imp java

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Java Programming

- 1 - SMS (The best friends group)

UNIT-I

JAVA

History of Java

1990:- The Sun Micro System us fup; fd;k fd ,d ,slh ubZLanguage cuk,saxs ftllss ?kjsywConsumerElectronic DevicemRiknksa dk fuekZ.k vklkuh ls gks ldsaA ;g dk;ZJames Gosling dh v/;{krk esa fd;k x;k FkkA1991:-;g fufpr fd;k x;k fd ubZProgramming Language dk fuekZ.k Hkhoops Concept ij gh gksxkA rFkkbl ubZLanguage dk ukeOAKj[kk x;k FkkA

1992:- blTeam dksGreen Team ds uke ls tkuk tkus yxk tks fd Home Appliances dsHand MadeDevices dsControlling dk dk;Z djrh FkhA blsTouch Screen ij Hkh dke esa fy;k tkus yxkA{Team Leader = Peterson}

1993:- W.W.W. (World Wide Web) vk;k ftlds vUrZxrText Base Document dks Graphical Format esaConvert fd;k x;k rHkhGreen Team ds lnL;ksa ds }kjk ;g fufpr fd;k x;k fd ,d ubZ Hkk"kk dks dke esa ysdjTiny Program dk fuekZ.k fd;k tk,A tksInternet ij ljyrk lsExecute gks ldsa rFkk tks lHkhComputers ijvklkuh ls py ldsA bUghaTiny Programs dksApplets dgrs gSaA1994:- Green Team ds lnL;ksa us Hot Java uke dkWeb Browser cuk;k ftlus ubZLanguage dh {kerk dksc

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Java Program Structure:-(Keyword) class Hello(Class Name)

{

public static void main (String arg [])

Access specifier

{

System.out.println (Hello Java);

class Object Method

}}

Dos Mode

Compilation: - C:\jdk1.5\bin>javac Hello.java

Execution: - C:\jdk1.5\bin>java Hello

Data Type in Java

Variable Declarationclass My

{

int i;

char c;

byte b;

public display ( ){}

public static void main (String arg []){

}

}

Operators(i) Arithmetic Operator (+, -, /, *, mod, +=, -=, /= , *=)

C++Java

C

Integer Character Floating

PointBoolean

Byte1 Byte Short2byte

int4 byte Longint 8

byte

Char String

2 byte 4 byte

Float Double

4 byte 8 byte

True False

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(ii) Assignment Operator (=)

(iii) Relational Operator (>, < , >= ,

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gksrk gSaA rFkk mlh ds lkFk [kRe gksrk gSa rFkkBlockds }kjk ghVariable dkScoper; fd;k tkrk gSaA cgqr lhLanguage, Variables dsScopes dks2 Categories esadivide djrh gSaA(i) Global (ii) Local

Perl, Java esa cgqr ls Global Variable Scope dks mi;ksx esa fy;k tk ldrk gSaA Java vius&vius vyxScope: -(i) Variables Defined By Class.

(ii) Variables Defined by Methods

dks ifjHkkf"kr djrk gSaA Class ds }kjkDefine fd;s x;s Variable dh dqN Unique PropertiesrFkkAttributes gksrs

gSaA tks mls Method esaDefine Variablels vyx djrs gSaAScope ftlsMethod ds }kjkdefine fd;k x;k gSaA {}ls 'kq: gksrs gSa] rFkk mudkScope {} ds can gksus rd jgrk gSaAvr% ;g dg ldrs gSa fdJava HkhLocaloGlobal Variable dks fHkUu djrh gSaAmUgsaAccess fd;k tk ldrk gSaAScope dksNested Hkh fd;k tk ldrk gSaA

Type Conversion & Type Casting

Type Conversion & Type Casting ds ckjs esa ;fn fiNykProgramming Experience gks rks ge ;g tkurs gSa fdbuds }kjk fdlh ,d Vkbi dhValue dks nwljs Vkbi dhValue dsVariable esaAssign fd;k tkrk gSaA ;fn os nksuksTypes Compatible gSa rksComparisonrFkkConversion Automatically gks tkrk gSaA fdlh ,d Vkbi dhValuedks lnSo mls cM+s Vkbi dhValue esa ghAssign fd;k tk ldrk gSa] ijUrqdouble dksbyte esa Convert djuk gSa] rksmls Implicitly Convert ugha fd;k tk ldrk gSaA blds fy, Type Casting dh vko;drk gksrh gSa] ftlesaInCompatible Type esaConversion fd;k tk ldrk gSaA vr% Type Casting ds }kjkInCompatible Types esaExplicit Conversion fd;s tkrs gSaA

Automatic Type Conversion: -

blds vUrZxr tc ,d Vkbi ds MkVk dks nwljs Vkbi ds Variable esaAutomatic Convert dj fn;k tkrk gSa rks blizdkj dsConversion dksAutomatic Type dgrs gSaA ;gConversionrHkh gks ldrs gSa tc fuEu nks ckrsaSatisfygksrh gksa:-

(1)nksuksTypes Compatible gksus pkfg;sA(2)Source Type ftldk dhConversion fd;k tk jgk gSa] Destination Typels NksVh gksuh pkfg,A

tc ;s nksuks dkj.kSatisfy gksrs gSa] rhkhAutomatic Type dsConversions fd;s tk ldrs gSaAExample: - byte, short, int, long

Character of Boolean Type dsData dksInterchange ugha fd;k tk ldrkA

InCompatible Types Casting

TSklk fd ge tkurs gSa fdAutomatic Type Conversion vklkuh lsPerform fd;s tk ldrs gSa] rFkk osUser ds fy,

Helpful Hkh gSa] D;ksafd bl izdkj dsConversion esa fdlh izdkj dhExtra Types dh vkodrk ugha gksrh gSa] ijUrq ;fn

fdlhInteger Value dksByte Value esaConvert djuk gSa] rks ogAutomatic Conversion ds }kjk ugha fd;k tk

ldrk gSaA D;ksafdbyte, integerls NksVk gSaA vr% bl izdkj dsConversion Explicitly fd;s tkrs gSaA vr% ;g dg

ldrs gSa] fd In Compatible Type ds e/; Explicitly Conversion fd;s tkrs gSa] ftUgsa Casting of In

Compatible Types dgk tkrk gSaA vr% blds fy, Syntax fuEu gSa%&

(Target Type) ValueByte a;

int i;

a = (byte)i;

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Feature of Java

(1) Simple:- Java dksProfessional Programmers ds fy, Learning vkSj mi;ksx ds fy, vklku ekuk tkrk gSaD;ksfd ;fn ogProgram igys lsObject Oriented Conceptls tkurk gSa rksJavamlds fy, eqfdy ugha gksxhA;fnProgrammers C++ ds dqN difficult Concepts dks Hkh gVk fn;k x;k gSa] ftlds dkj.kJava vkSj Hkh vklku cutkrh gSaA(2) Object Oriented:- Java dks nwljhLanguage dh rjgSource Code ijDependjgus dh vko;drk ughagksrh gSaA bl dkj.kJava Clean, Usable, Pragmatic O;ogkfjdekuk x;k gSaA Java C++ ds dqN Concept tSls%&

Inheritance, Encapsulation, Abstraction, Polymorphism dks HkhFollow djrk gSa rFkk blesa lHkh dk;Z Objectij fd;k tkrk gSaA(3) Robust (Strong): -Robust Program Create djus ds fy, Java dks High Priority nh xbZ gSaA Java,Programs dhReliability dksMaintainj[krk gSa rFkkJava, Most Common Errors tks fdProgramming izk;%gks tkrh gSa dks Hkh Lo;a gh laHkky ysrk gSaA Java ,dStrictly Type Language gSa] tks Code dksCompile Time ijpSd djrh gSa] lkFk ghCode dksRun Time ij Hkh pSd djrk gSaA Java dksRobust cukus ds fy, nksMain ReasonfuEu gSa%&

(a) Java esaMemory Management ;kMemory dkAllocation ;kDeAllocation Virtually fd;k tkrkgSaA Allocation Completely Automatically gksrk gSaA

D;ksafdJava esaGarbage Collection Facility Available gSa] tksUnUse Objects dks ghDiscard dj nsrh gSaA(b)Mis Handled Exceptional Conditions:- Program Environment esa dqN Exception dks Java }kjk

Lo;a ghHandle dj fy;k tkrk gSaA tSls%& divide by Zero, File not Found, Exception etc.

vr% dg ldrs gSa] Java Programs dhRun Time Errors dks vklkuh lsHandle fd;s tk ldrs gSaA(4) Multi Treaded:- Java dhReal Word Requirement dksFulfill djus ds fy, Design fd;k x;k gSa ftllsJava Programs dks Internet ij vkSj Hkh Interactive cuk;k tk ldsA blds fy, Java Multi ThreadedProgramming dksSupport djrh gSaA ftlds }kjkPrograms cgqr ls Operations dks yxkrkjPerform dj ldrsgSaA D;ksafd Java bu Run Time System Multi Process Synchronization dks Support djrk gSaA ftllsInteractive System dks Smoothly Run fd;k tk ldrk gSaA Java dks Easy to Use ApproachrFkk MultiThreading ds }kjkProgram dkBehaviouroSpeed Hkh c

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Java Programming


(10) Portable: - Byte Code Conversion ds dkj.kJava dksPortable Language Hkh dgk tkrk gSa D;ksafd cgqr lsComputer ijDifferent Types dsOperating System ij Hkh vklkuh lsExecute gks tkrs gSaA ftlds dkj.k ;g,dPortable, Executable Code Generate djrs gSaA(11) Security: - Security dh nf"V lsJava Strong Language gSaA igys tc Hkh dHkhPrograms dksDownloadfd;k tkrk gSa rks muds fy, Viral Infection dh vkkadk cuh jgrh FkhA vr% cgqr ls Programmer usPrograms dksFrequently Download djuk can dj fn;kA ;kDownloadingls igys muPrograms esaVirus Scanning djmUgsaDownload fd;k tkrk FkkA Java, Normal SystemrFkk Internet ds e/; Firewall dk dk;Z djrh gSaaA tc

Java dsWeb Browsers dks mi;ksx esa fy;k tkrk gSa rksJava applets fcuk fdlhExtra DocumentrFkk fcuk fdlhVirtual Infection ds Download dj fy;s tkrs gSaA bl izdkjJava Programs dksProtections, Java dsWebBrowsers ds }kjk gh fd;k tkrk gSaA

Java Environment

Java Environment esaJava Developer dhClassesrFkkmethod dksAdd fd;k tkrk gSaA Java DevelopmentTools esaJDK (Java Development Tool Kit)rFkk lkFk ghClassesoMethod dksJava dhStandard Library(JSL) esa lfEefyr fd;k tkrk gSaA Java Development Kit esaApplet Viewer, javac , java, javap, javah ,javadocrFkkjdb dks 'kkfey fd;k tkrk gSaA JSL esa language, Input Output Packages, AWT (AbstractWindow Tool Kit) Applet Packages, Net Packages, Utility dks 'kkfey fd;k tkrk gSaA

Hardware & Software Requirement In Java

Java dhH/WrFkkS/W Requirement fuEu gSa(1)Windows95(2) IBM Compatible 486 System(3)8 Mb Memory Location(4)Windows Compatible Sound Card(5)Hard drive(6)CD ROM(7)Compatible Mouse(8)Windows95 Software

tc Java dsSource Code dksCompile fd;k tkrk gSa rksJava dkCompiler Class File cukrk gSa ftlesa ,dIntermediate Code gksrk gSa ftlsByte Code dgrs gSaA

