4. Contents
1. Introduction to Java
1.1. History of java
1.2. Features of java
1.3. OO principles of java
1.4. Java vs. c and c++
2. Installing Java
2.1. Java development tools
2.2. Downloading java
2.3. Installing java and setting environment variables
2.4. Download eclipse
2.5. Installing eclipse
3. First Java Program
3.1. Running a java program
3.2. Hello world program
4. Data Types
4.1. What are data types?
4.2. Integer
4.3. Float
4.4. Character
4.5. Boolean
5. Variables
5.1. What are variables?
5.2. Types of variables
5.3. Creating variables
6. Strings
6.1. What are strings?
6.2. Operations on strings
7. Arrays
7.1. What are arrays?
7.2. Creating an array
7.3. Initializing an array
7.4. Displaying an array
8. Operators
8.1. What are operators?
5. 8.2. Types of operators
9. Control Statements
9.1. What are control statements?
9.2. Types of control statements
10.Classes
10.1. What are classes?
10.2. Advantages of classes
10.3. Creating a class
11.Objects
11.1. What are Objects
11.2. Steps to create an object
12.Construtors
12.1. What are constructors?
12.2. Rules for creating constructors
12.3. Types of constructors
13.Methods
13.1. What are methods?
13.2. Structure of method definition and method call
14.Inheritance
14.1. What is inheritance?
14.2. Types of inheritance
14.3. Inheriting a class
14.4. Example
15.Exception Handling
15.1. What are exceptions?
15.2. Keywords(try, throw, catch)
15.3. Example
16.Interfaces and packages
16.1. What are interfaces?
16.2. Example
16.3. What are packages?
16.4. Creating a package
16.5. Using a package
16.6. Some common java packages
17.Multithreading
17.1. What is multithreading?
17.2. Thread class
17.3. Runnable interface
6. 17.4. Synchronization
18.File I/O
18.1. What are streams?
18.2. Byte streams
18.3. Character streams
19.Serialization
19.1. What is serialization?
19.2. Serializable interface
20.Collections Framework
20.1. Collection interface
20.2. Other interfaces
21.Lambda Expressions
21.1. What is functional interface?
21.2. What is lambda expression?
22.Generics
22.1. What are generics?
22.2. Generic classes
22.3. Generic methods
23.Event Handling
23.1. Introduction to Event Hanlding
23.2. Different types of events
23.3. Example
24.Applets
24.1. What are applets?
24.2. Applets life cycle methods
24.3. Example
25.AWT(Abstract Windows Toolkit)
25.1. What is AWT?
25.2. Container classes
25.3. Component classes
25.4. Frame class
26.Swing
26.1. What is swing?
26.2. Features of swing
26.3. Swing classes
26.4. Example
27.Servlets
27.1. Architecture of servlets
8. Preface
The idea of writing a book about Java Development in Hindi can be somewhat futile at times,
considering the pace at which Java continues to expand, morph and change. What started out
as a book project two years ago has now become a series of updates to the original work with
the page count nearly double the original project and that after making hard decisions about
what to leave out of the book to make sure it gets liked.
This update to Java in Hindi represents our latest effort to provide coverage on important
Java Development topics, namely the expansion into the Swing.
Like many things in life, the only constant is change, but by now we are somewhat
accustomed to the rapid-fire environment of Java Development. To the end, we have ensured
that all the programs work with eclipse as well as without eclipse.
The third edition is written by Vipin Kumar Sharma. Thank you for learning and collaborating
with us.
VIPIN KUMAR SHARMA
9. Acknowledgement
Writing a third edition of Java in Hindi feels somewhat like the old saying about weddings:
“Something old, something new…” The deadline for the third edition did not become any
easier as at last count there are still only 24 hours in the day. And as for something new it
seems as though Java’s pace of innovation is continuing to match its adoption rate by users
around the globe.
In particular, we’d like to acknowledge and thank everyone at www.besthinditutorials.com.
Firstly I would like to thank our EBook Designers and editors, who have been involved in
every aspect of now three editions of this project. I would also like to thank our publisher to
bring this masterpiece in EBook format.
10. About this book
Java in Hindi, Third Edition is a revision and update of the second edition published in 2013.
This third edition adds new content related to java 8. Like its predecessors, this book covers
important beginner topics such as “What is Java?” and installing and using the development
environment. We than advance to practical working examples of core programming topics
any developer will be happy to have at the ready on the reference shelf. The remaining
chapter’s present detailed example applications covering advanced topics, including AWT and
Swing.
Although you can read the book from start to finish, you can also consider it a few books in
one. If you are new to Java focus first on beginning chapters. With the foundation you can
work your way up to last chapter.
Who should read this book?
We wrote this book for professional programmers and hobbyists alike. Many of the concepts
can absorbed without specific Java language knowledge. If you have c, c++ or c# knowledge,
you will be able to follow the examples.
Prior eclipse experience is helpful, but not required. A number of good resources are available
on java and eclipse to augment the content of this book.
And lastly the person who is willing to learn java in his mother tongue Hindi should read this
book.
Road map
1. Basic – first 10 chapters contain basic information regarding java programming.
2. Intermediate – next 10 chapters are somewhat of intermediate level and necessary
java topics.
3. Advanced – remaining chapters covers some advanced topics of java language.
11. Chapter 1
Introduction
This chapter covers:
History of Java
Features of Java
OO Principles
Java vs. c and c++
History of java
Java एक general purpose object oriented programming Sun Micro-systems java
1991 U.S. Java क oak क change क क java क
Java James Gosling develop क Java क consumer electronics क TV, VCR
software क ए develop क
Java क important औ popular feature क java platform independent क java क
एक particular hardware operating system क ए Java ए program
क system execute क क Java क feature java क popular
12. Features of java
Java क features एक java programmer क ए क features
ए java क क popular features क क क
Compiled and interpreted
programming languages compiled interpreted क java
approaches क combine क औ एक two stage system java क program क
compiler क क byte code generate क Byte code machine instructions ए java
second stage byte code क interpret क क machine code generate क , directly
execute क क
Platform independent
Java क byte code platform independent क java program क compile क
byte code convert byte code क operating system क
JVM (Java Virtual Machine)
Java क program क run क क ए क operating system JVM install क
operating system क ए JVM क क एक क औ क उ
operating system क ए byte code क machine code convert क ए क एक operating
system क JVM generate क byte code क JVM run क क औ
JVM उ operating system क ए machine code generate क
ए machines क ए machine code generate क एक byte
code generate क क program byte code convert
Object oriented
Java एक true object oriented programming language Java almost क object Java
क information objects क store
13. Robust and secure
Java एक robust language Java क program environments
technologies क crash ए क क क Java programs क crash
reliable language
Java security JVM क provide क Machine code generate क JVM क
tests क क invalid combinations क detect क
Distributed
Java distributed applications ए क क Distributed applications applications
networks औ एक क task perform क Java RMI क through
network available applications interact क क
Simple and familiar
Java एक simple language Java क features c औ c++ ए ए Java क syntax c औ
c++ क क variable declarations, control statements औ method declarations
java क easy understand क java c औ c++ क क ए
programmers क familiar
Multi-threaded and interactive
Java एक multi-threaded language क java program एक क tasks complete क क
feature java क fast औ interactive
High performance
Java क performance impressive Java क speed क main reason byte code Java क
architecture design क क java run time over head क
Dynamic and Extensible
Java एक dynamic language Java run time क libraries, methods औ classes dynamic
linking क Java क technologies क क क
14. Ease of development
Java programs develop क easy Java क built libraries provide क
क क ए important classes programmer क overhead क
Programmer libraries क access क क software develop क क
Object oriented principles of java
क क java एक object oriented language Java object oriented
programming languages क object oriented principles क follow क principles
क क क
Encapsulation
Encapsulation क data hiding क Encapsulation private variables declare क औ
उ public methods क through access क क variables क क class क methods access
क क क class क variables क access क क क data क hide
क औ क
Encapsulation क एक औ data औ code क एक unit bind क औ access क
क क क variables औ methods एक unit bind Java 3 level क data
hiding provide क
public - क public class members क classes access क क
private - क private class members क क class access क क
protected - क क class क inherit क class क class members क access
क क
15. Inheritance
principle क through एक class क variables क class access क क क
क एक methods क क computer क memory औ
programmer क time Java multiple inheritance allow एक class एक
class क inherit क क क interfaces क through क
Polymorphism
Polymorphism क "एक औ क क " Polymorphism क through एक interface
situation एक according actions क क method overloading क
Abstraction
Abstraction java क important concept क क क
bike क क क उ उ क internal working क
Abstraction क same concept software क internal working क क
क interface provide क क interact क
Java development tools
Java software क built in development tools क development
tools क क क
JDK(Java Development Kit)
JDK एक environment क java program ए क क औ उ क execute
क क JDK JRE क java program क execution क ए responsible
JRE(Java Run-time Environment)
16. JRE क program क execution क ए responsible JRE क classes औ libraries क group
एक क program क execute क ए environment ए क
JRE क 2 क
1. Program main क
2. Program क execution start क
JVM (Java Virtual Machine)
क क क java program क compile क byte code convert
क byte code machine code convert क JVM एक environment
machine byte code क machine code convert क JRE क क क क
17. Chapter 2
Installing Java
This chapter covers:
Java development tools
Installing java and eclipse
Installing java
Java 2 क क एक command prompt version उ क क
क java औ क editor क क क औ
command prompt उ क क क क IDE उ क क एक
environment क उ क क क official
क NetBeans IDE क Eclipse उ क क
Java command prompt platform औ NetBeans IDE उ क क
http://www.oracle.com/technetwork/java/javase/downloads/index.html
19. Chapter 3
First Java Program
This chapter covers:
Running a java program
Hello world program
Running a java program
क क क क 2 क . java IDE क use क
notepad औ console उ क . क
console क क क क ए
1. Through IDE (Integrated Development Environment)
2. Through Console
Through IDE
IDE क क क क क औ क
क . IDE क Eclipse, NetBeans क . क क
IDE Java Compiler क execute क . क क एक IDE उ क .
