java
TRANSCRIPT
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
1
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
2
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
3
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY
HYDERABAD
II Year B.Tech.CSE II-Sem T P C
0 3 2
(07A41291) OBJECT ORIENTED PROGRAMMING LAB
OBJECTIVES:
• To make the student learn a object oriented way of solving problems.
• To teach the student to write programs in java to solve problems.
RECOMMENDED SYSTEMS/SOFTWARE REQUIREMENTS:
• Intel based desktop PC with minimum of 166MHZ or faster processor with atleast 64MB RAM and 100MB free disk space.
• JDK kit. Recommended. WEEK 1:
a) Write a java program that prints all real solutions to the quadratic equation ax2 + bx +c =0. Read in a, b ,c and use the quadratic formula. If the discriminant b2 – 4ac is negative display a message stating that there are no real solutions.
b) The Fibonacci sequence is defined by the following rule: The fist two values in the sequence are 1 and 1. Every subsequent value is the Sum of the two values preceding it. Write a java program that uses both recursive and non recursive functions to print the nth value in the Fibonacci Sequence.
WEEK 2:
a) Write a java program that prompts the user for an integer and then prints Out all prime numbers up to that integer.
b) Write a java program to multiply two given matrices. c) Write a java program that reads a line of integer, and then displays
each integer, and the sum of all the integers(use string tokenizer class of java.util)
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
4
WEEK 3:
a) Write a java program that checks whether a given string is a palindrome or Not. Ex: MADAM is a palindrome.
b) Write a java program for sorting a given list of names in ascending order.
c) Write a java program to make frequency count of words in a given text.
WEEK 4:
a) Write a java program that reads a file name from the user , then displays The information about whether the file exists, whether the file readable, Whether the file is writable, the type of file and the length of the file in bytes.
b) Write a java program that reads a file and displays the file on the screen, With a line number before each line.
c) Write a java program that displays the number of characters, lines and Words in a text file.
WEEK 5:
a) Write a java program that: i) Implements stack ADT. ii) Converts infix expression into postfix from iii) Evaluates the postfix expression
WEEK 6:
a) Develop an applet that displays a simple message. b) Develop an applet that receives an integer in one text field, and
computers its factorial Value and returns it in another text field, when the button named “Compute” is clicked.
WEEK 7:
Write a java program that works as a simple calculator. Use a grid layout to arrange buttons for the digits and for the +,-,*,% operations. Add a text field to display the result. Week 8 a) Write a java program for handling mouse events.
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
5
Week 9:
a) Write a java program that creates three threads. First thread displays “Good Morning” every one second, the second thread displays “Hello” every two seconds and the third thread displays “Welcome” every three seconds. b) Write a java program that correctly implements producer consumer problem using the concpect of inter thread communicatin
week 10:
A)write a program that creates a user interface to perform integer divisions. The user enters two numbers in the textfields, num1 and mum2. The division of num1 and num2 is display in the Result field when the divide button is clicked. If num1 and num2 were not an integer, the program would throw a numberformatexception. If num2 were zero the program would throw an arithmeticexception . week 11:
write a program that implements a simple client/server application
Week 12:
a)write a java program that simulates a traffic light. The progam lets the user to select one of three lights. Red yellow, or green. When radio button is selected the light is turned on, and only one light can be on at time. No light is on when program starts b)Write a java program that allow the user to draw lines, rectangles and arcs.
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
6
INDEX
PROGRAM PAGE NO.