Java Virtual MachineJava dh ogTeam ftlesaSecurityrFkkPortability nksuks leL;kvksa dksSolve dj fn;k og FkkJava Compiler ds}kjk fd;k gqvkByte Code Conversion. Byte Code Conversion Highly Optimized Set of Instruction gSa]ftlsJava Run Time System ijExecute fd;k tkrk gSaA ogMachine ftlds }kjk ml dksM dksExecute fd;ktkrk gSa] ;g JVM (Java Virtual Machine) dgykrh gSaA ljy 'kCnksa esa JVM ,d Interpreter gSa] ftllsByteCode Execute fd;k tkrk gSaA Java dsPrograms Byte Code esaConvert djus esa Programs fdlh Hkh rjg dsEnvironment esa vklkuh lsExecute gks ldrs gSaa mUgsa flQZJVM Implementation dh vko;drk gksrh gSaA JVMdh vko;drkPlatform to Platform vyx&2 gksrh gSaA rFkk lHkhByte Code dksInterpret dj ldrs gSaA bl izdkjByte Code dsInterpreterlsPrograms, Portables curs gSaAJava Programs dk InterpretationmUgsaSecurity iznku djus esa Hkh lgk;rk iznku djrk gSaA D;ksafd Java ds gj

Program dkExecution, JVM dsControl esa gksrk gSaA JVM, Programs dksSafe Environment esaExecutedjrk gS rFkk mlsSystemls feyus okysSide Effects dks Hkh cpkrk gSaAtc Java Program dksInterpret fd;k tkrk gSa] rks ogCompiled Program dh vis{kk /khjsExecute gksrk gSaA ijUrqJava esaByte Code Conversion ds }kjk rFkkJVM dh lgk;rk lsRuntime Systems ijPrograms FastlyExecute gksrs gSaA Sun Micro Systems ds }kjkByte Code ds fy, ,dJIT Compiler (Just In time) Hkh miyC/kgSa tksJVM dk gh ,dPart gSaA blCompiler ds }kjk ghByte Code Executable Code esaConvert gksrk gSa] rFkkPrograms Execute gksrs gSaA

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Java Programming


JVM

Architecture of JVM

Control Statement

(1) Simple if: -Syntax: - if (Boolean Expression)

//Which return true or false

True Statement;

False Statement;

(2) if-else: -

Syntax: - if (Boolean Expression)

True statement

else

False statement

ifrFkk if else Condition, Relational Operators dks mi;ksx esa ysdj cukbZ tkrh gSaA Boolean Expression ds

varxZrBoolean OperatorsrFkkRelational Operators dks lfEefyr dj fy;k tkrk gSaAif StatementlnSoTop to Down gksrs gSaA ;fnif Expression esa fy[kh x;hCondition True gSa rks lcls igys ogCondition Execute gksxh rFkk ckdhCondition dksSkip dj fn;k tk;sxkA

Switch Case: - Switch Case Statement, Multi Way Branch Statement gksrs gSaA ;gExecution ds ,sls rjdsdksSupport djrs gSa] ftlesa User dsSource Code dsDifferent Parts dksExpressions ds vk/kkj ijCheckfd;k tkrk gSaA ;gif else ifdhProblems dks nwj dj nsrk gSaASwitch ds varxZrExpression fy[kh tkrh gSa] ftlesa character, boolean, integer, byte etc. Data Type dhValue dks Specify fd;k tkrk gSaA case Statement esa casels Match djrh gqbZ Value dks nkkZ;k tkrk gSaASwitch Case Statement ds varxZr default Keyword dks Hkh dke esa fy;k tkrk gSaA tc case esa fy[kh xbZExpressions, True gks tkrh gSa] rkscaase dsStatement dksExecute djrs gSa rFkk lkFk ghdefault Statement HkhExecute gksrk gSaA Statement Sequence dksTerminate djus ds fy, break Keyword dk mi;ksx fd;k tkrk gSa]ftls gjcase Statement esa fy[kk tkrk gSaA

Syntax: - Switch (Expression)

{

case :

1st Statements;

break;

case :

Source Code Byte Code

Inter reter JVM

Object Code

Compile (JIT)

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2nd statements;

break;

case

n Statement;

break;

default:

}Example: -

class Switch_Case

{

public static void main (String a [])

{

for (int i=0; i

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(2)While Loop: - Conditional Statements dks rFkkConditional Expressions dksControl djus ds fy,While Loop dks mi;ksx esa fy;k tkrk gSaA ;fn izksxzke ds varxZrWhile Loop esa fy[kh xbZCondition,False gksrh gSa rksWhile Loop esa fy[ks x;s Statements dksExecute ugha fd;k tkrk gSaA

Syntax: - while (Condition)

{

// body

}

Example: - (while)class Rev

{

public static void main (String a [])

{

int n=10;

while (n>0)

{

System.out.println(n);

n--;

}

}

}Example: - (for)

class Rev

{

public static void main (String a[])

{

int n ;

for (n=10; n>0; n--)

{

System.out.println (n);

}

}}

(3)Do While Statements: - dHkh&2 ;g vko;d gks tkrk gSa fdWhile Loop esa fy[ks x;s Statements ,dckj rksExecute gks gh blfy, Do while Loop dks mi;ksx esa fy;k tkrk gSaA nwljs 'kCnksa esa tc UserTermination Condition dksTest djuk pkgrk gSa] rksDo While Loop dk iz;ksx fd;k tkrk gSaA

Syntax: - do

{

// Body of Loop

}

while (condition);

Example: - class Rev

{

public static void main (String a[]){

int n=10;

do

{

System.out.println(n);

n--;

}

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Java Programming


}

}

Example:- *****

****

***

**

*class My

{

public static void main (String str[])

{

int i,j;

for (i=0; i

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Continue Statements

dHkh dHkh izksxzke ds varxZr blLoop dksContinuej[kuk pkgrs gSa ijUrqfdlhSpecial Iteration ;kCondition dsle; mlLoop dhProcessing dks can djuk gks ;k jksduk gks rks bl izdkj ds Statements ds fy, Continue dkmi;ksx fd;k tkrk gsaA While LooprFkk Do While ds varxZr Continue Statements ds dkj.kStatementsDirectly Loop dh Conditional Expression ds ikl pys tkrs gsaA For Loop ds varxZr ;fn ContinueStatements dks mi;ksx esa fy;k tkrk gSa rks og igysIterative StatementsrFkk ckn esaConditional Expressionsds ikl esa tkrk gSaA

Example: -class My1

{


{

int i;

for (i=0;i

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Java Internet & WWW

JavarFkkInternet nksuks dksUser Interface Programming ds fy, mi;ksx esa fy;k tkrk gSaA Java ds }kjk cgqr lsFree Objects cuk;s tkrs gSa tks iwjsInternet Space ij(Cyber Space) Freely Move dj ldrs gSaA Networkij2 Categories dsObject dksServerrFkkP.C. ds chp esaTransmit fd;k tkrk gSaA

(1)Passive Information(2)Active in Dynamic Programs.

tc fdlh HkhProgram dksNetworklsDownload fd;k tkrk gSa rks og izksxzke dksM rc rdPassive cuk jgrk gSatc rd fd mlsExecute uk djsaA DynamicoActive ProgramsosPrograms gSa tksSelf Execute gksus dh {kerkj[krs gSa ,slsPrograms Client Computer ijActive Agent dk dke djrs gSaA ijUrqbuDynamic Program dsdkj.k dHkh&2 Serious Problems Hkh mRiUu gks tkrh gSaA ftudk {ks= eq[;r% PortabilityrFkkSecurity gksrh gSaAW.W.W.:- World Wide Web 1993 esa vk;kA ftlds }kjk Text Environment dks Graphical BaseEnvironment esaConvert dj fn;k x;kAWorld Wide Web ds lkFk&2 Java Developers usTiny Programscukus dh lksph buTiny Programs dksApplets dgk tkus yxkA tc rdJava dsPrograms dksWeb ds }kjkaccept ugha djk fy;k x;k rc rd www bruk izpfyr ugha gqvk FkkA Internet ij Java dks Fore FrontComputers Language dgk tkrk gSaA D;ksafdNet ij lcls T;knkPortable Program cukus dh lclsEfficeintLanguage Fkh ftl ij lHkhUser vklkuh ls dk;Z dj ldrs FksA bl izdkj Java ds }kjkNet ijPortablity dhProblem dks nwj fd;k x;kA

TokensWhite space: - Java dksLanguage Free dgk tkrk gSaA vr% ;g dg ldrs gSa fd Java esa fdlh Hkh rjg dsSpecial Indentation dh t:jr ugha gksrh gSaA fdlh Hkh izksxzke esa de ls de gjToken ds chp esa ,dWhite Spacegksuk t:jh gSaA ftls fdlhOperator, Seprator etc. dks mi;ksx esa ysdj iwjk fd;k tk ldrk gSaA Java esaWhiteSpace dksTab ;kNew Line dgk tkrk gSaAIdentifiers :- Class name, Method Name, Variable name etc. dks Identifiers dgk tkrk gSaA IdentifierUpper case Letters, Lower Case Letters, Numbers, UnderScore ;k nwljs lHkh izdkj dsCharacters dhSequence dks dgk tkrk gSaA Identifiers dHkh HkhNumber ds }kjk 'kq: ugha gksrs gSaA pwafdJava, Case SensitiveLanguage gSa vr% Upper Case/Lower Case Identifier vyx&2 gksaxsAExample:- VALUE Both are different Identifiers

value

Literals :- Java ds varxZr fdlh HkhConstant Value dksCreate djus ds fy, mldkLiteral Representationvko;d gksrk gSaA Literals dks dHkh Hkh fdlh Hkh le; mi;ksx fd;k tk ldrk gSaAFor Example: - const pi = 3.14;

Java Key Wrods: - Java esa49 Key Words dks define fd;k x;k gSa ;s Keywords OperatorsrFkkSepratorsdksCombined djds cuk;s x;s gSaA Key words dks Class name, Method name etc. ugha fn;k tk ldrk gSaA

1. abstract 18. finally 34. public2. assert 19. float 35. return3. boolean 20. for 36. short4. break 21. goto 37. static5. byte 22. if 38. strict fp6. case 23. implements 39. super7. catch 24. import 40. switch8. chare 25. instanceOf 41. syncronized9. class 26. int 42. this10.const 27. interface 43. throw11.continue 28. long 44. throws12.default 29. native 45. transient13.do 30. new 46. try

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14.double 31. package 47. void15.else 32. private 48. volatile16.extends 33. protected 49. while17.final

ConstrFkkGoto Keyword dksReserverks fd;k x;k gSa] ijUrqmi;ksx esa ugha fy;k tkrkA blKey Words dsvykokTrue/FalserFkkNull dksReserve ekuk x;k gSaA

Bit Wise Operator(1)~ : - Bitwise Unary Not (NOT)(2)& : - Bitwise & Operator (And)(3) ! : - Bitwise ! Operator (OR)(4)^ : - Bitwise XOR Operator (XOR)(5)>>: - Shift Right(6)>>>: - Shift Right 0 fill(7)

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class Lab

{

public static void main(String args[])

{

boolean t=true;

first:{

second:{

third:{System.out.println(Before the break);

if(t)

break second;

System.out.println(This is not executed);

}

System.out.println(This is not executed);

}

System.out.println(This is after second block);

}

}

}

Output: -Before the breakThis is after second break

UNIT-II

Defining The Class

Class Definition ;kClass [kqn ,d ubZData Type gSaA ,d ckj tc Class dksDefine dj nsrs gSa rks mlsObjectsds }kjk mi;ksx esa fy;k tk ldrk gSaA Class ,dTemplate gSa ftls flQZClass dsObject ds }kjk gh mi;ksx esa ysrsgSaA tc HkhClass dksdefine fd;k tkrk gSa rks mlds varxZr MkVk rFkk mu ij gksus okysOperations dhDeclarationrFkkdefinition gksrh gSaA Java ds varxZrClasses flQZ MkVk ;k mlls Related Code vyx&2 j[k ldrh gSaA Class

dksDefine djus ds fy, Class Keyword dk mi;ksx fd;k tkrk gSaA

Class Structureclass

{

instance variable1;

instance variable2;

instance variable n;

return type method name1(parameter list)