20. Through Console
Console program क क steps ए ए .
1. Run cmd क औ command prompt ओ क
2. Command prompt ओ क क उ drive install औ क bin
folder क locate क
23. Hello world program
एक simple क क क
क lecturer board औ
क क copy क औ क ओ एक simple notepad
क औ उ क क java program क क How to
run a java program tutorial क एक message क
inverted commas (" ") क एक ए क HelloJava औ
main println क क क क क
क औ , ए description क क
public - public एक access modifier Access modifiers 3 क (public, private,
protected) औ क members क ए क क क क क tutorials
class - एक क ए क क क क important
concept क क Class क
24. HelloJava - क क क ए
static - keyword क method क क क क क ए क क
क क main क java run time environment program क execute
क क ए access क
main - एक क क execution उ
main
String args [] - string array command line arguments क ए क
क execute क argument क क
System.out.println () - system एक package , out एक , औ println एक ,
command prompt screen उ क क ए क
25. Chapter 4
Data Types
This chapter covers:
What are data types?
Integer
Float
Character
Boolean
Introduction to java data types
Data, data औ data. Computer क data data??. Data क
क available क क क उ उ क Data type क
क data औ क
क data क category क क ??. क data
operations perform क क operations(Addition, Subtraction, Multiplication
and Division) क perform क क क क perform क क
क variable ए क उ क क data store क define क
data type क Java data types क 4 categories define क
26. Integers
Integers complete number numbers fractional part ( औ उ क क
) include क क Integers क उ क size क according 4 categories define क
क
Type Explanation Example
Byte Byte क size 8 bit -127 क 128 क क क value
byte store क क
byte age = 40;
Short Short क size 16 bit Short -32,768 क 32,767
क क क value store क क
short salary =
25000;
Int Int क size 32 bit Int -2,147,483,648 क
2147483747 क क क store क क
int
population =2,00,000
Long Long क size 64 bit value store क
क
long worldpop =
8000000000
Floating point numbers
Floating point numbers numbers fractional part ( औ उ क क ) क
represent क क important mathematical calculation क numbers
क Floating point numbers क 2 categories define क क
Type Explanation Example
Float Float single precision value क represent क Float क size
32 bit Float 1.4e-045 क 3.4e+038 क क value
store क क Float क क एक value
represent क
float temp = 34.4;
27. Double Double double precision value क represent क Double क
size 64 bit Double 4.9e-324 क 1.8e+308 क क
value store क क Double क 7 value क
store क क
double pi = 3.1416;
Character
क एक क store क क ए character क Character क size 16 bit
Character क char keyword represent क
Example - char FavLang = 'c';
Boolean
Boolean data types क logical decision store क क ए क Boolean variables क 2
values true false
Example - boolean isFiveMoreThanOne = true;
28. Chapter 5
Variables
This chapter covers:
What are variables?
Types of variables
Creating variables
Introduction to java variables
क information क store क क ए variables क उ क औ उ information क
उ variable क value क information क क , क क क औ
उ क उ store क क ए क 2 variables क एक variable उ
क store क औ variable उ क उ store क
क variable क value changeable क value store क क
variables क value change क क constants क
Information क store क क variables क create क Variable ए क क ए
variable क variable क unique ए compiler error
generate क variable क क datatype define क
Data type information type क क क क information store क
क क store क क store क क store
29. क Variable क क क store क
data type क
Types of variables
Java variables क उ क scope क 2 types क
Local variables
क method क variable ए क उ variable क उ method क
उ method क variable क क उ variable क scope क variables
क scope क method क उ local variables क
Global variables
क क variable program क उ क method declare क
variables क program क starting declare क variables program क
क क variables program global variables क Global
variables क scope program
Creating variables in java
Java variables ए क क 2 stages क क क
Variable declaration
stage variable क औ क क values store क define क
Example - int personAge; // data type and variable name
Variable initialization
stage variable क value define क
Example - int personAge = 26;
30. क एक क क
Example - int personAge = 26;
क variable क value run time (dynamically) user input क variable
क initialize क declare क क first stage
Taking input from user
Run time variable value input क क ए Scanner class क object create क
class क क क methods provide क keyboard input क क ए क
क data type क ए methods provide क ए Object ए क उ
argument System.in क System.in क क keyboard type क
Value read क क ए object methods क क क
integer value read क क ए nextInt(), string क ए nextLine() औ float value read क क ए
nextFloat() methods call क क
Example
int PersonAge; // variable declaration
Scanner s = new Scanner(System.in); // Scanner class object
PersonAge = s.nextInt(); // reading from keyboard
31. Chapter 6
Strings
This chapter covers:
What are strings?
Operations on strings
Introduction to java strings
Strings characters क sequence क "Java in Hindi" एक string Java strings क
objects क implement क ए क , क strings operations perform
क क Operations क 2 strings क compare क strings perform क
क String एक class normal string variables create क क औ string class क
object create क क औ क operations perform क क
String myString = "this is a string"; // variable
String myString = new String("This is a string"); // object
String क एक variable क औ एक object क क क string क object
क क एक object create क उ क change क क उ क
ए ऊ ए ए example क myString object क क text "This is a
33. String indexing with charAt()
method string क एक method क extract क क ए क Strings क indexing
arrays क character 0 index ए string क क single
character क access क क क ए charAt() method क index number
method pass क method उ index क character क return क
String myString = "hello";
System.out.println(myString.charAt(3));
String indexing with substring()
क string sub string search क क ए substring() method क method
2 arguments pass क argument index number string क access क
औ argument index number क क string access क
method starting index क ending index क क string return क
String s1 = "hello my name is khan";
System.out.println(s1.substring(5,8));
String indexing with indexOf()
क sub string क index क क ए indexOf() method क method
एक sub string pass क method उ sub string क stating index return क
String s1 = "hello my name is khan";
System.out.println(s1.indexOf("my")); //returns 7
35. Chapter 7
Arrays
This chapter covers:
What are arrays?