1.Write a java program that prints all real solutions to the quadratic
equation ax2 + bx +c =0. Read in a, b ,c and use the quadratic formula. If the discriminant b2 – 4ac is negative display a message stating that there are no real
solutions. 8 2.The Fibonacci sequence is defined by the following rule:The fist two values in the
sequence are 1 and 1. Every subsequent value is the Sum of the two values preceding it. Write a java program that uses both recursive and non recursive functions to print the nth value in the Fibonacci
Sequence. 9,10
3.Write a java program that prompts the user for an integer and then prints Out all
prime numbers up to that integer. 11 4.Write a java program to multiply two given matrices. 12 5.Write a java program that reads a line of integer, and then displays each integer, and
the sum of all the integers(use string tokenizer class of java.util) 13
6.Write a java program that checks whether a given string is a palindrome or
Not. Ex: MADAM is a palindrome. 14 7.Write a java program for sorting a given list of names in ascending order. 14
8.Write a java program to make frequency count of words in a given text. 15 9.Write a java program that reads a file name from the user , then displays The
information about whether the file exists, whether the file readable,Whether the file is writable, the type of file and the length of the file in bytes. 16
10.Write a java program that reads a file and displays the file on the screen, With a
line number before each line. 16 11.Write a java program that displays the number of characters, lines and Words in a
text file. 17
12.Write a java program that:
Implements stack ADT. 18
converts infix expression into postfix from 21
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
7
13.Develop an applet that displays a simple message. 24
14.Develop an applet that receives an integer in one text field, and computers its factorial Value and returns it in another text field, when the button named “Compute”
is clicked. 25
15. Write a java program that works as a simple calculator. Use a grid layout to arrange buttons for the digits and for the +,-,*,% operations. Add a text field to
display the result. 26 16.Write a java program for handling mouse events. 30 17. Write a java program that creates three threads. First thread displays “Good
Morning” every one second, the second thread displays “Hello” every two seconds and the third thread displays “Welcome” every three seconds. 32
18.Write a java program that correctly implements producer consumer problem
using the concpect of inter thread communication 33 19.write a program that creates a user interface to perform integer divisions. The
user enters two numbers in the textfields, num1 and mum2. The division of num1 and num2 is display in the Result field when the divide button is clicked. If num1 and num2 were not an integer, the program would throw a numberformatexception.
If num2 were zero the program would throw an arithmetic exception. 35 .20.write a program that implements a simple client/server application. 36
21.write a java program that simulates a traffic light. The progam lets the user to select one of three lights. Red yellow, or green. When radio button is selected the light is turned on, and only one light can be on at time. No light is on when program
starts 37 22.Write a java program that allow the user to draw lines, rectangles and arcs.
38
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
8
Aim :Write a Java Program that prints all real solutions to the
quadratic equation ax2+bx+C=0. Read in a, b, c and use the
quadratic formula. If the discriminate b2 4ac is negative, display a
message stating that there are no real solutions.
class quadratic { public static void main (String ar[]) { int a,b,c; a = Integer.parse Int (ar[0]); b = Integer.parse Int (ar[1]); c = Integer.parse Int (ar[2]); int d = ((b*b) – (4*a*c)); double r1 = (-b+Math.Sqrt(d))/(2xa); double r2 = (-b – Math, Sqrt (d))/(2xa); if (d<0) { System.out.println (“these are no real solutions”); } else { System.out.println (r1 + “/n” + r2 ); } } } Input : Java quad 1-5 6
Output: 3.0 2.0
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
9
Aim : write a Java program of Fibonacci series:
Recursive: class a { int fib(int n) { if (n==0) return 0; else if (n==1) return 1; else return (fib (n-1) + fib (n-2)); } } class fib { public static void main (string ar[]) { a a1= new a(); int i=0,c,n; n= Integer.parse Int (ar []); System.out.println(“fib series”+n+”is”); do { c=a1.fib(i); if (c<=n) System.out.println(C); i=t; } while (c<=n) } } Output : Java fib 10
0
1
1
2
3
5
8
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
10
//Aim : WAP for Non-Recursive Fibonacci series:
class ab { public static void main (String ar[]) { int f=1, s=1,t=0; int n = Integer.parse Int (ar[0]); System.out.println(f=””+s); for (int i=3.; i<=n, i++) { t= f+s; System.out.println(t); f=s; s = t; } } } Output : Java ab 10
1 1 2 3 5 8 13 21 34 55
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
11
Aim : Write a Java program that prompts the user for an integer and
then prints all prime number upto that integer.