{

//body of method;

}

return type method name (n parameter list){

//body of method;

}

}

Class ds vanj define variables dks instance variables dgk tkrk gS rFkk ftrus Hkh Operations Data ijPerform fd;s tkrs gSa] mu lHkh dks Method ds varxZr j[kk tkrk gSa] vr% MethodsrFkk Variables ClassMembers gksrs gSaA

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lHkhMethods ;k lHkhClasses tks fd ,dProgram esadefine gSa] muesa ls fdlh Hkh ,dClass esamain Methoddh vko;drk ugha gksrh gSaA lkFk gh tc Applets Declare fd;s tkrs gSa rks muesamain dh vko;drk ugha gksrh gSaA

Constructors: - fdlh HkhObject dks mlds Creation ds le; gh initialize djus dk dkeConstructor }kjkfd;k tkrk gSaA Constructor, Class name gh gksrk gSaA Constructors ds vkxs fdlh HkhAccess Specifier (Public,Private etc) dks ugha yxk;k tkrk gSaA ;gka rd fdvoid dks Hkh mi;ksx esa ugha fy;k tkrk gSaA ,d ckjConstructordks Define djus ij Object Create djrs le; og Automatically Objects dks intialize dj nsrk gSaA

Constructor dh dksbZ HkhReturn Type ugha gksrh gSaA D;ksafd ogClass Type dsObjects dksintialize djrk gSa vr%Constructor dhReturn Type HkhClass Type gksrh gSaA(Constructor dk dk;Z Objects dks intialize djuk gksrk gSa rkfd Code Creation ds le; Objects Fullyinitialized gksA)Constructors dks eq[;r% 2 Parts esa ckaVk tkrk gSaA(1) Default Constructor:- Default Constructor, Object Creation ds le; Automatically invoke gksrk gSaA;g vko;d ugha gSa fd izksxzke esaDefault Constructor dksdefine fd;k tk;sASyntax: - classname objectname = new operator classname();

A obj = new A ();

tc fdlh Hkh izksxzke esaDefault Constuctor dksExplicitly Define ugha fd;k tkrk gSaA rksJava AutomaticallyDefault Constructor dks dkWy dj ysrk gSaA tc HkhDefault Constructor ds }kjkObject dksinitialize fd;k tkrkgSa] rks lHkh esa 0 Store dj fn;k tkrk gSaA Simple Classes dsDefault Constructormi;qDr gSaA

For Example: -

class Const

{

double d;


{

Const obj = new Const ();

obj.d = 20;

System.out.println (obj.d);}

}

;gka ijJava Automatically Default Constructor dksCall djrk gSaAclass Const

{

double d;

Const ()

{

d=10;

}


{

Const obj = new Const ();

System.out.println(obj.d);

obj.d=20;

System.out.println(obj.d);

}

}

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;gka ijExplicity Default Constructor dksCall fd;k x;k gSaA(2) Parametrized Constructor: - Parametrized Constructor dks HkhObject initialization ds fy, dke esafy;k tkrk gSaA Parameterized Constructor dksSet djus ds fy, dke esa fy;k tkrk gSaA mnkgj.k ds fy, ;fn izksxzkeesa Base dhValue dks Calculate djuk gSa rksParameterized Constructor dks mi;ksx esa fy;k tkuk pkfg, D;ksafdBox dk vkdkj vyx&2 gks ldrk gSaA bl izdkj dsConstructor esaObject Creation ds le; Parameters Passfd;s tkrs gSaAFor Example: -

class Box{

double height;

double width;

double depth;

Box (double h, double w, double d)

{

height=h;

width=w;

depth=d;

}

double volume()

{return height*width*depth;

}

}

class Box 1

{


{

Box b1= new Box();

double vol= b1.volume ();

System.out.println(Volume is+vol);}

}

This Key Word: - C++ dh rjg ghthis Keyword dksJava esa Hkh mi;ksx fd;k tkrk gSaA dHkh&dHkhMethod dksthis Keyword dh vko;drk iM+rh gSa tc mlMethod dks ftlObject ds }kjkPrint fd;k x;k gSa] mlhObjectdksRefer djuk gks rks blds fy, this Keyword dk iz;ksx fd;k tkrk gSaACurrent Object dksRefer djus ds fy, fdlh HkhMethod ds varxZr this dk iz;ksx fd;k tk ldrk gSaA this dksCurrent Class dsObject dksRefer djus ds fy, dgha Hkh mi;ksx esa fy;k tk ldrk gSaAFor Example: -

Box (double n; double w, double d)

{

this.height = h;

this.width = w;this.depth = d;

}

New Operator: - tc Hkh Class dk Object cuk;k tkrk gSa rks Bracket() Constructor dks nkkZrk gSAConstructor ds }kjk ;g nkkZ;k tkrk gS fd tc ,dClass dkObject Create gksxk rks D;k gksxkA vFkkZr~ ge ;g dgldrs gSa fdConstructor Object initalization dk dke djrk gSaAnew Operator ds }kjkObject dksCreate fd;k tkrk gSa ijUrqClass, Data Type tSls%& int, char, boolean etcds fy, new Operator dks mi;ksx esa ysus dh vko;drk ugha gksrh gSa D;ksafdJava ds varxZrSimple Data Types dks

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Java Programming


Object dh rjgImplement ugha fd;k x;k gSa] cfYd mUgsaNormal Variables dh rjgImplement fd;k x;k gSaAObject esa cgqr lh ,slh foks"krk,a gksrh gSa] ftlds }kjkObjectrFkkVariables esaDifferentsle>k tk ldrk gSaAnew Operator, Objects dksRuntime ijMemory Allocate djus dk dke djrk gSaA blls izksxzke dsExecutionds le; Class ds fdrus HkhObject cuk;s tk ldrs gSaA Run Time ijMemory Allocation djus ds fy, NewOperator dk mi;ksx fd;k tkrk gSaA]

Garbage Collection

Objects dksNew Operator ds }kjkDynamic Memory Allocation fd;k tkrk gSaA vr% tc HkhNew Operator

ds }kjkMemory Allocate dh tkrh gSa rks ml izksxzke dsExecutionrd gh mlObject ds iklMemory gksrh gSaAvr% ;g dgk tk ldrk gSa fdJava esa izksxzkeExecutionrd ghObjects dksMemory Allocate gksrh gSa ckn esa muObjects dsDestroy gks tkus lsMemory iqu% Reallocation ds fy, ;kMemory dk iw.kZReallocation gks ldrkgSaA C++ esaMemory dsde allocation ds fy, Delete Operator dks mi;ksx esa fy;k tkrk gSaA Java esaMemorydkde-allocation Automatically Perform gksrk gSa ogTechnique ftlds }kjk ;g dk;Z fd;k tkrk gSaA GarbageCollection dgykrh gSaAtc fdlh HkhObject dks dqN le; rd mi;ksx esa ugha fy;k tkrk gSa rksGarbage Collection ds }kjk mlObject dksDestroy djMemorydks iqu% mi;ksx esa ys fy;k tkrk gSaAC++ dh rjgJava esa Object dksExplicity Destroy djus dh vko;drk ugha gksrh gSaA Garbage Collection dsoyProgram Execution ds nkSjku gh dk;Z djrk gSaAFinalize Methods: - dHkh&dHkh tc Object dksDestroy dj fn;k tkrk gSa rc Program ds }kjk mlhObject dks

dqN Operation Perform djus ds fy, dgk tkrk gSaA ,slh ifjfLFkfr esaJava }kjk ,dMachanism Provide fd;kx;k gSa ftlsFinalization dgrs gSaA Finalization ds }kjk muSpecific Actions dksPerform fd;k tkrk gSaA tcObject Garbage Collector ds ikl igqap pqdk gksrk gSaAfdlh HkhClass esaFinalizer dksAdd djus ds fy, Finalize Method dk mi;ksx fd;k tkrk gSaA Java ijRun timeEnvironment blMethod dks rc Call djrk gSa rc Object dksDestroy djus ds fy, Garbage Collectionviuk dk;Z 'kq: dj pqdk gSaaA Finalize Method ds vanj mlOperation dks fy[kk tkrk gSa ftlsFinalize Method ds}kjk ;kObject Destroy gksus ls igysPerform djukA Garbage Collector ds }kjkPeriodically OperationsPerform fd;s tkrs gSaA Finalize Method dksClass esa fuEu izdkj lsdefine fd;k tkrk gSaASyntax:- protected void finalize ()

{

// Body of Method

}

protected Access Specifier dksFinalize dh lqj{kk ds fy, dkWy fd;k tkrk gSa ftlesaClass ds ckgj dkCodemlsAccess u dj ldsaA vr% ge ;g dg ldrs gSa fdFinalize Method dksGarbage Collector dsJust igysCallfd;k tkrk gSaAMethod Overloading:-tc fdlhClass esa nks ;k nsk ls vf/kdMethods dk ukeSame gks ijDeclaration ofParameters vyx&2 gks rks bl izdkj ds Methods dks Overload MethodsrFkk bl Process dks MethodOverloading dgk tkrk gSaA Method Overloading, Polymorphysm dk gh ,d mnkgj.k gSaAtc HkhOver loaded Methods dksinvoke fd;k tkrk gSa rc Java ds }kjk mldsArguments ;kParameters dkspSd fd;k tkrk gSaA ftllsMethod Call ds ckjs esa irk pyrk gSaA Methods dhDifferent Return Type Hkh gksldrk gSaAFor Example: -

class Method

{ void test()

{

System.out.println (Not any initialization);

}

void test (int s)

{

System.out.println (s=+s);

}

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void test (int c, int d)

{

System.out.println (c=+c+d=+d);

}

}

class Method1

{

public static void main (String str[]){

Method m1 = new Method1 ();

m1.test();

m1.test(10);

m1.test(10,20);

m1.test();

}

}

Example:-class Method

{double Area (double l, double b)

{

System.out.println(Area of rectangle is:+l*b);

}

int Area (int b, int h)

{

int a;

a = (b*h);

System.out.println (Area of triangle is+a);

}

double Area (double r){

double a;

double pi = 3.14;

a = pi*r*r;

System.out.println (Area of Circle is: +a);

}

}

class Method1

{

public static void main (String str [])

{

Method obj= new Method( );obj. Area (3.4, 4.0);

obj. Area (5, 4);

obj. Area (5.5);

}

}

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Inheritance

Inheritance Object Oriented programming ds fy, Important gSa D;ksafd og Creation of hierarchicalClassification, Java Allow Mainly Four type of interitance are follows:-

(1)Simple(2)Multi Level(3)Hierarchical

Java, Interitance esaMultiple Inheritance dh txgInterface dks mi;ksx esa fy;k tkrk gSaA

Example: - class A{

int a,b;

void display ( )

{

System.out.println (a+a+ b+b);

}

}

class B extends A

{

int c;

void display1( )

{System.out.println(c+c);

}

void sum ( )

{

System.out.println (a+b+c + (a+b+c)};

}

}

class C

{


{ A obj1 = new A ( );

B obj2 = new B ( );

obj1. a = 10;

obj1.b = 20;

System.out.println(a+b=);

Obj1.display ( );

System.out.println ( );

obj 2. a = 10;

obj 2. b = 20;

obj 2. c = 30;

obj 2. display ( );

obj 2. display ( );obj 2. sum ( );

System.out.println ( );