Creating an array
Initializing an array
Displaying an array
Introduction to java arrays
क क क 200 employees क क information store क employees क
information separately store क क ए क 200 variables क क क क
human variables क create औ manage क क क 200
औ क program क क ए arrays क उ क
एक array similar data type क values क collection Array similar information क
group क employees क salary क array क employees क salary store
क क क type क array create क क क int, float, char type क
variable create क उ क values उ क array create क उ क size
define क array क size उ values उ store क क Array
values क indexing क store क index एक different variable क represent क
36. Arrays क index zero ए क array क size n last element (n -1)
position store
Elements 4 6 9 10 22
Index 0 1 2 3 4
array क size 5 क array क last element 22 4th position store क array
क index zero
Creating java arrays
Java arrays create क क class क object create क क उ
type arrayName = new type[arraySize];
array_name[0]; // first variable
array_name[1];// second variable
..
..
array-name[n-1]; // last variable
37. type type type क array create क
arrayName array क unique ए
new Array क memory allocate क क ए new keyword क
arraySize array क size क integer define क
क array क elements store क
int salary = new int[10];
Initializing arrays
Arrays क 2 initialize क क क variable क java क क index क
initialize क क क उ
salary[0] = 25000;
salary[1] = 10000;
..
..
salary[9] = 30000;
क values input क क
38. Scanner s = new Scanner(System.in);
salary[0] = s.nextInt();
क time consuming क एक loop क औ values क एक
input क
Scanner s = new Scanner(System.in);
for(int i=0;i<10;i++)
{
salary[i] = s.nextInt();
}
Displaying arrays
Arrays क values 2 print क क single index क value print क क
औ array क print क क
System.out.println(salary[0]); // prints value of first index
39. for(int i =0; i<10; i++)
{
System.out.println(salary[i]); // prints all array
}
Multidimensional java arrays
क array क example one dimensional array Arrays क क dimensions
क 2 dimensional arrays क क Two dimensional arrays create क क ए row
औ column size क table create क square brackets rows क औ
brackets columns क represent क
Creating two dimensional array
int TwoDiem [][] = new int [3][4];
Initializing two dimensional arrays
Scanner s = new Scanner(System.in);
System.out.println("Enter the array elements");
for(int i=0; i<3;i++)
{
43. Operator Explanation Example
Logical AND
(&&)
क operators क variables क value
true result true false
a&&b
Logical OR (||) क operator क variables क
एक value true result true
a||b
Logical NOT (!) एक unary operator variable क
क उ variable क value क उ क
!a
Bit-wise operators
Bit-wise operators bit by bit operations perform क क ए क operators
variables क values क bits convert क क उ operations perform क Bit wise operators
4 क क
Operator Explanation Example
Bit wise AND (&) operator क 2 variables क क
उ क common bits क result variable copy क
a&b
Bit wise OR (|) operator क 2 variables क क
उ क uncommon bits क result variable copy क
a|b
Left shift (<<) operator क क variable क value क bits a<<b
44. convert क क उ क bits क left shift क
क bits क क variable क
right
Right shift (>>) variable क क variable क value क bits
convert क क उ क values क right shift क
क bits क shift क variable क
right
a>>b
Relational operators
Relational operators 2 variables क relation क क ए क क
if statement क operators क 2 variables क relation क
क variables एक औ एक
Operator Explanation Example
Equal to (==) variables equal result true a==b
Not equal
to(!=)
variables एक क equal result true
return
a!=b
Greater
than(>)
left side क variable right side क variable
result true
a>b
Less than(<) left side क variable right side क variable
result true
a<b
Greater than
equal to (>=)
left side क variable right side क variable उ क
result true
a>=b
45. Less than
equal to (<=)
left side क variable right side क variable उ क
result true
a<=b
Assignment operators
Assignment process क simple औ fast क ए java क assignment operators provide क
क
Operator Explanation Example
Simple assignment (=) operator right value क value left variable क assign
क
a=b;
Plus assignment (+=) operator left औ right variables क value क add क क
left variable store क
a+=b;
Minus assignment(-=) operator left side क variable क value right side क
variable क value क result left side क variable
store क
a-=b
Multiply
assignment(*=)
operator left औ right side क variables क values क
multiply क क result left side क variable store क
a*=b
Divide assignment(/=) operator left side क variable क value क right side क
variable divide क क result left side क variable store
क
a/=b
46. Conditional operator (?:)
Conditional operator java क special operator if statement क क क
ternary operator क variables conditions क according values store क क ए
क operator ? एक condition , condition true colon
value colon क value variable store
Example
a=5, b=3;
c= a>b?a:b; // c a क value store क ए
47. Chapter 9
Control Statements
This chapter covers:
What are control statements?
Types of control statements
Introduction to control statements
क क उ क क ए क क उ क
क condition क उ औ क क condition
क क action क control क क condition based
क program उ क statements क execution क क condition क control क
क औ condition statements execute क उ execute क
क
क एक उ क Gmail क website id औ password
email औ password check क क email औ password
email password क account औ email password
क एक message show क क control statements क क
Control statements statements program क execution (flow) control क
क statements क execute control statements क क Java क
pass 3 क control statements selection statements एक statement क condition
48. क according select क क execute क Iteration statements क क statements क
execute क क औ jump statements program एक क क
क क क
Types of control statements
क control statements क
Selection statements
Selection statements क statement क condition check क क select क क execute क
condition true क statements क execute क औ condition false
क statements क execute क Selection statements 3 क क
क
IF statement
IF statement क ए if keyword क क keyword क brackets condition
condition variables related क औ क normal condition क
Condition क statements क block Condition true statements execute
औ condition true if block skip क
int a =5, b = 3;
if(a>b)
{
System.out.println("A is bigger than B");
}
49. IF ELSE statement
IF ELSE statements IF statements क क IF ELSE statements condition
false क statements क execute क क
int a = 5, b = 3;
if(a>b)
{
System.out.println("A is bigger than B");
}
else
{
System.out.println("B is bigger than A");
}
Switch statement
Switch statements switch keyword क ए एक condition pass क औ cases ए
ए case condition match क case execute क क variable
क value 3 case क statements execute क क क क क case
condition match क situation default case execute
Switch(2)
{
case 1:
//this will not be executed
Break;
50. case 2:
// this will be executed
Break;
Default:
//this will not be executed because case matched.
}
Iteration statements
क क क एक statement क execute क क Iteration
statements क statements क execute क क क condition true
Condition false execution क क variable क value print
क क क ए क print statements क क एक
iteration statement औ क statement क क execute क
Iteration statements एक statement क execute क क क looping
statements क 3 क क
For Loop
For loop loops simple औ क loop For loop क structure
क
for(initialization;condition;increment)
{
//statements
}
51. For loop क initialization part एक variable क initialize क क value integer
क loop क starting point variable क value loop
क variable क condition include क loop execute क
For loop क condition part loop क condition condition क loop
terminate condition loop infinite क क condition
true क loop Condition false loop terminate
Increment part initialized variable क increment क क loop क execution ढ़
क औ condition उ execute क terminate variable क increment
क क ढ़
class IterSta
{
public static void main(String args[])
{
for(int i=1; i< = 10; i++)
{
System.out.println("Numbers form 1 to 10 ");
System.out.println(i);
}
}
52. While loop
While loop for loop While loop initialization statement loop क
Brackets क condition औ increment part block क Increment part क
statements क
class WhileStat
{
public static void main(String args[])
{
int i = 1;
while(i<=10)
{
System.out.println(i);
i++;
}
}
While loop क feature क क variable initialize क क
loop क terminate क क ए क condition क क क
program क variables related क condition क
While loop क statements क initialize क क क क for loop क
क क
53. Do - While loop
For औ while loop statements execute condition true क
statements क execute condition check क do-while loop एक
statements execute उ क condition check क एक
Condition true false एक क loop statements execute क check क
condition true loop continue क terminate
class doWhileStat
{
public static void main(String args[])
{
int i = 0;
do
{
System.out.println(i);
i++;
}while(i<=10)
}
}
Jump statements
Jump statements program एक क क क
Break statements
55. Chapter 10
Classes
This chapter covers:
What are classes?