Import java.io.*; class prime { public static void main (String ar[]) throws Exception { BufferedReaderbr=newBufferedReader(new inputreamReader(System.in); Int n=Integer.pareseInt(br.readLine(); For(int i=1;i<=n;i++) int c=0; for (int j=1; j<=is j++) { if (i%j==0) c++; } if (c==2) System.out.println(i); } } Output: Java prime 20
2 3 5 7 11 13 17 19
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
12
Aim : Write a Java program to multiply to given matrices.
class matrix { public static void main(String ar[]) { int i,j,k; int a[][]={{1,4,5}, {3,2,1}, {0,6,7}}; int b[][]={{1,2,3}, {7,6,0}, {5,4,1}}; int c[][]=new int [3][3]; for (i=0; i<=2; i++) { for (j=0; j<=2; j++) { c[i][j]=0; for (k=0;k<=2; k++) { c[i][j]=c[i][j]+a[i][k]*b[k][j]; } } } System.out.println (“multiplication is”); for (i=0; i<a.length; i++) { for (j=0; /<b.length;i++) { System.out.print(c[i][j]+””); } System.out.println(); } } } Output : Java matrix
54 46 8
22 22 10
22 64 7
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
13
Aim : WAP that reads a line of integers and then displays each
integers and the sum of all the integers (use string tokenizer class)
import java.io.*; import java.util.*; class ab { public static void main (string ar[]) throcos exception { InputstreamReader isr= new InputStreamReader (system.in); BufferReader br=new BufferReader (isr); String S=br.readLine(); int sum=0; StringTokenizer st=new stringTokenizer (s,””); while (st.hasMoreTokens ()); { String sl= st.nextToken(); int n= integer.parseInt (Sl); System.out.println(n); sum=sum+n; } System.out.println(s); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
14
Aim : wap to check a string is palindrome or not
class Poly { public static void main(String ar[]) { String s=ar[0]; String Buffer str =new String Buffer(s); str.reverse(); String s1=str.tostring(); if(s1.Equals(s)); System.out.println(“palindrome”); else System.out.println(“not palindrome”); } } Aim : To sort a given list of names in ascending order
class ab { public static void main(String ar[]) { String s[]={ab”,”ca”,”abc”}; String t; int n=s.length; for(int i=0;i<=n-1;i++) { for (int j=i+1;j<n;j++) { int k=s[i].compareto(s[i]); if (k>=0) { t=s[i]; s[i]=s[j]; s[j]=t; } } } for(i=0;i<=n;i++) System.out.println(s[i]); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
15
Aim : wap to make frequency count of words in a given text
import java.util.*; class sdemo { public static void main(String ar[]) { String str=” this is java”; int c=0; StringTokenizer st=new StringTokenizer(str,” “); while(st.hasMoreTokens()) { String s=st.nextToken()) c++; } System.out.println(c); }}
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
16
Aim : Wap that reads filename from user then displays information
about whether the file file exits whether the file is readable, whether
the file is writable. The type of file and length of file in bytes
import java.io.*; class ab { public static void main (String ar[]); { File f1 = new File(“a.java”); System.out.println(f1.exists()); System.out.println(f1.canRead()); System.out.println(f1.canwrite()); System.out.println(f1.isfile()); System.out.println(f1.isDirectory()); System.out.println(f1.length()); } } Aim : Wap that reads a file and display the file on the screen with a
line number before each line
import java.io.*; class files { public static void main(String ar[]) throws Exception { int i=1; DataInputstream br=new DataInputStream(System.in); System.out.println(“enter file name”); String s=br.readlnne(); FileInputStream f=new FileInputStream(s); Byte c; System.out.println(i+” “); c=(byte)f.read(); do { System.out.println((char) c); if(c==”\n”) { i++; System.out.println(“\n”+i+” “); }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
17
c=(byte)f..read(); } while(c>0) f.close(); } } Aim: Wap that display the number of characters, lines & words in
text file