}

}

Inheritance, oop ds varxZr egRoiw.kZ ekuk tkrk gSa D;ksafd fdlh ,dGeneral Class ds varxZrLogically RelatedItems dks j[k dj fdlh nwljhClass ds }kjkItems dksAccess fd;k tkrk gSaA ftlClass dksInherit djok;k tkrkgSa, mlsSuper Class dgrs gSaA rFkk ftlClass dksinherit fd;k x;k gSa] ogSub Class dgykrh gSaA

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Super Key word dkUse: -dHkh&dHkhSuper Class ds varxZrDuplicate Code Hkh 'kkfey gks tkrk gSaA ftllsizksxzke Inefficient gks tkrk gSa ijUrqSub Class ds ikl fQj HkhSuper Class dsMembers dksAccess djus dhPermission gksrh gSaA ;fn dHkhSuper Class ds varxZrVairables dksPrivate Declare dj fn;k tkrk gSa rks SubClass dsObject ds }kjk muVariables dksAccess ;kinitialized ugha fd;k tk ldrk gSaA vr% oop Concept esaencapsulation dksPrimary Atribute ekuk tkrk gSaA tc Hkh fdlhSub Class dskJust viuhSuper Classls fdlhMember dks Access ;kintialize djus dh vko;drk gksrh gSa rksJava ds }kjkSuper Key word dk mi;ksx fd;ktkrk gSaA

Super Key Word dh nksGeneral Forms gksrh gSaA(1)Super Key word ds }kjkSuper Class dsConstructor dksCall fd;k tkrk gSaA(2)bl Key Wordls Super Class ds Members dks Access fd;k tk ldrk gSa ftlls Sub Class ds

Member Access ugha dj ldrs gSaA vr% ;g dgk tk ldrk gSa fd ogMember Super Class ds }kjkHidden dj fn;s tkrs gSaA

Super Class Constructor dks Super Keyword }kjkCall djuk:-dksbZ HkhSub Class, Super Class dsConstructor Method dksSuper Key Word ds }kjkAccess dj ldrh gSaASuper (Parameter List);

;gka ijParameter List, Super Class dsConstructor esaDefine Parameters dksSpecify djrk gSaA Sub ClassdsConstructor esa tks igykStatement Execute gksrk gSa ogsuper gh gSaAInheritance ds vUrxZrConstructor dks Call djuk:-tc Hkh fdlhClass esaConstructor cuk;s tkrs gSa rksigyssuper Class dsConstructor Call gksaxs] ckn esaSub Class dsConstructor dksCall fd;k tk;sxkAExample: - B ,dSub Class gSa] ftldhSuper Class A gSaA rFkk tc B Class dsConstructor dksCall fd;ktk;sxk rks igysA Class dkConstuctor Automatically Call gksxkA vr% Sub Class dsConstructor esa lclsigysSuper ds varxZr fy[ks x;sParameters dksCall fd;k tkrk gSa] tks fdSuper Class dsConstuctor dks dkWydjus dk dke djrs gSaA ;fn fdlhClass esaSuper Keyword dk iz;ksx ugha fd;k tkrk gSa rksBy Default SuperCall dsPerameter test Constuctor Automatically Call gks tkrs gSaAExample:- Class A

{

A ( )

{

System.out.println {As Constructor);

}

}class B extends A

{

B ()

{

System.out.println (Bs Constructor);

}

}

class c

{


{

B obj. = new B ( );

}

}

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Super Key dks mi;ksx esa ysdj cuk;k x;k izksxzkeClass A

{

int i;

}

class B extends A

{

int i;B (int a, int b)

{

super.i = a;

i=b;

}

void show ( )

{

System.out.println (Constructor for Super Class and i: = + super.i);

System.out.println (Constructor for sub class and i =:+ i);

}

}

class C{


{

B obj1 = new B (1,2);

obj1 show ( );

}

}

Second Use of super Class:-Class Box

{

double height, width, depth;Box ( )

{

height = -1;

width = -1;

depth = -1;

}

Box (double h, double w, double d)

{

height = h;

width = w;

depth = d;

}volume ( )

{

double vol;

vol = height * width * depth;

System.out.println (Volume of Box is + vol);

}

}

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class Box1 extends Box

{

double weight ;

Box ( )

{

super ( );

weight = -1;

}Box1 (double h, double w, doubled d, double m)

{

super (h, w, d);

weight = m;

}

}

class Box2

{


{

Box1 obj1 = new Box1 ( );

obj1.weight=20;obj1. volume ( );

System.out.println (weight of Box is + ob1.weight)

}

}

Method Over Riding:- tc dksbZMethod ftlsSubclass esaSame NamerFkkSameSingnature(parameters) ds lkFkdefine fd;k tkrk gSaA tSlk fdSuper Class esa mlMethod dksDefine fd;kx;k gSa rks ogMethod tksSub Class esadefine gSa mlsSuper Class dkOver Ride Method dgk tkrk gSaA tcOveride Methods dksSubclass ds }kjkCall fd;k tkrk gSa rks geskkSubclass dsMethod dks ghCall djrs gSaablesaSuper Class dkMethod Call ugha gksrk gSa] ;kHidden gks tkrk gSaAExample: -

class A{

int a,b;

A (int i, int j)

{

a= i;

b= j;

}

void show ( )

{

System.out.println (a and is = + (a+b));

}

}class B extends A

{

int c;

B (int i, int j, int k)

{

super (i, j);

c = k;

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}

void show ( )

{

super.show ( );

System.out.println (Value of c is+c);

}

}

class c{


{

c ob1 = new (1,2,3);

ob1.show ( );

}

}

mij fn;s x;s izksxzke esa tc Show Method dksCall fd;k tkrk gSa rks ftlClass dsObj. ds }kjk mlMethod dksCall fd;k x;k gSa] oghShow Execute gksrk gSaA ;fnSuper Class dsShow Method dksAccess djuk gSa rks bldsfy, HkhSuper Key Word dk iz;ksx fd;k tkrk gSaAclass B extends A

{int c;

B (int i, intj, intk)

{

super (i,j);

c = k;

}

void show ( )

{

super.show ( );

System.out.println (value of c is:+c);

}}

Dynamic Method Dispatch (DMD)

Method Over riding Java ds ,d egRoiw.kZConcept Dynamic Method Dispatch ij fuHkZj djrh gSaA DMD ,d,slkMechanism gSa ftlds }kjkOver ridden Methods dksRun time ij pSd fd;k tkrk gSaA vr% DMD ds }kjkJava esaRun Time Polymorphism Implement gksrk gSaA ,d vR;Ur egRoiw.kZConcept fdSuper Class dksReference }kjkCall fd;k tkrk gSaA rks Java ds }kjkRun Time ij ;g irk yxk;k tkrk gSa fd fdlClass dsOver Ridden Method dksCall fd;k x;k gSaA tc Different Type dsObjects dks Refer fd;k tkrk gSa rksOverridden Methods dsDifferent Version Call gksrs gSaA ;fnSuper Class ,dMethod Contain djrh gSa vkSj mlhdkOver Ridden Method Sub Class esa gSa rksSuper Class dsReference Variable }kjkSubclass ds fofHkUuOver ridden method dksSub Class dsObjects }kjkRefer fd;k tk ldrk gSaAClass A

{

void display ( )

{ System.out.println(As method called);}

}

class B extends A

{

void display ( )

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{ System.out.println (Bs method called);}

}

class C extends B

{

void display ( )

{ System.out.println (cs called method);}

}

class D{


{

A a1 = new A ( );

B b1 = new B ( );

C c1 = new C ( );

A r;

r = a1;

r.display ( );

r = b1;

r.display ( );

r = c1;r.display ( );

}

}

Abstract Class

;fn fdlh ,slhSuper Class dksdefine ;kDeclare fd;k tk, tks flQZClass dsStructure dks crkrh gSaA ijUrqClass dkComplete Implemantation Provide ugha djokrh gSaAbstract Class dgykrh gSA Abstract Class dksviuhSub Class ds }kjkAccess fd;k tkrk gSaA ftlesa Class dk Implementation gksrk gSaA Super Class dsMeaning full Method dk Implementation Sub Class ds }kjk fd;k tkrk gSaA User ds }kjk Lo;a dhClassLiabrary cukbZ tk ldrh gSaA ftlesaUn Common Methods dksDefine fd;k tkrk gSaA ,sls Methods ftudksSub

Class }kjkOver ride fd;k tkrk gSa] rFkkSuper Class esa flQZ muMethods dkStructure define gksrk gSa rksblds fy, Abstract Type Modifier dks mi;ksx esa fy;k tkrk gSa vr% Sub Class dhResponsibility gksrh gSa fd ogmuMethods dksImplement djsaA Abstract Class dks fuEu izdkj ls define fd;k tkrk gSaASyntax: - abstract type name (Parameter list);

dksbZ HkhClass ftlesa ,d ;k ,d ls vf/kdabstract method declare fd;s x;s gks ogClass HkhAbstract ClassgksxhA fdlh HkhClass dksAbstract cukus ds fy;sclass keywordls igysabstract yxk nsrs gSaA Abstract ClassdkObject ugha cuk;k tkrk gSaA vr% Abstract Class dksnew Operator ds }kjk initialize ugha fd;k tk ldrkAAbstract ConstructorrFkkAbstract Static Methods HkhImplement ugha fd;s tk ldrs gSaAExample: -

abstract class A

{

abstract void display ( );

void display1 ( )

{System.out.println ( ] and methods of class A);}

}

class B extends A

{

void display ( )

{ System.out.println (Bs Method); }

}

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class c

{


{

B obj = new B ( );

obj.display ( );

obj.display1 ( );

}}

Abstract MethodsoksMethods gksrs gSa ftlesaAbstract Class ds varxZr muMethod dk flQZDeclaration gksrkgSa rFkkDefinition dks mlAbstract Class dhSub Class esadefine ;kimplement dh tkrh gSa ;k djrh gSaA

Final Class

(1)Using Final: - Final Key word dks3 txgksa ij mi;ksx esa fy;k tkrk gSaA(a) ;fn nksVariables ds ukeSamej[kus gSa rksFinal Keyword dk mi;ksx fd;k tkrk gSaA(b)Final Key Word dksOver riding dh leL;k ls cpkus ds fy, Hkh mi;ksx esa fy;k tkrk gSaA

Over riding Java dk lcls egRoiw.kZConcept gSa ij dHkh&dHkhOver Ridingls izksxzke esa dqN Problems Creategks tkrh gSaA vr% fdlh HkhMethod dksOver Ride gksus ls cpkus ds fy, Final Key Word dk iz;ksx fd;k tkrk gSaAftlMethod dksOver Ride ugha djuk gSa mlds vkxs Final yxk fn;k tkrk gSaAExample:-

Class A

{

final void meth ( )

{System.out.println (Method Called);}

}

Class B extends A

{

void meth ( )

{ System.out.println (Bs Method); }

}

pwafdclass A esaMeth dksfinal Declare fd;k x;k gSa vr% mls class B esaOver Ride ugha fd;k tk ldrk gSaA blls

Compile Time Error Show gksrh gSaAJava ds }kjkMethods dks Run Time ijDynamically Call fd;k tkrk gSaA blsLate binding dgrs gSa ijUrqfinal Methods ds }kjkOver Riding dks mi;ksx esa ugha fy;k tk ldrk gSaA rFkk ,slsMethods dksCompile Timeij ghRe-solve dj fy;k tkrk gSa vr% bl izdkj dhBinding Early Binding dgykrh gSaA(c) Using Final to Prevent Inheritance: - Inheritancels cpus ds fy, Final Keyword dk mi;ksx: -dHkh&dHkhUser, class dksInherit djuk ugha pkgrk gSa vr% ,slk djus ds fy, class dksFinal Key Word ds lkFkfy[kk tkrk gSaA fdlh HkhClass dksFinal Declare djus ij mldsMethods HkhAutomatically Final Declare gkstkrs gSaA fdlh HkhAbstract Class dksFinal Declare ugha fd;k tkrk gSaA vr% Abstract vkSjFinal nksuks lkFk esami;ksx ugha fd;s tk ldrsAExample:-

final Class A

{

void math ( )

