28
  • 29. 11. MINI PROJECT Develop a programmer's editor in Java that supports syntax high lighting, compilation support, debugging support, etc. ALGORITHM: STEP 1: Create a panel consisting of menu bar containing File, Edit, Compile and Debug. STEP 2: Add submenus for each of the menu. File – New, Open, Save, Quit. Edit – Cut, Copy, Paste. Compile – Compile, Link Debug – Inspect, Call Stack, Watches, BreakPoints. STEP 3: Associate these event sources with Listeners. 29