Advantages of classes
Creating a class
Introduction to java classes
Java क class class? औ java क class क
क क क class एक type क data types class type क
variables create क क क class type variables objects क Class क
variables औ functions क group structure create क औ उ एक
identify क structure क base क object create क क
Class एक entity औ उ related attributes क class क क क
information store क represent क क ए क क variables क क क
, उ , औ क क क क 100 क information store
क situation क 100*4=400 variables create क एक
क ए classes क introduce क Class क 4 variables क एक type create
क क औ उ type क 100 objects create क क Object क class क
variable क access क क value assign क क क उ
56. class Person
{
String name;
int age;
int phone;
String address;
}
एक java program क classes create क क क main method एक class
Main method program क execution start
Advantages of classes
ढ़ क classes क advantages
Security
क variables औ methods classes Classes 3 level क access protection provide क
क क क क class members क access क क
Reduce complexity
Classes क क variables औ methods क Classes क program
simple औ उ क complexity
Separation
क program क क क क data data operations
perform क methods क perform क Classes क क ए एक type क
57. data औ उ related operations (methods) क type क data औ उ related operations
(methods) separate क क
क data क ए class क क क उ data perform
operations (methods) उ class create क क क program क manage क
क एक class purchases क information store क क ए औ
class sales क information store क क ए क
Focus on data
classes क program क focus data data क ए methods
create क औ data क hide क Classes data focused approach क useful software
क ए
Creating a class
Class create क क ए class keyword क क Class keyword क
class क क program एक क classes class क unique
ए class main method class public declare क ए Class create क
क उ
class Person
{
String Name = "Vipin";
int age = 24;
public void display()
{
58. System.out.println("Name is "+Name+"Age is"+age);
}
public static void main(String args[])
{
this.display();
}
}
ऊ ए ए उ person क एक class create क class name औ age 2
variables display() method declare क Main method display()
method क call क
Main method
क program एक क classes क क main method एक class
program main method program क execution start class main
method उ public declare क necessary
Main method क public declare क ए क ए क classes
methods by default private औ main method क public declare क java
run time environment क main method क access क औ क program क
execution start
क class क क method क access क क ए objects क Java run
time environment क main method क object क access क क ए main method क
static declare क
59. क necessary terms क क क
Instance variables/methods
variables औ methods class क object access क उ instance variables
methods क
Static variables/methods
Static variables औ methods क objects क access क क क variable
method क static क ए static keyword क Static members क access क क
ए class क क (.) operator क उ member क
Command line argument
Main method क parameters क string array command line argument क ए
क Command line arguments arguments program क run क
क क क program run क argument क क
program उ arguments क according run क
60. Chapter 11
Objects
This chapter covers:
What are objects?
Creating objects
Introduction to java objects
integer एक type class एक type Class type create क क ए क object
create क Class क variables औ methods उ class क access क क
ए क उ class क object create क Object create क क उ class क
variables क access क क औ methods क call क क Objects create क क ए new
keyword क उ क Objects create क क क steps ए
1. class क object create क उ class क
2. Class क क object क object क unique ए
3. क equals (=) operator
4. क new operator
5. New operator क class क औ उ क brackets क semicolon
61. Example
class Person
{
String Name="Vipin";
int age=24;
public void display()
{
System.out.println("Name is "+Name+ "Age is"+age);
}
}
class PersonObj
{
public static void main(String args[])
{
Person p1 = new Person();
p1.display();
}
}
62. ऊ ए ए example 2 classes क program क execution उ class start
PersonObj class start class person class क object create क Person class
क object create क क उ class क object क (.) dot operator क display method क call
क object उ class क क member (variable method) public
access क क
क object create क उ class क constructor call Class क क
brackets ए class क constructor क call क
objects क variables क 2 parts create क क part object
क declare क औ part initialize क
Example
Person p;
p1 = new Person();
objects क create क क initialize क reference variables क
Example
Person p1;
This keyword
This keyword current object क represent क Current object क currently
class क क औ उ class उ class क object क क This keyword क
63. क this keyword उ situation क current object क
क member क point क This keyword क constructors क
class PersonName
{
string name;
public PersonName(string name)
{
this.name = name;
}
public void show()
{
System.out.println("Name is : "+name);
}
}
class ThisDemo
{
PersonName pn = new PersonName("Vipin");
pn.show();
}
क ऊ ए ए उ क this keyword PersonName class क name variable क
औ constructor ए ए parameter क distinguish क क ए क this
keyword क compiler क क क name क क name assign क
क situation current object क member क point क उ क ए this
keyword क क This keyword क एक argument क क क
65. Constructor एक method क
Constructor क class क
Constructor क क return type
Types of java constructors
Java 4 क constructors क
Default constructor
क constructor create क java automatically default constructor call क
constructor variables क उ क values क according memory allocate क
Normal constructor
constructor create क औ क body class variables क compile time
initialize क क उ
class Person
{
String Name; int age;
Person() //Constructor
{
Name = "Vipin"
age = 24;
}
66. public void display()
{
System.out.println("Name is : "+Name+" Age is : "+age);
}
}
class NorCon
{
public static void main (String args[])
{
Person p1 = new Person();
p1.display();
}
}
Parameterized Constructors
Constructors parameters pass क क Objects ए क variables क
value arguments क pass क क values constructor variables क assign क क
क उ
class Person
{
String Name; int age;
Person(String n , int a )
67. {
Name = n ;
age = a ;
}
public void display()
{
System.out.println("Name is : "+Name+" Age is : "+age);
}
}
class ParaCon
{
public static void main (String args[])
{
Person p1 = new Person("Vipin",24 );
p1.display(); }
}
Copy constructor
Copy constructor क क object क copy क क ए क एक object क value
object copy क objects same values क point क Copy constructors
class क object create क उ class क object argument क pass क
class Person
{
68. int age;
Person(String n , int a )
{
Name = n ;
age = a ;
}
Person(Person p ) // Copy Constructor for p2 object
{
Name = p.Name;
age = p.age;
}
public void display()
{
System.out.println("Name is : "+Name+" Age is : "+age);
}
}
class CopyCon
public static void main (String args[])
{
Person p1 = new Person("Vipin",age);
Person p2 = new Person(p1);
p1.display();
p2.display();
}
}
69. Chapter 13
Methods
This chapter covers:
What are methods?