{System.out.println (method called);}

}

class B extends A//error is generated because A is final class

(a) Final Variables:- Variables dks Hkh Final Declare fd;k tk ldrk gSa ,slk djus ls ml Variable dsContents dksModify djus ls cpk;k tkrk gSaA Final Variable Declare djus ij ;gmemory esa txg ugha ysrkgSaAExample:- final int i = 10;

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final char a = A;

Understanding Static

dHkh&dHkhUser dqN ,slsClass Members dks define djuk pkgrk gSa] ftlls fcukClass dkObject cuk;s mi;ksx esafy;k tk ldsA Normally Class Members dksClass dsObject }kjk gh mi;ksx esa fy;k tkrk gSaA ,slkMemberCreate djuk ftls fcukClass dsObject }kjk mi;ksx esa fy;k tk ldsaA Static }kjk laHko gSaA tc Hkh fdlhMemberdksStatic Declare dj fn;k tkrk gSaA rks mlsClass dsObject Create djus ls igys gh mi;ksx esa fy;k tk ldrk

gSaA MethodrFkkVariables nksuks dks ghStatic Declare fd;k tkrk gSaA Static method dk lcls vPNkexamplemain method gSA D;ksafdmain dks static declare fd;k tkrk gSAblfy, blMethod dks Class dsObject Createdjus ls igys gh mi;ksx esa ys ldrs gSaA ;fn fdlhVariable dksStatic Declare fd;k tkrk gSaA rks ogVariableGlobal Variable gksxkA tc Class dsobj. dksDeclare fd;k tkrk gSa rksStatic Variable dh dksbZ dkWih ugha curhgSa cfYd iwjhClass Single Static Variable dks ghAccess dj ldrh gSaAtc fdlhMethod dksStatic Declare fd;k tkrk gSa rks mld fy, 3 Limitations gSaA(a) Static Method flQZ vkSj flQZStatic Method dks ghCall dj ldrk gSaA(b) blds varxZr mi;ksx esa fy;k tkus okyk MkVk HkhStatic ghgksxkA(c) Static dksthis ;ksuper Key Word ds }kjkRefer ugha fd;k tk ldrk gSaA

Visibility Controls

Encapsulation: -Encapsulation ,d Attribute Provide djokrk gSaA ftls Access Control dgrs gSaA

Encapsulation ds }kjk izksxzke ds Different Parts dks Control fd;k tkrk gSaA ftlds }kjk Program Class

Member dksAccess dj ldrk gSaA Access dksControl djus lsClass dsMisusels cpk tk ldrk gSaA Class

Member dks mudsAccess Specifier ds vk/kkj ij Access fd;k tk ldrk gSaA Java ds }kjk fofHkUuAccess

Spedifier dksProvide djok;k x;k gSaA

Java ds Access Specifier: -

(1)Public(2)Private(3)Protected

Java ds }kjkDefault Access Level dks HkhProvide djok;k x;k gSaA Protected dks rHkh mi;ksx esa fy;k tkrk gSaA

tc Inheritance dks mi;ksx esa fy;k x;k gSaA

tc Public Access Specifier dks dke esa fy;k tkrk gSa rks mlClass ;kMethod ds varxZr fy[kk x;k dksM fdlh

HkhClass ;kMethod ds }kjkAccess fd;k tk ldrk gSaA Main Method dks lnSoPublic Access Specifier ds

}kjk dke esa fy;k tkrk gSaA ;fn dksbZ HkhAccess Specifier Use esa ugha fy;k x;k gSaA rksBy DefaultogClass ;k

Method Public gksrk gSaA

tc Hkh fdlhMember ;kClass ds vkxsPrivate Access Specifier yxk;k tkrk gSaA rks mlClass dsMember

}kjkAccess ugha fd;k tk ldrk gSaA

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UNIT - III

Arrays

,d gh MkVk Vkbi dh fofHkUuValues dks ,d ghContigious Blocks esa LVksj djuk gharrays dgykrs gSaA Array,d ghType dsVariables dkGroup gSa ftls ,dSingle ;kCommon Name ds }kjk tkuk tkrk gSaA fdlh HkhData Type dsarrays dksDeclare fd;k tk ldrk gSa rFkk mlds ,d ;k ,d ls T;knkDiemension Hkh gks ldrs gSaArray dh fdlh HkhValue dks mldh Index Value ds }kjk tkuk tkrk gSaA Related Information dks ,d lkFk

Group djds j[kus dkArray Best Option ekuk tkrk gSaA

One Diemensional Array (1-D Array)

1-D Array dksDeclare djus ds fy, lcls igys ,darray type dkVariable Declare djuk gksrk gSaASyntax: - data type arrayvariable name [];

;gka ijType array dhBase Type gSaA Variable name array dkname gSa rFkkSquare Brackets esaarray dhLength dksDeclare fd;k tkrk gSaA tc Array dhValue dks initialze djuk gks rks new Keyword dk mi;ksxfd;k tkrk gSa] tksarray dksMemory Location Allocate djrk gSaASyntax: - arrayname = new type [size];

For Example: - int month [];

month = new int [12];

Example: - Class A{


{

month = new int [12];

month [0] = 31;

month [1] = 28;

month [2] = 31;

month [3] = 30;

month [4] = 31;

month [5] = 30;

month [6] = 31;month [7] = 31;

month [8] = 30;

month [9] = 31;

month [10] = 30;

month [11] = 31;

month [12] = 30;

System.out.println (April has+month [3]+ days);

}

}

2 D Array:- Java esa nks ;k nks vf/kdarrays dks HkhDeclare fd;k tk ldrk gSaA bUgsaarray of arrays Hkh dgrsgSaA

Syntax: - int month [ ] [ ];month = new int [4] [5];

String:- tc String Object dksCreate fd;k tkrk gSa rks tksString Create gksrh gSa mlsChange ugha fd;k tkldrkA ,d ckj tc String Object Create gks tkrk gSa rks mlsCharacter esaChange ugha dj ldrs gSaA String dh,d Class ;k Super Class String Buffer gksrh gSa ftlds }kjk StringrFkk String Buffer nksuks Classes,java.lang ds varxZrdefine dh xbZ gSa tksPrograms dksAutomatically Provide gSaA nksuksClasses dks final

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Declare fd;k x;k gSa vr% ogka nksuksClasses inherit ugha gks ldrh gSa nksuksClasses ,dSingle Interface dksmi;ksx esa ysrh gSa ftls char Sequence dgk tkrk gSaA

String Constructors

String Class esa fofHkUuConstructors dksdefine fd;k x;k gSaA tc Hkh fdlhEmpty String Object dksCreatedjuk gks rksString dkDefault Constructor Use esa fy;k tkrk gSaASyntax: - String s = new String ( );

blh izdkj tc fdlhObject esainitial Value dks ikl djuk gks rks blds fy, Hkh fofHkUuConstructors dks mi;ksx esafy;k tkrk gSaA ;fn String Object dks Array of Characters ls initialize djuk gSa rks mlds fy, fuEuConstructor dks mi;ksx esa ysaxsASyntax: - String (char are []);

Exmaple: - char arr [] = {a, b, c, d};

String a = new string (arr);

blh izdkj tc fdlhCharacter Array dhSub Range initialize djuk gks rks fuEuConstructor dks mi;ksx esafy;k tkrk gSaAString (char arr [], int start Index, int num char);

Char arr [], {a, b, e, d, c, f};

String a new string (arr, 2, 3,);

Output // a=cde

Example: -Class Cha

{

public static void main (string str [])

{

char arr []={D, E, L, H, I};

String a = new String (arr);

System.out.println (The string inputted is + a);

}

}

//Output: The string inputted is DELHI

Java dhCharacter Data Type 16 Bit Unicode Character Set dksRepresent djrh gSa rFkkString Arrays ds8 bit bytes dksASCII Character set esaRepresent djrh gSaA String Class ds }kjk dqN ,slsConstructors dks HkhProvide djok;k x;k gSa tks ,dByte Array dksString esa Convert dj nsrh gSaAString (byte arr []);

String (byte arr, int start Index, int num char);

Example:- Class Chars

{

public satic void main (String str [])

{

byte arr []={65,66,67,68,69,70};

String a=new String (arr);

String a1=new String (arr,2,3);

System.out.println (The string is+a);System.out.println (The string a1 is + a1);

}

}

//Output: - The string a is ABCDEF

The string a1 is CDE

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String Length:- String Length Calculate djus ds fy, length Method dks dke esa fy;k tkrk gSaA fofHkUuString Operations, Java ds }kjk define Methods dks mi;ksx esa ysdj gh Perform dj fy;s tkrs gSa] ftlesaConcatenation Operations eq[; gSa ftls + Operator ds }kjk Perform fd;k tk ldrk FkkA StringConversion esa Java, String Operatoin dks Concatenation Operator ds }kjkConvert dj nsrh gSaA Java dsvarxZrAutomatic Concatenation Operation Perfrom gksrk gSaA ijUrqblOperation dksPerform djus ds fy,String Conversion ds fy, Call djrk gSaA Java ds varxZr lHkhClasses dhSuper Class, Object ClassgSaA vr%String Class Object dhSubclassrFkkvalueOfMethodmlString Class dk ,dOverloaded Method gSaA

valueOfMethod ds }kjkUser Readeble Data Return fd;k tkrk gSaA ftlsUser }kjkCall fd;k tkrk gSaAObjects ds fy;svalueOfmethod,dvU; method toStringdkscall djrk gSA toString methodmlclass}kjk create fd;s x, String objects dks represent djrk gSA gjString Class }kjk toString method dksImplement fd;k tkrk gSa tksObject Class esadefined gSaA User ds Lo;a dsString Representation ds fy,toString dks dke esa fy;k tk ldrk gSaA ijUrqmls Override djuk vko;d gSaAfofHkUuCharacter Operation fuEu gSaA(1)charAt():- blMethod ds }kjkSingle Character dksRepresent fd;k tkrk gSaA blesaString esa ls fdlh ,dCharacter dksAbstract djrs gSaA

String s = abc;

s.charAt(1);

output = b

(2) getChar( ):-;fn ,d ls T;knkCharacters dks fdlhSingle String esa lsAbstract djuk gks rksget Char dkmi;ksx fd;k tkrk gSaA Get Character Method }kjkSource StartrFkkEnding Point define fd;k tkrk gSaA lkFkghCharacter Array ftlesaNumber of Character dks j[kk tk;sxk rFkk tgka muCharacters dksCopy djuk gSamlTarget dks j[kk tkrk gSaASyntax: -

getChar(Starting Index, end point, target array, target Index);

s= Thid is new cap;

int start = 9;

int end = 11;

char a [] = new char (Start_end);

s. getChar (Start, end, a, o);

Example: -class String

{


{

string s = This the new demo class:;

int start = 14;

int end = 17;

char buf [];

buf= new char (start_end)

s.getChar(start, end, buf, 0);

System.out.println (buf);

}

}

(3) getBytes( ):-getBytes() Method dksgetChars ds }kjk LVksj fd;s x;s Character ArraylsByte Array esaConvert djus ds dke esa fy;k tkrk gSaA vr% Get Bytes esaByte Array dks LVksj fd;k tkrk gSaA By DefaultCharacters dksBytes esaConvert dj fn;k tkrk gSaA

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String Comparison Method

(1) equals( ) and equalsIgnoreCase:-tc Hkh nksString dksCompare djuk gks rksequals( ) dks iz;ksx esafy;k tkrk gSaA equals( ) Method Boolean Value dksReturn djrk gSa rFkkParameters esaString, Object ysrkgSaASyntax: - boolean (Object String)

equalsIgnoreCase Method esaComparison String ds e/; gh gksrk gSa ijUrqCase dksIgnore ( ) dj fn;k tkrkgSaA