import java.io.*; class files { public static void main(String ar[]) { int ch=0,w=0.l=0; DataInputStrean br=new DataInputStream(system.in); System.out.println(“enter filename”); String s=br.readline(); FileInputStream f= new FileInputStream(s); Byte c; c=(byte) f.read(); do { if(c==’ ‘) w++; if(c==”\n”) { w++; if(c==”\n”) { w++; l++; } else ch++; c=(byte)f.read(); } while(c>0) f.close; System.out.println(“no of char”+ch); System.out.println(“no. of words”+w); System.out.println(“no of lines”+l); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
18
Aim : write a java program that implements stack ADT
import java.io.*; class S { final int max=20; int top; int s[]=new int[max]; S() { top=-1; } void push(int x) { if(top==max-1) { system.out.println(“stack full”); return; } s[++top]=x; } int pop() { if(top==-1) { System.out.println(“stack empty”); return 0; } int t=s[top--]; return t; } void display() { if(top==-1) System.out.println(“stack empty”); else { for(int i=0;i<=top;i++) { System.out.println(“\t”+s[i]); } } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
19
} Class Stackadt { public static void main(String args[])throws Exception { DataInputStream br=new DataInputStream(System.in); ss1=new s(); do { System.out.println(“1.push \n 2.pop \n 3.display \n 4.exit”); int n=0,n1=0; System.out.println(“enter ur choice”); n=integer.parseInt(br.readLine()); switch(n) { case 1: system.out.println(“enter no of elements topush”); n1=integer.parseInt(br.readLine()); System.out.println(“enter elements”); for(int i=0;i<n;i++) s1.push(Integer.parseInt(br.readLine()); break; case 2: System.out.println(“enter the no of elements to pop”); int n2=Integer.parseInt(br.readLine()); System.out.println(“poped elements”); for(int i=0;i<n;i++) System.out.println(“\t”+s1.pop()); break; case 3: System.out.println(“elements of stack are”); s1.display(); break; case 4: system.exit(0); break; }} while(true) } } o/p:
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
20
java stkadt 1.push 2.pop 3.display 4.exit enter ur choice 1 enter no of elements to push 3 enter the elements 2 3 4 enter ur choice 2 enter the elements to pop 2 poped elements 4 enter ur choice 4
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
21
Aim:Write a java program that converts infix expression into postfix
form
import java.io.*; class Stk; { final static int max=50; int top=-1; char s[]=new char[max]; char s2[]=new char[max]; string 1=” “; string t=” “; void push(char x) { if(top==max-1) { System.out.println(“stack is full”); return; top++; s2[top]=x; } char pop(); { if(top==-1) { System.out.println(“stack is empty”); return 0; } char t=s2[top]; top=-1; return t; } int pri(char c) { if(c==’$’) return 3; if(c==’*’||c==’/’||c==’%’) return 1; else return 0; }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
22
void infix() { char opr; for(int i=0;i<s.length;i++) { if(s[i]==’ ‘) continue; if(character.is letter.digits(s[]i])) k+=s[i]; if(s[i]==’(‘) push(s[i]); if(s[i]==’*’||s[i]==’+’||s[i]==’-‘||s[i]==’/’||s[i]==’5’||s[i]==’$’) { if(top!=1) { opr=pop(); while(pri(opr)>=pri(s[i])) { k+=opr; opr=pop(); } push(opr); push(s[i]); } else push(s[i]); } if(s[i]==’)’); { opr=pop(); while(opr!=’(‘) { k+=opr; opr=pop(); } } } while(top!=-1) { opr=pop(); k+=opr; } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
23
void display() { System.out.println(“postfix notation is /t”+t); } } class Inpost { public static void main(String args[])throws Exception { stk d=new stk(); DataInputStream br=new DataInputStream(System.in); System.out.println(“enter infix notation”); d.a=br.readLine(); for(int i=0;i<d.a.length();i++) d.s[i]=d.a.charAt(i); d.infix(); d.display(); } } o/p: java inpost enter infix expression a+b-c*d/e stack is empty postfix notation is ab+cd*e/-
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
24
Aim: write an applet that displays a simple message
import java.awt.*; import java.applet.*; /*<applet code=”colapp.class” width=200 height=200> </applet>*/ public class colapp extends applet { public void paint(Graphics g) { g.setColor(color,red) g.drawLine(10,10,100,10); g.setColor(color.blue); g.drawLine(100,10,100,100); f.setColor(color.green); g.drawLine(10,10,100,100); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