Structure of method definition
Structure of method call
Introduction to java methods
क क क एक क क एक task क program क perform क
क क methods क क क एक code क क
एक method operation क perform क क क एक
code क task perform क , उ उ
method क call क क
Method basically एक block of statements block एक particular operation perform क
operation क program perform क method क क उ call
क औ compiler उ method क execute क
Java methods क उ println() method क क क program
क method क क क ?? method java
library define क method क क क क क string क क उ क
screen print क क method variables क pass क क उ क values print
70. क क क method क क call क औ string
variables क औ method उ execute
java library method क definition ए क उ code program
क औ उ code क क क hello world program 10 line
क
Methods program code क reduce क औ computer क memory क
methods क programmers क same code programmers
क time
Structure of method definition
access_specifier return_type method_name (parameters list)
{
// statements to be executed
}
access specifier Access specifier show क क method क क क private,
public protected
return type Method क execution क method result क क क value
return क define क क method क value return
क void
method name method क program unique ए
parameters list variables values method क call क pass क
71. Method operation perform क औ result return क
execution क ए क उ क क addition क method
उ 2 numbers pass क क क क add क क method क
result return क values औ variables क comma separate क
Structure of method call
If in the same class If in another class
methodName(arg1,arg2….); objectName.methodName(arg1,arg2);
Example
class PersonsInfo
{
public void Separator()// our method which separates information of persons
{
System.out.println("---------------------------------------------------------------------------
--");
}
public static void main(String args[])
73. methods क same क methods parameter types औ उ क
compiler run time क क method execute क
method arguments match method execute
Example
public class overDemo
{
public static int sum(int a, int b)
{
return a+b;
}
public static int sum(double x, double y)
{
return x+y;
}
public static void main(String args [])
{
System.out.println(sum(3,5));
System.out.println(sum(3.5,5.3));
}
}
74. ऊ ए ए example 2 sum methods एक sum() method integers क add क औ
double values क add क Method call क sum() method integers pass क
integers sum() method execute औ double values pass क double
sum() method execute
Method overriding
क class क inherit क उ क methods क access क क क
क method क definition क sub class क according उ method क
change क super class क क method क sub class define
क क उ method क edit क क क sub class क ए work क क method
overriding क
Method overriding sub class super class method क औ उ
method क edit क क क क क super class क method क override क
उ क ए एक class Area औ उ display() method class क Circle class inherit
क Circle class Area class क display method क क क उ method क Circle class
क क क edit क क क Area class क एक rectangle class inherit
क display() method क क क क क define क क
क method क override क क 2 ए
Super class क method क औ sub class क method क same
Sub class क parameter list super class क parameter list match ए
75. Example
class Area
{
public void display()
{
System.out.println(“Displaying area……..”);
}
}
class circle extends Area
{
public void display()
{
System.out.println(“Displaying circle…….”);
}
public static void main(String args[])
{
Area obj = new Area();
obj.display();
this.display();
}
}
76. Chapter 14
Inheritance
This chapter covers:
What is inheritance
Types of inheritance
Inheriting a class
Example
Introduction to java inheritance
क क क औ उ क उ क एक
class क (super class) क , औ class क (sub class) क क एक
class class क properties (methods, variables ) क access क क क
(sub class) क (super class) क property(methods, variables ) क access क क
क
क क क class औ class क methods क क
class क क methods क क class उ
methods क access क क क क ए class methods क access क उ
class क sub class Sub class क ए क class क उ class क extend क
inheritance क
Inheritance एक code क क उ Inheritance क क re-
usability क एक code क reuse क क
77. क एक class class क inherit क extends keyword क औ
क क क class क क class inherit क क ए class क
final keyword classes क final keyword उ inherit क
क
क class एक class क extend क क क class एक क classes क extend
क multiple inheritance क औ क क multiple
inheritance allow क multilevel inheritance implement क क
class क inherit क super class क औ class inherit क sub class
क एक क sub class super class क methods औ variables
क access क क methods public औ protected declare क ए उ sub class
access क क Super class क क private member क sub class access क क
super class क औ class क extend क उ class क public औ protected
members क क class क क
Types of java inheritance
Java 3 inheritance क क क application क ए क suitable
क क क क क
Single Inheritance
Single inheritance एक class क क extend क क क inheritance क
उ basic programming क
78. Multilevel inheritance
Multilevel inheritance एक class class क extend क औ class class क
extend क
Hierarchical inheritance
Hierarchical inheritance एक class क classes extend क inheritance क
क super class क task क क sub task
Inheriting a class
क class क inherit क extends क उ क class क क
extends keyword औ उ क class क inherit क उ class क
Inheritance क उ
79. class A
{
public void display()
{
System.out.println("This is A class");
}
public static void main(String args[])
{
display();
}
}
class B extends A
{
public static void main(String args[])
{
display();
}
}
80. Chapter 15
Exception Handling
This chapter covers:
What are excetions
Keywords (try, throw, catch)
Steps to handle exceptions
Some common exceptions
Example
Introduction to java exception handling
Exceptions run time errors Exception एक situation क ए program
क क क memory क program क execute क ए ए, उ memory
क computer क program क execution क out of memory
exception situations क exceptions क
क program क statement क semicolon , क
program error क औ compile उ क exception generate क
program क execute
क क program exception क execute क ए क
exceptions क handle क exception handling क exceptions क handle
क क program exception क क exception code क skip क क क
क code क execute क
82. औ catch block क finally block क execute क
Steps to handle exceptions
1. उ code क try block exception generate क
2. Try block क catch block exception क handle क क ए code ए क
exception related क message print क क
3. Exception handle क क code execute क उ finally block
Some common exceptions
Exceptions क handle क exceptions क क ए क exceptions
java regularly common exceptions practice क क
औ skill क improve क क Java regularly क common exceptions क
Arithmetic Exceptions
क arithmetic error क क number क zero divide क क क क क
variable उ क size value store क क क क Arithmetic-Exception generate
Class Cast Exception
क class क reference class store क औ class class क
sub class Class-Cast-Exception generate
83. Array Store Exception
string array औ उ string store क क क क Array-Store-
Exception generate
Array Index Out Of Bounds Exception
क array क size 10 औ 11th position value store क क क क 11th
position क access क क क क Array-Index-Out-Of-Bounds-Exception generate
Illegal Argument Exception
क method invalid argument pass क क int क string क Illegal-
Argument-Exception generate
Null Pointer Exception
Java क reference variable क null value assign क क क reference
variable क क क क NullPointerException generate
Number Format Exception
क string value क number cast क क क क Number-Format-Exception
Example
Import java.lang.*;
class
{
public static void main(String args[])
84. {
int num = 120;
int a = 0;
try
{
num = num / a;
System.out.println(num);
}
catch(ArithmeticException e)
{
System.out.println(“You can not divide a number by zero”);
}
}
}
85. Chapter 16
Interfaces & Packages
This chapter covers:
What are interfaces?
Example
What are packages?
Creating packages
Using packages
Some common packages
Introduction to java interfaces
Java interfaces क concept एक उ क क क एक औ
क क एक क एक क क क क
ए क क क क sales department, production department,
accounts औ management department क setup क क
क क क क क क depend क interfaces
classes क क उ क Class क क क उ class depend क
Java interface उ क exam time topics क headings क क औ ए
उ headings क detail क Interface क boss क औ class
क employee क interface क क औ class उ क क क Interface क
क क Interface define क ए methods क क क task क ए
interface क
86. Interfaces define क ए methods by default abstract क क body
Interface क public declare क क class interface क implement क
उ implement declare क ए methods क definition provide क क
method क क एक interface क क class extend क Interfaces
implement क क ए implements keyword क
Java multiple inheritance allow क java interfaces क multiple inheritance
implement क क Interfaces super class क methods provide क , उ क
definitions implement क class Interfaces classes क , क
क object create क क औ क method क body declare क क
Methods क interfaces variables declare क क Interfaces declare क
variables static औ final ए एक interface एक interfaces क extend क
क एक interface declare क क क classes उ interface क implement क क
औ एक class उ interface implement क क क ए क interfaces क
क (,) separate क
Interfaces classes क Is-a relationship establish क उ क ए क pass एक
interface fruits color औ taste methods औ एक mango क class
mango class fruit interface क implement क Is-a relation क क
क Mango is a fruit.
Working with interfaces
Interfaces क declare क क क ए interface keyword क
public access modifier define क , क interface keyword क interface क
क curly brackets उ methods क declare क क class
implement क interfaces क methods by default public क
87. public access modifier methods क add क क क उ
Structure Example
public interface interface_Name
{
// methods without body;
}
public interface yrFriend
{
public void sales();
public void production();
public void accounts();
public void management();
}
क क implements keyword क क ए क class interface क
implement क क Interfaces क complete उ
Example
public interface yourFriend
{
public void sales();
public void production();
public void accounts();
public void management();
}
88. public class You implements yourFriend
{
public void sales()
{
// implement sales department
}
public void production()
{
// implement production department
}
public void accounts()
{
// implement production department
}
public void management()
{
// implement production department
}
}
89. Introduction to java packages
java library ए क उ classes क उ क category क according
packages organize क उ classes क क क packages क
import क क ??. Classes क directly access क क
Packages related types (classes, Interfaces etc.) क group क एक package
क package क क
क क क eCommerce software क क क source code क lines
lines क एक programmer lines क software क
??. क क उ क ए क एक software क
programmer क
क क क programmers क code एक execute क possibility
क क 2 programmers class interface क same
situation program error show क problem क ए java एक mechanism provide
क package क
programmer code एक package क क programmers
classes interfaces क same क program error
Packages क क क ए क क क क क एक class
method औ variable create क औ क class क program
क error उ क packages क same classes क
error generate क
90. Features of packages
Packages क java classes औ interfaces क maintain क क
Packages क category क classes क packages maintain
क क क programmer क productivity ढ़
Java packages क classes औ interfaces क access protection provide क
package class create क क access modifier क उ class क
packages क classes access क क क उ class package private
modifier apply
Java packages duplicate names क problem solve
Creating java packages
Package create क क ए package keyword क keyword क package क
unique
package myPackage;
क file क line ए क classes औ interfaces create क
उ package include ए क classes क एक package add क
files क एक file क क क क files
top statement classes उ package include ए
91. Using java packages
क programmer क package क क class क क उ क package
import क
import myPackage;
Package क import क क classes क क क क क
programmer क package क import क क औ उ क classes क क क
क (.) operator क क class क directly access क क package
member access क situation उ class क access क
import newPackage.myClass
Some common java packages
Java एक main package Java API package क package क
क क ए packages program import क क क क IO
package औ AWT package
क common औ क packages क क क
क
92. java.language
package language support classes classes java compiler क
ए classes important
java.util
package language utility classes provide क क vector, hashtable
java.io
pacakge input ouput support classes provide क data क input औ output क ए facility
provide क
java.AWT
package graphical user interface implement क क ए classes
java.net
package networking क ए classes provide क server connection establish क क
ए classes
java.applet
package applets create क औ implement क क ए classes provide क
Sub packages
क package क एक औ package create क package sub package
क क classes क categories क क क sub packages क
packages क categories क क
93. Chapter 17
Multithreading
This chapter covers:
What is multithreading?