Syntax: - boolean equalsIgnoreCase (Obj. String)Class Stringmet

{


{

String s1 = Hello;

String s2 = My;

String s3 = Dear;

String s4 = HELLO;

System.out.println (s1+equals+s2+s1. equals (s2));

System.out.println (s1+equals+s3+s1.equals (s3));

System.out.println (s1+equals+s4+s1.equalsIgnoreCase (s4));

}}

(2) compareTo ( ):-tc Hkh nksStrings esa ls ;gCheckdjuk gks fd dkSulhString greater than, less than ;kequals gSa] blds fy, compareTo Use fd;k tkrk gSaA blesa Strings dksDictionary Order esa pSd dj ;g crk;ktkrk gSa fd dkSulhString Less than gSa vkSj dkSulhequals.compareTo Method ds }kjkinteger value dksReturn fd;k tkrk gSa rFkkParameters esaString Pass dh tkrhgSaASyntax: - int compareTo (string str[])

Searching String:- String Class ds }kjk nks Methods Provide djok;s tkrs gSa ftuls String SearchOperation Perform fd;s tkrs gSa igyk

(1)IndexOf () Method(2)LastIndexOf () Method.

indexOf Method:-blMethod ds }kjkCharacter ;kString dh ;kSub String dhFirst Occurrence dksSearch fd;k tkrk gSaAblfy, indexOf Method integer Return djrk gSa rFkkParameters esaCharacter ;kString dks mi;ksx esa ysrkgSaASyntax: - int indexOf (int ch/string str[])

Str ds varxZrSub String Mkyh tkrh gSaAExample:- Class My

{


{

String s = Hello my dear;System.out.println(s);

System.out.println (indexOf (m) + s.indexOf (M));

System.out.println (Last Index of (M) (my)+s.lastIndexOf (m, 10));

}

}

lastIndexOf Method:-blds }kjkCharacter ;kSub String dhLast Occurence dksFindout fd;k tkrk gSaASyntax: - int lastIndexOf (String str, int start index)

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String Modification Method

(1) subString: - String ds fdlh NksVs ls Hkkx dks Extract dj ysukSub String ds }kjk gh fd;k tkrk gSaASyntax: - String subString (int start index) start index esasub string dgka lsstart gksxhAddress fn;k tkrkgSaA(2) concate( ):-tc nksstring dksconcate djuk gks ;k tksM+uk gks rksconcate method dk iz;ksx fd;k tkrk gSaeq[;r% blds fy, + Operator dks gh mi;ksx esa ysrs gSaA

Example: - String s1 = new;String s2 = s1.concate(Delhi);

//Output = new Delhi

Concate Operator dks+ Operator dh rjg Hkh mi;ksx esa fy;k tkrk gSaAExample: - String s1 = new;

String s2 = s1+ Delhi;

//Output = new Delhi

(3) replace ( ):- Replace Method esa ;fn fdlhCharacter dh txg fdlh nwljsCharacter dks j[kuk gks rks bldksmi;ksx esa ysrs gSaASyntax: - String replace (char orignal, char replace)

Example: - String s = Amit.replace (A, su);

Output sumit

(4) trim ( ): - Remove White Space(5) toUpperCase ( ):- String dks Upper Case esaConvert djus ds fy,(6) toLowerCase ( ):- To Convert the String in Lower Case.

;gMethod String Return djrs gSaA(7) reverse ( ):- String Buffer esa mifLFkrString dksReverse djus ds fy, String Reverse Method dk iz;ksxfd;k tkrk gSaAExample: - StringBuffer s = new StringBuffer (This);

s. reverse ( );

System.out.println(s);

fdlh Hkh miuke(alias) dks mldhSuper Class esaConvert djuk gks rks blds fy, Wrappers Classes dks mi;ksxesa fy;k tkrk gSaA

Wrappers

Java, Simple Data Types dks mi;ksx esa ysuk gSa tSlsint, char, etc. ijUrq;sData Types Objects dh Js.kh esa ughavkrs gSa ge tkurs gSa fd lHkhClasses dhSuper Class, Object Class gSa rFkk mlObject Class esaSimple DataType dksdefine ugha fd;k x;k gSaAbu lHkhSimple Data Types ds fy, Object Class esa vyx&2 Classes dksdefine fd;k x;k gSaA(1) Number Class: - Number Class ,dAbstract Class gSa ftlsNumeric Data Type dhSuper ClassKey dgk tkrk gSaA Numeric Data Types ds varxZrByte, Short, integer, long, double etc. dks 'kkfey fd;ktkrk gSaA Number Class ds }kjk dqN Abstract Methods Hkh Provide fd;s x;s gSa ftllsObject Value dksDifferent Number Formats esaConvert fd;k tk ldrk gSaA tSls%& Double Value Method ds }kjkDoubleType dhValue dksdefine fd;k tkrk gSaA blh rjg lHkhNumeric Data Type ds fy, ,slsAbstracts Methodsdksdefine fd;k x;k gSaA

byte byteValue ( )

int intValue ( )long longValue ( )

short shortValue ( )

float floatValue ( )

double doubleValue ( )

buMethods ds }kjkReturn gksus okyhValue Rounded gksdj iznfkZr gksrh gSaA(2) Double & Float : - Floating Point Data Type ds fy, Wrappers, FloatrFkkDouble esa tc HkhFloat ;kDouble Value dks Call djuk gks rks mlds fy, budsConstructor dksCall djuk iM+rk gSaA

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For Example: - float (float no)

double (double no)

Double Objects dksDouble Value ds }kjkConstruct fd;k tkrk gSaA Float vkSjDouble esa fuEuConstants dkslfEefyr fd;k x;k gSaA(a.) MAX_VALUE

MIN_VALUE

NAN= Not a Number

POSITIVE_INFINITYNEGATIVE_INFINITY

TYPE The Class Object of float & Double

(3) Void Class:- Void Class esa ,d Field gksrk gSa Type ftlesa Void Type dh Class ds Object dkReferencejgrk gSaAVectors: - Vector Class ds varxZrClass dsObject dksStore djds j[kk tkrk gSaA ;g fcYdqyArrays dh rjggh dk;Z djrs gSA blesa HkhObject Contigous blocks esaStoredjgrs gSa bUgsaDynamic Array Hkh dgk tkrk gSaA ;garray list ds leku gh gksrs gSa ijUrqeq[; nksdifference gSa%&(1) Vectors Syncronized gksrs gSa vr% ;g fdlhFramework Collection dkPart ugha gksrs gSa Java Tool dsvarxZrVectors dksAbstract List ds }kjkextend fd;k tkrk gSaA Vector Class ds }kjk fofHkUuConstructorsProvide fd;s x;s gSa tks fuEu gSa%&(i) Default Constructor Vector ( )

(ii) Vector (int size)(iii) Vector (int size, int increment)

(iv) Vector (Collection c )

Default Constructor eSaBy Default 0 Value dksInsert dj fn;k tkrk gSaA nwljs izdkjConstructor esaVectordh initial Catrgory dksSize esa iznfkZr fd;k tkrk gSaA Third Type Vectors esaSizerFkk Increment nksuks dksSpecify fd;k tkrk gSaA Increment Vector ds varxZr fdlhSpecificle; ij fdrusElements dksStored djsxkAbls izfnkZr fd;k tkrk gSaA Fourth Type Constructor esaCollection Element dks j[kk tkrk gSAInterfaces:- Interface Keyword Fully Abstract Class ds fy, mi;ksx esa fy;k tkrk gSaA Interface dks tcfdlhClass esa mi;ksx fd;k tkrk gSa rksClass dks D;k djuk pkfg, ;gInterface esa ghdefine dj fn;k tkrk gSa ijUrqdSls fn;k tk;sxk ;g Specify ugha fd;k tkrk gSaA Interface, Classes dh rjg gh gksrs gSaA ijUrq buesa InstantVariablerFkkMethod dks Declare fd;k tkrk gSa ijUrqmudhBody dksdefine ugha fd;k tkrk gSaA vr% ;g dg

ldrs gSa fd Interfaces esa flQZ VariablerFkk Methods dks Declare fd;k tkrk gSaA Interfaces esa DefineMethod dks gjClass ds }kjk mi;ksx esa fy;k tkrk gSA Java ds }kjk tc interface Keyword dksProvide fd;kx;k rks bldk vFkZOne Interface, Multiple Method vr% Fully Utilize fd;k tk ldrk gSa ftls Polymorphismds varxZr lfEefyr fd;k x;k gSaAInterfaces dksDynamic Resolution ;kRuntime Support ds fy, Design fd;k tkrk gSaA Interfaces MultipleInheritance dh rjg gh dke esa fy;k tkrk gSaA Interfaces dks ju Vkbe ij vkus okyhProblems dks nwj djus ds fy,gh Design fd;k x;k gSaA Interfaces dks Classesls vyx define fd;k tkrk gSaA rFkk ,d gh interface dksDifferent Classes esaImplement fd;k tk ldrk gSaADefining Interface:- Interfaceslcls T;knkFunctionality ftlsApplications }kjkRequire fd;k tkrk gSa dksprovide djrs gSa ftl rjgC++ esaMultiple Inheritance use esa fy;k tkrk gSa mlh izdkjJava esaInterfaces dksmi;ksx esa fy;k tkrk gSaA Interface fdlhClass esa fuEu izdkj lsdefine fd;k tkrk gSaA

Syntax: - access interface name{type return type name (Parameter List);

type return type method name (paramenter list);

type final variable name = value1;

}

;gka ij Access Specifier Public Hkh gks ldrk gSaA ;k public ;fn u yxk;k x;k gks rks Hkh Interface dksImplement fd;k tk ldrk gSaA ijUrq;gka ijInterface defining dk vFkZ vyx&2 gks tkrk gSaA

(1) ;fn Public Keyword Use esa u fy;k x;k gks rks Interface flQZ mlh Package ds Member }kjkAccess fd;k tk ldrk gSa vU; dksbZ HkhPackagemlInterface dks mi;ksx esa ugha ys ldrk gSaA

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(2) ;fnInterface dksPublic define fd;k gSa rks mls ckgj ds fdlh HkhPackage }kjk mi;ksx esa fd;k tk ldrkgSaA

Interface name ;gka ij dksbZ Hkh Valid identifier gks ldrk gSaA Interface esa define fd;s x, Method flQZDeclare fd;s tkrs gSa mudhDefinition dksInterface esadefine ugha fd;k tkrk vr% Methods dksParameterList ds cknSemicolumn (;) yxkdjShow fd;k tkrk gSaA gjClass ftlesaInterface dksInclude fd;k x;k gSamlesaInterface ds lHkhMethods dksImplement djuk vko;d gksrk gSaAVariables dks HkhInterfaces esaDeclare fd;k tk ldrk gSaA ijUrqosVariables Implicitly final vkSjstaticgksrs

gSa ftUgsa fdlh Hkh Interface Implementing Class ds }kjk Change ugha fd;k tk ldrkA lkFk gh mUgsa fdlhConstant ValuelsInitialize djuk Hkh vko;d gksrk gSa lHkhMethods vkSjVariable By default public gksaxs;fnInterface dkspublic Declare fd;k x;k gSaA

Implementing Interfaces

Interface dks ,d ;k ,d ls vf/kdClass esa HkhImplement fd;k tkrk gSaA ftl izdkj ,d ;k ,d ls vf/kdClassesdks inherit djus ds fy, extends Keyword dks mi;ksx esa ysrs gSa mlh izdkj tc Interface dks fdlhClass esainherit djuk gks rks mlds fy, implements keyworddk mi;ksx fd;k tkrk gSaA ,d ghinterface dksMultipleClasses esa Implement fd;k tk ldrk gSaA ;fn nks vyx&2 Interface dks ,d ghClass esaimplement fd;k tkldrk gSaA

interface A1

{ // static final keyword is used for variables

} // Declaration of methods

interface A2{//final static keyword is used for variables}

class A3 implements A1, A2

{ //class Body}

interface Area{

static final float pi = 3.14;

public void show ( );

}

class Rectangle implements Area

{float i, b;

void show ( )

{System.out.println (l*b+l*b);}

}

class Circle implements Area

{

float r;

void show ( )

{System.out.println (Area of circle is+pi*r*r);}

}

class Area1{


{

Area ref;

Rectangle r = new Rectangle ( );

Circle c = new Circle ( );

ref =r;

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System.out.println (Area of rectangle is+ref.show ( ));

}

}

interface Area

{

static final float pi = 3.14;

public void show ( );

}class Rectangle implements Area

{

float i, b;

void show ( )

{System.out.println (l*b+l*b);}

}

Extending Interaces: -tc ,dClass dks nwljhClass esainherit fd;k tkrk gSa rks mlhClass esaInterface dksImplement gh fd;k tk ldrk gSaA ge tkurs gSa fd Interface esa final static Variables rFkk MethodDeclaration gksrs gSa rFkkClasses esa tc bu Interfaces dksuse esafy;k tkrk gSa rks gjClass esaMethod dh ubZDefinition gksrh gSa vkSj tc Class dksInherit fd;k tkrk gSa rksClass dh lHkhProperties Derived Class esa vk

tkrh gSaAExample:-

interface A1

{// static c final keyword is use for variable.