25
Aim :develop an applet that receives an integer in one text field, and
compute its factorial value and returns it in another text field, when
the button named compute is clicked
import java.awt.*; import java.awt.event.*; import java.applet.*; /*<applet code="fact.class" width=300 height=300></applet>*/ public class fact extends Applet implements ActionListener { int n; TextField t1, t2; Label l1; Button b; public void init() { l1=new Label("enter n value",Label.LEFT); t1=new TextField(20); b=new Button("compute"); t2=new TextField(20); add(l1); add(t1); add(b); add(t2); b.addActionListener(this); } public void actionPerformed(ActionEvent ae) { String s1=t1.getText(); int f=1; int n=Integer.parseInt(s1); for(int i=1;i<=n;i++) f=f*i; String s="fact="+f; t2.setText(s); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
26
Aim: wap that works as a simple calculator
import java.io.*; import java.lang.*; import java.awt.*; import java.awt.event.*; class exal extends Frame implements ActionListener { String Temp=” ”; GridBagLayout gb; TextField t; Button b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16; GridBagconstraints gc; exal() { setSize(150,150); gb=new GridBagLayout(); gc=new GridBagconstraints(); t=new TextField(8); b0=new Button(“0”); b0=new Button(“0”); b0=new Button(“0”); b1=new Button(“1”); b2=new Button(“2”); b3=new Button(“3”); b4=new Button(“4”); b5=new Button(“5”); b6=new Button(“6”); b7=new Button(“7”); b8=new Button(“8”); b9=new Button(“9”); b10=new Button(“=”); b11=new Button(“clr”); b12=new Button(“+”); b13=new Button(“-”); b14=new Button(“*”); b15=new Button(“/”); b16=new Button(“%”); b1.addActionListener(this); b2.addActionListener(this); b3.addActionListener(this); b4.addActionListener(this); b5.addActionListener(this); b6.addActionListener(this);
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
27
b7.addActionListener(this); b8.addActionListener(this); b9.addActionListener(this); b10.addActionListener(this); b11.addActionListener(this); b12.addActionListener(this); b13.addActionListener(this); b14.addActionListener(this); b15.addActionListener(this); b16.addActionListener(this); t.addActionListener(this); setLayout(gb); set(0,0,4,1,t,gb,gc); set(0,2,1,1,b1,gb,gc); set(1,2,1,1,b2,gb,gc); set(2,2,1,1,b3,gb,gc); set(0,3,1,1,b4,gb,gc); set(1,3,1,1,b7,gb,gc); set(2,3,1,1,b8,gb,gc); set(0,4,1,1,b9,gb,gc); set(1,4,1,1,b10,gb,gc); set(2,4,1,1,b11,gb,gc); set(1,5,1,1,b12,gb,gc); set(2,5,1,1,b1,gb,gc); set(0,5,1,1,b13,gb,gc); set(3,2,1,1,b14,gb,gc); set(3,3,1,1,b15,gb,gc); set(3,4,1,1,b16,gb,gc); set(3,5,1,1,b17,gb,gc); set(9,0,1,1,b1,gb,gc); show(); } void set (int x, int y, int w, int h, Button b, GridBagLayout g1, GridBagConstraints g2) { g2.gridx=x; g2.gridy=y; g2.gridWidth=w; g2.gridheight=h; g1.setConstraints(b,g2); add(b); }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
28
void set(int x, int y, int w, int h, TextField t, GridBagLayout g1, GridBagConstraints g2) { g2.gridx=x; g2.gridy=y; g2.gridWidth=w; g2.gridHeight=h; g1.setConstraints(t,g2); add(t); } public void actionPerformed(ActionEvent ae) { String s=ae.getActionCommand(); If(s==”=”) { temp=” “+(k.getText()); for(int i=0;i<temp.lenth();i++) { if(temp.charAt(i)==’+’) { String num1=temp.subString(0,i); String num2=temp.subString(i+1,temp.length()); int a=Integer.parseInt(num1); int b=Integer.parseInt(num2); int c=a+b; t.setText(“ “+c); } if(temp.charAt(i)==’-’) { String num1=temp.subString(0,i); String num2=temp.subString(i+1,temp.length()); int a=Integer.parseInt(num1); int b=Integer.parseInt(num2); int c=a-b; t.setText(“ “+c); } if(temp.charAt(i)==’*’) { String num1=temp.subString(0,i); String num2=temp.subString(i+1,temp.length()); int a=Integer.parseInt(num1); int b=Integer.parseInt(num2); int c=a*b;
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