Thread class
Runnable interface
Synchronization
Introduction to java multi-threading
phone क ए क औ TV क क
क एक क क क क multitasking क java क क
एक क क complete क क Java क feature क multi-threading क
उ क ए क user input क ए wait क क क
complete क क database connectivity क क क file क upload क
क
एक multi-threading क 2 2 क parts parts एक execute क क
part thread क thread एक unique task complete क क ए responsible
threads main thread क program क main main() method क
thread क एक life cycle life cycle thread क stages thread
क object ए क , एक thread new state क thread
object start() क क thread runnable state क run()
94. method क thread running state क thread क execution क ए wait
क thread waiting state औ thread क execution complete
thread destroyed stage
Java multi-threading 2 implement क क क thread क extend
क क Runnable interface क implement क क run()
क methods program क thread क extend क क औ
run() override क Runnable interface implement क क
Thread class implementation
Thread class methods provide क क thread class क implement क क ए
क methods क override क क क run() override क क
Thread class क क important methods ए
Method Description
getName() Returns name of thread.
getPriority() Returns priority of thread.
isAlive() Returns true if thread is active.
join() Joins two threads.
run() Threads task is defined in this method.
sleep() Make a sleep for give time in milliseconds.
start() Starts a thread.
क thread class क extend क क run method क
override क औ methods क override क क क run() method क
override क necessary क class क object create क Object create
क thread क एक unique क क
95. Object create क क उ object start() method क क start() automatically
run() method क call क , औ क thread क execution start threads
create क उ object create क
class JavaHindi extends thread
{
public static void main(String args[])
{
JavaHindi jh = new JavaHindi();
jh.start();
}
Public void run()
{
System.out.println(“Thread is running at www.besthinditutorials.com”);
}
}
Runnable interface implementation
Runnable interface एक method run() method क definition क class
provide क एक class create क , run() क implement क
क Thread class क object ए क thread क object Runnable
96. interface क implement क class क object औ thread क क औ उ क
thread class क object start() method क call क
Runnable interface क implement क क object thread क object pass
क thread क object उ class क object क point क क उ
class JavaHindi implements Runnable
{
JavaHindi()
{
Thread t = new Thread(this,HindiThread);
t.start();
}
Public void run()
{
System.out.println(“Thread is running at www.besthinditutorials.com”);
}
public static void main(String args[])
{
JavaHindi jh = new JavaHindi();
}
}
97. Synchronization
2 2 क thread क एक resource (method) access , conflict
conflict क ए एक technique क technique एक एक thread
resource access क क technique क synchronization क
Synchronization क technique क method क synchronized क ए उ
क definition synchronized method add क क synchronized void
myMethod(){}.
Synchronization क concept क क ए क monitor क concept object क
उ क monitor क thread synchronized क call क , monitor
enter thread monitor enter उ resource lock क
thread resource क free क क क thread resource क access क
क
क resource क synchronized क 2 क एक क क method क
synchronized keyword क औ उ synchronized क क एक
synchronized block create क औ block उ class क methods क क क , क
synchronized क उ
Synchronized(s1) // s1 is the object of class of which methods you are going to call
{
// call here methods that you want to make synchronized
}
98. Chapter 18
File I/O
This chapter covers:
What are streams?
Byte streams
Character streams
Introduction to java file I/O
program input क program run क क console क
क औ output console क software data क
एक execute क क input क human क क क Input
क क output क क क क human क computer क screen
possible क क output क क क औ execution
क print क situation java क File I/O क mechanism क क क
Java क classes provide क क input क file read क क औ
output क file store क क input console क
क file read क क औ output console क ए क file store क क क
Files क input औ output operations perform क क ए stream क क Data क
sequence क stream क Input stream input औ output stream output
99. Java streams 2 क Byte stream data bytes क form औ character
stream data character क form क streams क
Byte stream
Byte stream data bytes क form input औ output क ए 2 classes provide क
abstract classes classes methods provide क क files
क operations perform क classes क
InputStream
एक abstract class byte input stream class FileInputStream class extend क
औ क methods क file operations क ए क
Method Description
int read() Reads data from file in form of bytes.
void close() Closes input stream
FileInputStream एक byte stream input class class क object create क क byte input
stream create क object different methods call क क files क operations
perform क
import java.io.*;
public class FileIOExample
{
public static void main(String args[]) throws IOException
100. {
FileInputStream in = new FileInputStream("directory-address-of-file");
int a;
while((a = in.read()) != -1)
{
System.out.println((char)a);
in.close();
}
}
}
OutputStream
एक abstract class एक byte output stream class FileOutputStream class extend
क class क क methods ए ए FileOutputStream class क
Method Description
int write() Writes data to file in form of bytes.
void close() Closes output stream
FileOutputStream class एक byte stream output class class क object ए
क औ उ object write method call क क bytes() क file write() क
import java.io.*;
101. public class FileIOExample
{
public static void main(String args[]) throws IOException
{
FileOutputStream out = new FileOutputStream("directory-address-to-store-file");
a = 5;
out.write(a);
out.close();
}
}
Character Stream
Character stream data bytes क characters क form Character stream
input औ ouput क ए 2 abstract classes क classes क
Reader
Reader एक abstract class एक character input stream class FileReader class extend
क class क methods ए
Method Description
102. int read() Reads data from file in form of characters.
void close() Closes output stream
FileReader एक character input stream class Reader class क extend क class क
object create क क character input stream create क उ object read method call
क क data read क
import java.io.*;
public class FileIOExample
{
FileReader in = new FileReader("director-address-of-file");
int a;
while((a=in.read())!=-1)
{
System.out.print((char)a);
in.close();
}
}
103. Writer
एक abstract class एक character output stream class FileWriter class extend क
class क क methods FileWriter class क
Method Description
int read() Writes data to file in character form.
void close() Closes output stream
FileWriter class क object create क क character output stream ए क उ object
write() method call क क data write() क
import java.io.*;
public class FileIOExample
{
public static void main(String args[]) throws IOException
{
FileWriter out = new FileWriter("directory-addres-of-File");
int a = 5;
out.write();
out.close();
}
}
104. Chapter 19
Serialization
This chapter covers:
What is serialization?