} // Declaration of methods

Class A

{

int i. b;

public void show ( )

}

class B extends A implements A1

{ // class body}

Packages:- Different Classes dks fdlh ,dSingle Class esa Access djus ds fy, lHkhClasses dks ,dGroupesa j[k fn;k tkrk gS a ftls Package dgrs gSaA Package dks fdlh HkhClass ds }kjk mi;ksx esa fy;k tk ldrk gS a bldsfy, import Keyworddk iz;ksx djrs gSaA Java Library esa HkhMain 6 PackagesdksDefine fd;k x;k gSa ftlesaNumber of Classes vkSjMethod dksInclude fd;k x;k gSaAPackage dhClasses dks rFkkMethods dks nks rjg ls mi;ksx esa fy;k tk ldrk gSaA

(a) Package dh gh fdlhClass ds varxZr(b)User ds }kjk cukbZ xbZExternal Class

tc Package dh fdlhClass ;kMethod ds vkxsPublic Keyword dks mi;ksx esa fy;k tkrk gSa rks muClasses dksPackage ds ckgj okyhClass ds }kjk Hkh mi;ksx esa fy;k tk ldrk gSaA vkSj ;fnPublic Keyword ds vanj okyhClasses gh muMethodoClass dks iz;ksx esa ys ldrh gSaA vr% Package Private vkSjPublic nksuksa rjg ds dk;Z

dj ldrk gSaA Packages esaProtected Keyword dk mi;ksx Hkh fd;k tk ldrk gSaA

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Javas In builts Packages

JAVA Super Class

(1)Lang: - Lang Package Automatically gjClass ds fy, Import gksrk gSa blslanguage Package Hkhdgk tkrk gSaA ftlesaJava dhLanguagelsRelatedlHkhCommands, ClassesrFkkMethod definefd;s x;s gSa ftUgsajava Language }kjk mi;ksx esa fy;k tkrk gSaA

(2)Util: - Util Utility Package gSa ftlesa Languages dhUtility dksdefine fd;k x;k gSaA ftrus HkhUtilityCommands ftUgsa Java }kjk iz;ksx esa fy;k tkrk gSaA muds fy, blPackage esa fofHkUu ClassesrFkkMethods define fd;s x;s gSaA

(3)Net: -tc Java ds Applications Programs esa Socket Programming ;k Remote ServerProgramming tSlsConcepts dks mi;ksx esa fy;k tkrk gSaA rc net Package dk iz;ksx fd;k tkrk gSaA blPackage esa lHkh rjg dhNetworkinglsRelated ClassesoMethod dks lfEefyr fd;k x;k gSaA

(4)Applets: - Internet ij ftu NksV&2 Programs dksJVM dh lgk;rk lsDynamically Run fd;k tkrkgSa mUgsa Applets dgrs gSaA AppletlsRealtedlHkhMethod vkSjClasses dks ftlPackages esa j[kk tkrkgSaA mls ghApplet Package dk uke fn;k x;k gSaA vr% Appletsos lHkhCommands, Applet Package esadefine gksrs gSaA

(5) i/o: -Java esaInput/outputlsRelatedlHkhClassesoMethod dksI/O Package esa j[kk x;k gSaA(6)awt: - awt, Java dsPackage dk lcls egRoiw.kZ Package ekuk x;k gSa] ftlesa Window dh rjgDialog

Boxes, Button, Labels etc.lHkh dhFacility Available gSaA vr% blPackage dksAbstract WindowTool Kit Hkh dgk tkrk gSaA awt Package, Window Programming ls RelatedlHkh ClassesoMethods dksdefine djrk gSaA

Creative Packages

(1) System Package: -Packages dks Hierarchy Structure esa define fd;k tkrk gSaA tSls%& Java, awt

Package dks Contain djrk gSa] ftlesaGUIls lacaf/kr lHkhClasses dksImplement fd;k tkrk gSaA

Representation of Hierarchy of Java.awt Package

Packages dksAccess djus ds fy, nks rjhdksa dks viuk;k tk ldrk gSaA(1) Package ds lkFk ftlClass dks mi;ksx esa fy;k tk jgk gSaA mldk iwjk uke ftls Operator ds }kjk vyx&2fd;k tk ldrk gSaA mnkgj.k ds fy, ;fnColor Class dksImport djuk gSa rks fuEuSyntax fy[kk tk;sxkAimport java.awt.Color;

awt ,dPackage gSa ftls Java Package dkSub Package Hkh dgk tkrk gSa blApproch dks rHkh mi;ksx esa fy;ktkrk gSa tc awt dh flQZ ,d ghClass dks Access djuk gks ij dHkh&2 tc User awtlsRelatedlHkhClasses dksiz;ksx esa ysuk pkgrk gks rks mlds fy, fuEuSyntax dks mi;ksx esa fy;k tkrk gSaA

Packages

Lang Util net applets I/O awt

Java - Packages

Color

Gra hics

Ima e

awt Sub Package

Awt Contianer Classes

Awt Contianer Method

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import java.awt.*;

bu lHkhDeclarations dks izksxzke dsTop ij fy[kk tkrk gSaAPackages, Java dsNaming Packages dh 'kq:vkrLower Case Letters ds }kjk ftllsClass dhName vkSjPackage esa varj fd;k tk ldsA vr% ;fn fdlh izksxzke esa Packages dksdefine djuk gks rks blds fy, fuEuSyntaxiz;ksx esa fy;k tkrk gSaAdouble y = java.lang.Math.sqrt (x);

Package SubPackage Class Method

Packages dks Bhd izdkj ls iz;ksx ysus ds fy, ;g vko;d gSa fd gjPackage dksUnique name fn;k tk,A ;fn nksPackages dk ukeSamej[kk tk,xk rks bllsRun Time Error dh laHkkouk,a c

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blesa tks HkhSource File curh gSaA mlsSubdirectory esa LVksj fd;k tkrk gSaA vc ;fnpackage1 dks fdlh nwljhClass esaImport djuk gks rks mlds fy, fuEuSyntax gSaAimport package package1;

public class B

{


{

A obj = new A ( );obj.display ( );

}

}

tc ClassB dks Compile fd;k tkrk gSa rksCompiler dksPackage1 esa mifLFkrA Class File dks mi;ksx esa ughafy;k tkrk gSaA blds fy, Package1. class file dh vko;drk gksrh gSaA tc package1 dks ju fd;k tkrk gSa rkspackage1.class file dks nwljhclasses Hkh bls vklkuh lsaccess dj ldsaA

Import Classes from Other Packages

nwljsPackages }kjk Hkh dqN Classes Provide djok;h tkrh gSa ftUgsaUser dhClasses esa Import fd;k tk ldrkgSaA ;fn nkspackages dks ,d lkFk iz;ksx esa ysuk gSa rksJava ;gFacility Provide djrh gSaAFor Example: -

import program

import package.pakage1;import pakcage2. *;

class A

{


{

A ob1 = new A ( );

B ob2 = new B ( );

ob1.display( );

ob2. display ( );

}

}fdlhPackage esaClass dksAdd djuk%& fdlh HkhClass dkspackage esaAdd djuk cgqrSimple dk;Z gksrk gSaAFor Example: - Package p1;

Public class A;

{ // Body of A;

}

tc Hkh fdlh package esa fdlhClass dksAdd fd;k tkrk gSa rks mlClass ds vkxs public Keyword yxkukvko;d gSaA ;fnPackage p1 esa gh vU; Class B dksAdd djuk gks rks blds fy, fuEuSteps dks Follow djukgksxkA

(1)Class dkspublic define djukA(2)Class definitionsls igys package statement dks iz;ksx esa ysukA(3)B.java File dksDirectory P1 esa LVksj djukA(4)B.java File dksCompile djus ls tksClass File cu jgh gSa mls HkhDirectory p1 esa LVksj djukA

blh izdkjNon-public Class dks Hkhpackage esaAdd fd;k tk ldrk gSaA ;fnMultiple Classes dks Packagecuk gqvk gks ftlesa lHkhClasses Public gks rks blds fy, fuEuStep dks iz;ksx esa fy;k tkrk gSaA

(1)Package Name define djukA(2)Directory ds vanj ,dSub Directory cukuk vkSj mlesa lHkhSource File dks LVksj djukA(3)Package ds varxZr vkus okyh lHkhClasses dks vyx ls LVksj djuk rFkk lcls igysPackage Statement

define djukA

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(4)Sub Directory esa tkdj gjSource File dksCompile djukA ftlls mlhDirectory esaClass FileStore gks tk,A

Hiding Classes

tc Hkh fdlhPackage dksImport fd;k tkrk gSaA rks mlds lkFk esaAsterisk (Star) dk iz;ksx fd;k tkrk gSa ftllslHkhpublic Classes Import gks tkrh gSaA ;fn dqN ,slhClasses ftUgsa User hide djuk pkgrk gks rks mUgsaNon-Private Public define fd;k tkrk gSa ftlls package import djus ij Hkh osClasses import ugha gksrh gSaA vr%tc Hkh fdlhClass dks Public define fd;k tkrk gSa rks mlClass dks lHkhUsers }kjk ;k lHkhApplications

Programs }kjk mi;ksx esa fy;k tk ldrk gSaA

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UNIT - IV

Multi Treaded Programming

age tkurs gSa fdWindows is Operating System Several Programs dks Simultaneousy Execute djrk gSa blsMultiTasking dgk tkrk gSaA ij tc System Point of Viewls ns[kk tk, rks Programs Hkh One by oneInstructions dks Follow djrs gq, Execute gksrs gSa bl Concept dks Multi Treading dgk tkrk gSaa MultiTreading ,d dkYifudProgramming Concept gSa tgkaPrograms (Process) dksSub Parts esa(Sub Process)esa divide fd;k tkrk gSaA rFkk lHkhProcess Parallel implement gksrs gSaA