29
t.setText(“ “+c); } if(temp.charAt(i)==’/’) { String num1=temp.subString(0,i); String num2=temp.subString(i+1,temp.length()); int a=Integer.parseInt(num1); int b=Integer.parseInt(num2); int c=a/b; t.setText(“ “+c); } if(temp.charAt(i)==’%’) { String num1=temp.subString(0,i); String num2=temp.subString(i+1,temp.length()); int a=Integer.parseInt(num1); int b=Integer.parseInt(num2); int c=a%b; t.setText(“ “+c); } } } else if(s==”clr”) { t.setText(“ “); temp=” ”; } else { temp+=s; t.setText(“ “+temp); } } } class calc { Public static void main(String ar[]) { exal e=new exal(); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
30
Aim :wap for handling mouse events
import java.awt.*; import java.awt.event.*; import java.applet.*; /*<applet code=”mouseevents.class” width=300 height=300></applet>*/ public class mouseevents extends Applet implements MouseListener, MouseMotionListener { String msg=” “; int mx=0;my=0; public void init() { add.MouseListener(this); add.MouseMotionListener(this); } public void mouseClicked(MouseEvent me) { mx=0; my=10; msg=”mouse clicked”; repaint(); } public void mouseEntered(MouseEvent me) { mx=0; my=10; msg=”mouse entered”; reapaint(); } public void mouseExited(MouseEvent me) { mx=0; my=10; msg=”mouse exited”; reapaint(); } public void mousePressed(MouseEvent me) { mx=me.getX(); my=me.getY();
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
31
msg=”mouse down”; reapaint(); } public void mouseReleased(MouseEvent me) { mx=me.getX(); my=me.getY(); msg=”*”; showStatus(“dragging mouse at”+me.getX()+”,”+me.getY()); reapaint(); } public void mouseMoved(MouseEvent me) { showStatus(“moving mouse at”+me.getX()+”,”+me.getY()); } Public void paint(Graphics g) { g.drawString(msg,mx,my); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
32
Aim :wap that creates three theads. First thread displays “good
morning” every one second. The second thread display” hello” every
two seconds and third thread displays “welcome” every three seconds
class mt implants Runnable { Thread t; String s; int t; mt(String ss, int tt) { t=new Thread(this, ss); s=ss; t=tt t.start(); public void run() { for(;;) { System.out.println(s); try { Thread.sleep(t); } Catch(Exception e) { } } } class ab { public static void main(String ar[]) { mt t1=new mt(“good morning”,1000); mt t2=new mt(“hello”,2000); mt t1=new mt(“welcome”,3000); }}
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
33
Aim :Wap that correctly implements producer customer problem
using the concept of interthread communication
class Q { int n; Boolean valueset=false; Synchronized int get() { if(! valueset) try { wait(); } catch(InterruptedException e) { System.out.println(“interrupted Exeception caught”); } System.out.println(“GDk:”+n); valueSet=false; notify(); return n; } Synchronized void put(int n) { if (valueset) try { wait(); } Catch(InterruptedException e) { System.out.println(“interrupted Exception Caught”); } this.n=n; valueset=true; System.out.println(“put:”+n); notify(); } } class producer implements Ryunnable { Q q;
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
34
Producer (Q q) { this.q=q; new thread(this,”producer”).strat(); } public void run() { int i=0; while(true) { q.put(i++); } } } class consumer implements Runnable { Q q; Consumer(q q) { this.q=q; new Thread(this,”consumer”).strat(); } public void run() { while(true) { q.get(); } } } class pcfixed { public Static void main(String ar[]) { Q q=new Q(); new producer(q); new consumer(q); System.out.println(“press ctrl c to stop”); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
35
Aim : write a program that creates a user interface to perform
integer divisions. The user enters two numbers in the textfields, num1
and num2. the division of num1 and num2 is displayed in the result
field when the divide button is clicked. If num1 or num2 were not an
integer, the program would throw a NumberFormatException. If
num2 were zero, the program would trow an ArithmeticException.