Serializable interface
Introduction to java serialization
क video game औ उ क क क क ए
औ video game क क औ video
game start क game क game start क क क
क game क क क program क
processing क उ क क Java क feature क
Serialization क
Serialization object क state क save क क क music player क
उ pause औ play क feature add क song क pause क क play
क औ song क क music player क ए
situation serialization क क क
क object क state क save क process serialization क औ उ
object क restore क process de-serialization क Object क state byte stream
क क file store क
105. क object क serialize क क object क serialize क
उ क data members क value file store क क variable EmployeeName
औ क employee क store क variable उ क file store
object क De-serialize क value memory load
Serializable interface
क object क serialize क क ए क serializable interface implement क
class serializable interface क उ क objects serialize क क
class ClassToSerialize implements Serializable
{
String Name = "YourName";
int Age = 24;
}
Serializing objects
क object क serialize क एक file ए औ object क current state उ file
store क object क serialize क क ए ObjectOutputStream class क object
create क class क object create उ FileOutputStream class क object
argument क pass क क ObjectOutputStream class क object writeObject()
106. method call क object serialize क उ method argument क
pass क
ऊ ए उ क क एक class serializable interface क implement क
क क class क objects क क serialize क क उ
import java.io.*;
public class HowToSerialize
{
public static void main(String args[]) throws IOException
{
FileOutputStream fstream = new FileOutputStream("directory-address-of-file);
ObjectOuputStream obstream = new ObjectOutputStream(fstream);
ClassToSerialize CTS = new ClassToSerialize();
obstream.writeObject(CTS);
}
}
107. De-serializing objects
क object क processing क उ क state file memory
load क क object क file memory load क क ए ObjectInputStream
class क object create क Object create क FileInputStream class क object
argument क pass क क ObjectInputStream class क object readObject()
method call क method क उ class क object return क ए क उ class
क reference variable cast क क store क
import java.io.*;
public class HowToSerialize
{
public static void main(String args[]) throws IOException, ClassNotFoundException
{
FileInputStream fstream = new FileInputStream("directory-address-of-file");
ObjectInputStream obstream = new ObjectInputStream(fstream);
ClassToSerialize CTS2 = (ClassToSerialize) obstream.readObject();
System.out.println(CTS2.Name);
System.out.println(CTS2.Age);
}
}
108. Chapter 20
Collections Framework
This chapter covers:
What are collections?
Other interfaces
Introduction to collections framework
data structures ढ़ java collections क Java
objects क एक organize क क ए क data structures (set, list, queue and array)
क data structures क java collections क data structure क collection क
collection framework क collections क objects क operations (
searching, sorting, insertion, deletion ) perform क क normal data क क
Collections framework क क क क ए classes औ interfaces provide
क ए classes interfaces क implement क classes क extend क क
objects क organize क क क data structure ए क क Collections
framework क interfaces औ classes generic , ए object क type collection ए क
interfaces औ classes क
110. ArrayList
ArrayList<objType> ArrList = new ArrayList<objType>();
arrList.add(obj1);
arrList.add(obj2);
arrList.add(obj3);
LinkedList
LinkedList<objType> linklist = new LinkedList<objType>();
linklist.add(obj1);
linklist.add(obj2);
linklist.add(obj3);
Set interface
HashSet or TreeSet classes set interface क implement क Set collection objects क
set क store क duplicate objects store क क क
class क object create क क set collection ए क क
111. HashSet
HashSet<objType> hSet = new HashSet<objType>();
hSet.add(obj1);
hSet.add(obj2);
TreeSet
TreeSet<objType> tSet = new TreeSet<objType>();
tSet.add();
tSet.add();
Queue interface
Queue interface क PriorityQueue class implement क collection
objects store क First In First Out क form store
PriorityQueue
PriorityQueue<objType> pQueue = new PriorityQueue<objType>();
pQueue.add(obj1);
112. pQueue.add(obj2);
Map interface
HashMap औ TreeMap class Map interface क implement क Map collection data key औ
value क pair store क element क store औ access क क ए key क
Map collection elements unique
HashMap
HashMap<objType> hMap = new HashMap<objType>();
hMap.add(key,obj1);
hMap.add(key.obj2);
TreeMap
TreeMap<objType> tMap = new TreeMap<objType>();
tMap.add(key,obj1);
tMap.add(key,obj2);
114. Chapter 21
Lambda Expressions
This chapter covers:
What is functional interface?
What is lambda expression?
Functional interface
Lambda expressions क क functional interface क एक
functional interface interface , क एक abstract method क multi-
threading क ए क runnable interface एक functional interface क
interface क क उ define क एक method define क
उ क ए एक interface ए क एक function interface interface क
welcome interface एक hello() क by default abstract method एक
argument औ message print क
interface Welcome
{
String hello(String name);
}
115. Lambda expressions
Lambda expression एक क method method क क type क
body एक single statement क क curly braces औ return statement क
method execute Lambda expression functional interface क
abstract method क signature क
Lambda expressions क क क क , type क available
क variable initialization, return statement औ method argument औ
conditions type क available lambda expression क क
Lambda expression create क क ए lambda operator (->) क एक simple
operator , क left side parameters औ right side method body
lambda body क
Lambda expression क result उ interface क reference variable store क क
signature क उ class क reference variable ए क क
functional interface क implement क Lambda expression क उ
Welcome wel;
String name = "Vipin";
wel = (name)-> {
System.out.println("Hello"+name);
};
116. Chapter 22
Generics
This chapter covers:
What are generics?
Example
Introduction to java generics
क क addition क method क क क data type क variables क
add क क data type integers add क औ उ method
double add क क possible ??. क possible method
क औ क क
Generics क method क क data type क execute क क
methods data type क parameters क pass क compiler क क
क क data type क method क execute क
Java क feature readability ढ़ , programmers क time औ computer क memory
क क क data type क ए code क
Generics क क reference types (class) क क क क primitive types
क int औ char क generics क क क ए java primitive types
क class क implement क क int क ए Integer औ double क Double
117. क methods classes, interfaces औ constructors क generic क
Generic class क structure
class GenWorld<T>
{
}
क object ए क उ क structure क -
GenWorld<Integer> obj1 = new GenWorld<Integer>(20);
Example
class GenWorld<T>
{
T getValue;
public GenWorld(T n)
{
this.getValue=n;
}
118. public void display()
{
System.out.println(this.getValue);
}
}
public class GenDemo
{
public static void main(String args[])
{
GenWorld<Integer> = intgen = new GenWorld<Integer>(10);
GenWorld<String> Stringgen = new GenWorld<String>(“vipin”);
intgen.display();
Stringgen.display();
}
}
ऊ ए उ क क class क declare क
class क क (< >) brackets generic declare क क
generic
variable declaration क variable क type generic क ऊ
ए क
119. क एक constructor क generic argument
object create क क उ convert
औ
क क generic class क different क
ए क क argument क क object ए क
. क ऊ ए ए उ क
Generic methods
क ऊ ए ए example क एक generic class क method generic type क क
क ए method generic क क class generic
method declare क क generic Generic methods ए क क ए structure
<T> void myMethod(T x)
{
T a = x;
System.out.println("hello",a);
}
120. Generic constructor
Classes औ methods क constructors क generic declare क क क
methods क generic declare क Constructor क generic क ए class क
generic क क उ -
class GenWorld
{
public <T>GenWorld(T arg)
{
// this is is a generic constructor
}
}
Generic interfaces
Classes, methods औ constructors क interfaces क generic declare क क
क क क simple
public interface myInterface<T>
{
public T myFunction();
}
121. public class myClass implements myInterface<T>
{
public T myFunction()
{
//
}
}
Bounded types
ऊ ए ए उ T क क data type replace क क क क क क
क क numbers क क numbers क क
data type pass क क
situation क handle क क ए java bounded types provide क Type parameter(T)
declare क type क उ क super class क extend क क
T क उ super class क types क replace क क क structure
class GenWorld<T extends Number>
{
// class T क numbers क क
}
122. Wildcard arguments
एक क generic क एक particular type argument क object ए क
क object generic क एक particular type क ऊ ए ए उ क
intgen एक generic type क integer argument क ए क ए intgen
औ stringgen क object क उ क क object क refer क
क क object integer type argument क create क क क
क generic क object क print क उ क ए एक function
object क argument क औ print क क ए क
void dispObj(GenWorld<T> obj) // can not do this, because all object are not allowed with
this statement and function checks for strings only.
{
//
}
क ऊ क क क क क क object pass
क क wildcard arguments क क औ function क क
क object क print क क Wildcard क structure औ उ ए
void dispObj(GenWorld<?> obj)
{
}
123. Chapter 23
Event Hanlding
This chapter covers:
Introduction to Event Handling
Different types of event classes
Examples
Introduction to java event handling
क GUI application क क mouse click क क menu क item
select क क button press क events generate क क क
user क action events generate User क action components क state
change , compiler क क event generate events क
क ए handle क क compiler क क mouse click क क औ button
press क क event handling क
class event generate उ source class क औ class event क handle
क listener Event generate , क ए listener class क listener interface
implement क
Event handling उ क क क क क bell bell
एक event generate क event क handle क औ क situation
क source class , औ listener class औ (listener class )
bell Bell listener interface , implement क एक
124. क bell क क क क
क listener interface implement क क क क क event
generate
events क ए क listener interfaces , क mouse related
events क ए MouseListener औ keyboard related events क ए KeyListener Listener
class क events क notification उ interface क implement क उ क
ए Mouse events क Listener interface implement क क source
class क define क क mouse related क event generate क class क
क एक method क , क उ
addMouseListener(MouseListener obj) // obj is object of listener class
statement source class , source generate mouse related
events क notification listener class क औ listener class उ events क handle क
listener interface उ क events possible क उ क ए एक method
methods क override क क event क handle क क क MouseListener interface
5 क mouse events क handle क क 5 method ए methods क
क
public void mouseClicked()
public void mouseEntered()
public void mouseExited()
public void mousePressed()
public void mouseReleased()
125. एक उ क क क क , applets event based program
उ applets क क AWT Swing library क events क
क क
Example
// Source class
public class ListenToMe extends Applet
{
public void init()
{
String msg;
YesSpeak ys = new YesSpeak();
addMouseListener(MouseListener ys);//passing listener object
}
public void paint(Graphics g)
{
g.drawString( msg,30,30);
}
}
126. //Listener class
class YesSpeak implements MouseListener
{
ListenToMe lm = new ListenToMe();
public void mouseClicked(MouseEvent me)
{
lm.msg = "Mouse was Clicked!!";
repaint();
}
public void mouseEntered(MouseEvent me)
{
lm.msg = "Mouse was entered!!";
repaint();
}
public void mouseExited(MouseEvent me)
{
lm.msg = "Mouse was exited!!";
repaint();
}
127. public void mousePressed(MouseEvent me)
{
lm.msg = "Mouse was pressed!!";
repaint();
}
public void mouseReleased(MouseEvent me)
{
lm.msg = "Mouse was released!!";
repaint();
}
}
//HTML file
<html>
<head>
<title>Event Handling</title>
</head>
<applet code="ListenToMe.java" width=300 height=300>
</applet>
</html>
128. Adapter classes
क listener class क listener interface implement क , क उ interface क
methods क implement क क उ क mouse listener class
क interfaces क implement क क क क method क
implement क क क एक method क implement क situation adapter
classes क क क
listener interface क ए एक adapter class provide क , क MouseListener interface क
ए MouseAdapter औ KeyListener interface क ए KeyAdapter adapter class उ
interface क methods क default implementation provide क क methods क
implement क क method क उ override क
Adapter classes क programmers क time क उ
//source class
public class AdapterCall extends Applet
{
String msg;
public void init()
{
AdapterReply ar = new AdapterReply();
addMouseListener (ar);
}
public void paint(Graphics G)
{
g.drawString(msg,30,30);
}
129. }
//listener class
class AdapterReply extends MouseAdapter
{
AdapterCall ac = new AdapterCall();
public void mouseClicked(MouseEvent me)
{
ac.msg = "mouse was clicked";
repaint();
}
}
//HTML file
<html>
<head>
<title>adapter handling</title>
</head>
<applet code = "ÄdapterCall.java" width=300 height=300>
</applet>
</html>
130. Chapter 24
Applets
This chapter covers:
What are applets?
Applets life cycle methods
Example
Introduction to java applets
Applet एक java program browser run एक HTML क
क क क HTML code include क Java program क file औ HTML
program क files HTML java program क load क क ए <applet> tag
क क HTML क browser HTML क java program
load क क ए क applet (java program) क औ HTML file क एक server
save क
Applet java program Applet class क extend क Applet program क .class
extension save क क browser applet क applet क code उ user
क machine download applet क code user क machine download
applet browser ए क क क applets client side applications
Applets क run क ए JVM क JVM browser plugin क क क
system क
131. Applet क browser क एक applet viewer क क applet
program क HTML include क क directly क , java automatically applet क applet
viewer क
एक applet java program main() Applet class क life cycle methods provide
क applet क handle क method क एक specific task perform क क ए
Applet क life cycle methods एक एक execute क
methods क क क
Life cycle of java applets
Applet 5 important methods provide क , override क methods क life
cycle methods क एक applet program life cycle methods क
methods क applet program control provide क methods ए
init() - method variables क initialize क क क object ए क क
क क initialization method क क क applet क background
color set क क
start() - init() method क automatically call method browser applet
क call क
stop() - applet क stop क क ए क applet HTML page क
क क window method call औ applet pause
उ window , applet
132. destroy() - browser क close क call औ applet destroy
paint() - method क applet क draw क क ए क method
start() क call
applet क एक complete उ
Example
// Java code
class picture extends Applet
{
public void init()
{
void setBackground(color.red);
}
public void paint(Graphics g)
{
g.drawString("Applet are for GUI",30,30);
}
}
//HTML code
133. <html>
<head>
<title>applet example</applet>
</head>
<applet code="picture.class" width="300" height="300">
</applet>
</html>
Parameter passing in java applets
java file क HTML file क through parameters क क क क input
user क form क औ further processing क ए क input क java file क pass
क क क ए applet API parameter passing क feature provide क Java
file क parameters pass क क ए HTML एक <param> क tag provide क tag क
<applet> starting औ </applet> closing tags क क 2 attributes
attribute name attribute उ value क parameters क
pass क attribute value name attribute pass क ए naam क
value key value pair क work क
Java file parameters क include क क ए एक variable ए क क
variable क value provide क क ए एक getParameters() method क क
method उ parameter क pass क , क value variable store क
method उ parameter क value variable store क क उ
138. Classes Explanation
Button class क object create क क एक button create क क
Check-Box class check-box ए क क ए क
Choice class एक drop down menu ए क क
Label class क object ए क क एक label ए क क
List class एक list create क क
Containers क components क configure क क क components क
background color change क क ओ उ क size क क क क क ए
AWT library methods provide क methods क components क
application क according configure क क
Method Explanation Example
setBackground(color) component क
background color change क क
setBackground(red);
resize(height,width) method component क size
क क क क
resize(30,80);
move(int,int); method component क
dynamically move क क
move(50,120)
setBounds(int,int,int,int) method component क
starting position set क
setBounds(30,150,200,160)
139. Frame class
Frame एक container class application औ need क according क container
क क क frame क क Frame container क title bar, menu bar
औ borders ए basic graphical applications क ए क
AWT क example frame class क क Frame class क 2 क क
क frame class क extend क क frame class क extend क क
frame class क object create क क उ क ए
class guiLabel extends Frame
{
guiLabel()
{
Label lb = new Label("This is AwT BeSt ExAmPlE");
add(lb);
setSize(200,200);
setVisible(true);
}
public static void main(String args[])
{
140. guiLabel gl = new guiLabel();
}
}
ऊ ए ए उ frame class क extend क उ क क
ए उ frame class क object क
class guiButton
{
public static void main()
{
Frame f = new Frame();
Button b1 = new Button("Click it!!");
f.add(b1);
f.setTitle("Button Example");
f.setSize(200,200);
f.setVisible(true);
}
}
141. Chapter 26
Swing
This chapter covers:
Introduction to Swing
Different Swing classes
Example
Introduction to java swing
Abstract windows toolkit क क क क क ए swing क AWT library basic
GUI controls provide क Swing AWT क advanced version AWT क 2 problems
AWT programs size
AWT components fixed , उ change क क
problems क swing remove क Swing AWT based ए swing AWT
क replace क swing क familiar swing क क क