Display the exception in message dialog box
import java.awt.*; import java.awt.event.*; import java.applet.*; /*<applet code="ap.class" width=300 height=300></applet>*/ public class ap extends Applet implements ActionListener { Button b1; TextField t1, t2,r ; Label l1,l2; String s,e; public void init() { l1=new Label("enter x"); l2=new Label("enter y"); t1=new TextField(10); t2=new TextField(10); r=new TextField(10); b1=new Button("division"); add(l1); add(t1); add(l2); add(t2); add(b1); add(r); b1.addActionListener(this); } public void actionPerformed(ActionEvent ae) { int x=Integer.parseInt(t1.getText()); int y=Integer.parseInt(t2.getText()); s="division="+(x/y); r.setText(s); }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
36
Aim: wap program implements simple Client/Server program
Import javax.servlet.*’ Import javax.servlet.http.*; Import java.io.*; Public class GetPostServlet extends HttpServlet { Public void doGet(HttpServletRequest req, HttpServletResponse res) Throws ServletException, IOException { Res.setContentType(“text/html”); Printwriter out=res.getwrite(); Out.println(“<html><head>”); Out.println(“<title>handling get request</title>”); Out.println(“<body><h2>get request received</h2>”); Out.println(“<h3>type ur name and press send</h3>”); Out.println(“<form method=\”post\>”); Out.println(“<input type=\”text”\name=\”user\”>”); Out.pritnln(“<input type=\”submit\” value=\”send\”/>; Out.println(“</form>”); Out.println(“</body></html>”)’ } Public void doPost(httpservletrequest req, httpservletresponse res)throws servletexecption, ioexception { Res.setcontentType(“text/html”); Printwriter out=res.getwriter(); String user = req.getParameter(“user”); Out.println(“<html><head>”); Out.println(“<title>handling post request</title>”); Out.println(“<body><h2>post request received</h2>”); Out.println(“hello”<em>mr.”+user+”</em>”); Out.println(“</body></html>”); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
37
Aim: Write a java program that simulates a traffic light. The
program lets the user select one of three lights. Red,yello,or green.
When a radio button is selected the light is turned on, and only one
light can be on at a time. No light is on when the program starts.
import java.awt.*; import java.awt.event.*; import java.applet.*; /*<applet code="abc.class" width=300 height=300></applet>*/ public class abc extends Applet implements ItemListener { CheckBox c1,c2,c3; CheckBoxGroup cbg=new CheckBoxGroup(); public void init() { c1=new CheckBox(“red”,cbg,true); c2=new CheckBox(“yellow”,cbg,true); c3=new CheckBox(“green”,cbg,true); add(c1); add(c2); add(c3); c1.addItemListener(this); c2.addItemListener(this); c3.addItemListener(this); } public void itemStateChanged(ItemEvent ie) { String s=(cbg.getSelectCheckBox()).getLable()); if(s.equals(“red”)) setBackGround(Color.red); elseif(s.equals(“yellow”)) setBackGround(Color.yellow); elseif(s.equals(“green”)) setBackGround(Color.green); } }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
38
Aim: wap that allows the user to draw lines, rectangles and ovals
import java.awt.*; import java.awt.event.*; import java.applet.*; /*<applet code=”draw.class” width=1500 height=1500></applet>*/ public class draw extends Applet implements ItemListener, MouseListener,MouseMotionListener { Choice ch; String msg=” “; int x1=0;x2=0;y1=0;y2=0; public void init() { ch=new choice(); ch.add(“select anyone”); ch.add(“Line); ch.add(“Rectangle”); ch.add(“oval”); add(ch); setBackground(color.yellow); setForeground(color.red); addMouseListener(this); ch.additemListener(this); addMouseMotionListener(this); } public void itemStatechanged(item Event ie) { repaint(); } public void mouseclicked(Mouse Event me) { repaint(); } public void mouseEntered(MouseEvent me) { repaint() } public void mousePressed(MouseEvent me) { x1=me.getx(); y1=me.gety(); repaint(); }
JYOTHISHMATHI INSTITUTE OF TECHNOLOGY & SCIENCE
Prepared by k.Aparanji Gurdeep kour
39
public void MouseReleased(Mouse Event me) { x2=me.getx(); y2=me.getY(); repaint(); } public void mouseDragged(mouse Event me) { repaint(); } public void mouseMoved(mouseEvent me) { showStatus(“morning at”+me.getx()+”, “+me.gety()); } public void paint(Graphics g) { msg=ch.getselectedItem(); if(msg.Equals(“line”) { g.drawLine(x1,y1,x2,y2); } if(msg.Equals(“rectangle”) { g.fillRect(x1,y1,x2-x1,y2-y1); } if(msg.Equals(“oval”)); { g.filloval(x1,y1,x-x1,y2-y1); } } }