Example: -,dSub Programs Screen ijAnimation iznfkZr djrk gSa rks nwljk rc rd nwljsAnimation dksDisplay djus dh rS;kjh djrk gSa vr% ;g dgk tk ldrk gSa fd ,d dk;Z dks cgqr ls NksVs&NksVs dk;ksZ esa foHkkftr fd;kx;k gSaA rFkk gj NksVk dk;Z ,d vyxUser ds }kjkIndependentlyoSimultaneously perform fd;k tkrk gSaAJava Programs SinglerFkkSequential Flow Control ij dk;Z djrs gSaA blesaPrograms dksSequentiallyExecute fd;k tkrk gSaAThread, Hkh izksxzke tSls ghSingle Flow Control ij dk;Z djrs gSaA Threads dhBeginning, BodyrFkkendinggksrh gSaA Thread Body dksSequentially Execute fd;k tkrk gSaA fdlh Hkh izksxzke esa de ls de ,dThread gksrhgh gSa fiNys lHkhPrograms esa Single Threaded Programs dks mi;ksx esa fy;k tkrk gSaAJava dh ,dProperty Multithreded dksSupport djrk gSaA ftlesa izksxzke dkMultiple Flow Control Use fy;ktkrk gSaA gj izksxzke dks fofHkUu NksVs&NksVsPrograms esa foHkkftr dj fn;k gSaA ftUgsaModules dgrs gSa rFkk izR;sdModule dh ,dThreads Consider fd;k tkrk gSaA og izksxzke tksMultiple Flow dksSupport djrk gSaA Multi

Threaded Program dgykrk gSaAog Hkk"kk tks Multi Treaded dksSupport djrk gSa mlsConcurrency dgrs gSaA vr% Java esa Threads, MainApplication Programs dkPart gksrh gSa rFkk tks Same Memory Space Share djrs gSA mUgsa Light WaitTreads ;kLight Wait Process dgk tkrk gSaA Threads dksParallel Run fd;k tkrk gSa ijUrqbldk vFkZ ;g ugha gSafd bUgsaSame Time ij ju fd;k tkrk gSaA D;ksafd lHkhThread Single Processers esa ju gksrs gSaA vr% Threads dkExecution Flow Shared gksrk gSaA Java dkInterpreter, threads ds chp esaSwitch Controlling dk dk;Z djrkgSaA ftllsThreads Concurrent Run gksrs gSaA Multi Threading Concept ds dkj.k ghJava dks nwljh Hkk"kk lsvyx ekuk x;k gSaA Multi Threading, User dks ,d le; esa cgqr ls dk;Z djus dh vuqefr nsrk gSaA Programs dksNksVs&NksVsThreads esaDivide dj fn;k tkrk gSaA rFkkProcessor }kjkParallel Execute fd;k tkrk gSaA Threadsdks eq[;r% Java Web Browser (Hot Java) ds fy, iz;ksx esa fy;k tkrk gSaA

Creating Threads

Java esaThreads Create djukSimple gSaA Threads dksObject dhForm esaImplement fd;k tkrk gSaA bldsfy, ,dMethod dks mi;ksx esa ysrs gSa ftls run() Method dgrs gSaA fdlh HkhThread ds fy, run MethodImportant gksrk gSa ftlesaThread BodyrFkkThread Behaviour dksImplemenmt fd;k tkrk gSaASyntax: - public void run ( )

{ //body of thred

}

Run Method dksThread dsObject }kjkInvoke fd;k tkrk gSaA Thread dksinitialize djus ds fy, ,d vU;Method (Start) dh vko;drk gksrh gSa fdlh Hkh u;sThread dks nks rjg lsCreate fd;k tk ldrk gSaA

(1)Thread Class dks Create djds%& fdlhClass dksThread Class ds }kjkExtend djRun Methoddks Over Write djukA

Syntax: - Class classname extends

(2)iwjhClass dks Thread esa Convert djuk%& blds fy, fdlhClass dksdefine djRunable Interfacels Implement djukA Runable Interface eas flQZ ,drunMethod gksrk gSaAExtending the Thread Class

tc Class dksRunable cukuk gSa ftlls vyx&vyxThread dks ju fd;k tk ldsaA blds fy, java.lang. ThreaddksExtend fd;k tkrk gSaA blls lHkhThread Method dksDirectly Access dj ldrs gSaA blds fy, fuEuStepsdksFollow fd;k tkrk gSaA

(1)Class Declare djuk lkFk ghThread dksclasslsExtend djukASyntax: - class classname extends Threads

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(2)Run Method dksimplement djuk tksCode ds Sequential Execution ds fy, Reposible gksrk gSaA(3)Thread Object dksCreate djuk rFkkThread Execution ds fy, Start Method dksCall djukA

(a) Declare The Classclass Thread1 extends Thread

{ // Class body

}

blds }kjk ,d u;kThread cuk;k x;k gSa tksThread1 gSaA

(b) Implement the run Method: - run Method dks Hkh Thread Class dk ,d Part ekuk x;k gSa tksImplement djus ds fy, Method dksOver ride djuk vko;d gSaA program esarun ( ) fuEu izdkj ls Implementfd;k tk ldrk gSaApublic void run ( )

{ // body of run

}

tc Run Method dks fdlhClass esaCall fd;k tkrk gSa rks mlClassls RelatedlHkhActions dksRun Methodesa Perform djrs gSaA(c) Starting new Thread:-u;kThread cukus ds fy, Thread Class dkObject cukuk vko;d gksrk gSaA

Thread1 ob1 = new Thread1( );

ob1.start ( );

mlCode esaFirst Line esaThread1 dksObj. ds }kjkinitialize fd;k x;k gSaA Thread dkObj.rks cuk fy;k x;k

gSa ijUrqThread Run ugha gks jgkA Thread dh blStage dksNew Born State dgk tkrk gSaAtc nwljhLine dks fy[kk tkrk gSa ftlesaObj. ds }kjkStart Method djsCall fd;k x;k gSaA rks ml le; ThreadNew Born Statels Runable State esa vk tkrk gSaArc Java dkRun Time Envoirnment Thread ds fy, Run Method dksinvoke djrk gSaA ftllsThread dks ,dubZState fey tkrh gSaA ftlls Runing State dgrs gSaAclass A extends Thread

{

public void run ( )

{

for (int i = 0; i

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t1. start ( );

t2.start ( );

}

}

bl izksxzke ds varxZr nksNew Thread dksInitialize djStart fd;k x;k gSaA ;sThreads yxkrkj ju djrs tk;saxsAThread dkExecution Sequential ugha gksrkA vr% Output Hkh Sequential ugha vk;sxkA tc ftlThread dksExecute gksus dkchance fey tkrk gSaA ml le; ogExecute gks tkrk gSaA vr% Threads ,d nwljs ijDepend

ugha djrs gSa vr% ,d ckj ;fnThread Start gks tkrs gSa rks mudkOrder of Exectuion Decide ugha fd;k tk ldrkAStoping & Blocking Threads

(1) Stopping the Thread: -tc fdlhRunning StateokysThread dksStop djuk gks rks mlds fy;sStopMethod dk iz;ksx fd;k tkrk gSaAmijksDrExample esa ;fn t1 Thread dks jksduk gks rks mlds fy, fuEuSyntax dkiz;ksx fd;k tk;sxkASyntax:-t1.stop ( );blStatement ds }kjkThread Runing Statelsdead State esa pyk tkrk gSaA tc dksbZThread viuhEnd Stateesa igqaprk gSa rks ogAutomatically Dead State esa pyk tkrk gSaA tc fdlhThread dksPremature Death esaigqapuk gks rks mlds fy, Stop Method dks mi;ksx esa fy;k tkrk gSaABlocking a Thread: - Thread dksTemporary Block fd;k tk ldrk gSa ftlls ogRunnable State esa ghjgsxkA blds fy, fuEuThread Method dks mi;ksx esa fy;k tkrk gSaA

(1) sleep ( ):-blMethod dks ;fn fdlhThreadlsSpecific Time ds fy, Blockdjuk gks rc mi;ksx esafy;k tkrk gSaA

(2) suspend ():- Suspend dksThread Order Blockdjus ds fy, mi;ksx esa fy;k tkrk gSaA(3)wait ( ):- Thread dks fdlhSpecific Condition ds fy, Blockdjuk gks rksWait Method Use esa fy;k

tkrk gSaAbu lHkhMethods ds }kjkThread ykuk vkSj mlThread dkssleep( ) ds }kjkBlockfd;k x;k gks rks og dqN le;ipkr~ ;kSpecific Time esa iqu% Runable State esa pyk tkrk gSaA supend( ) ds }kjk tc Thread dksBlockdjfn;k tkrk gSaA vkSj iz;ksx fd;k tkrk gSaA rFkkwait( ) ds fy, notify dks iz;ksx esa fy;k tkrk gSaA

Life Cycle of Threads

Thread viuhLife Time esa fofHkUuStagesls gksdj xqtjrk gSa%&(1)new born state(2) runable state(3) running state(4)blocked state(5)dead state

Diagram

(1) New Born State:-tc thread dk Obj. Create fd;k tkrk gSa rc Thread dk tUe gksrk gSa ftls newNewborn State dgk tkrk gSa bl State esa Thread dks ju ugha fd;k tkrkA bl State esa Thread ij nksOperations dksPerform fd;k tkrk gSaA

New born stateNew State

Runable Runnin Dead

Blockedsleep

suspend wait

Idle State

StopActive

State

Stop

stop

resume notify

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(a) Start Method (b) Stop Method

eq[;r% Newborn State ds cknThread dhNext State, Runable gksrh gSa ;fn fdlh nwljsMethod dks Applyfd;k tkrk gSa rksThread Execption Throw dj nsrk gSaA

(2) Runable State:- Runable State esaThread Execution ds fy, rS;kj gksrk gS vkSjProcessor dhAvalability dkWait djrs gSa ;g dg ldrs gSa fdThrow queue esa bdV~Bk gks tkrk gSa vkSjExecution ds fy,Wait djrk gSa ;fn lHkhThread dksSame Priority nh xbZ gSa rks muThreads dksExecution ds fy, differenttimes slot esadivide dj fn;k tkrk gS tksRound Robin Fashion esa gksrh gSa ogProcess ftlesaThreads dksTime Slot esadivide fd;k tkrk gSaA mls Time Slice dgrs gSaAYeild ( ) ds }kjkthread dhPriority dksControl fd;k tkrk gSaA

(3) Running State:- Running Statels rkRi;ZThread dsExecutionls gSaA ,dThreadrc rd ugh :drk gStc rd dksbZHigh Prority dkThread uk vk tk,A dksbZ HkhRunning Thread fuEuSituation esa :d tkrk gSaA

(a) tc mlThread dksSuspend dj fn;k x;k gksA Suspendls iqu% Running State esa ykus ds fy, resume ( )dks mi;ksx esa ysrs gSa ftlls ogRunable State esa vk tkrk gSaA

(b.) tc Thread dksSleep ( ) }kjk dqN nsj ds fy, bbkdj fn;k tk,A ;gk Time Mili Second esa gksrk vr%Thread Specific Time ds cknQueuels ckgj vk tk, vkSjRunable State esa pyk tkrk gSaA

New Born

Runable Dead

Start Stop

Runable ... .

Yeild

RUNNING RUNABLE SUSPEND

RESUME ( )

Suspend ( )

RUNNING RUNABLE SLEEP

Sleep ( )

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(c.) tc Thread dksWait djokuk gks rksWait ( ) Use fd;k tkrk gSaA Waitls iqu% Runable State esa ykus ds fy,Notify ( ) dks mi;ksx esa ysrs gSaA

(d) Blocked State:-tc fdlhThread dksRunable State esa tkus ls jksduk gks rksBlocked State dks mi;ksx esafy;k tkrk gSaA Thread dks Suspend, Sleepo Wait }kjk block State esa Mkyk tkrk gSaA blState dks NotRunable Hkh dgrs gSaA vxj fdlhMethod dksSuspend dj fn;k tkrk gSa vkSj mls okilRunable State esa ykus dsfy, Resume ( ) dks mi;ksx esa ysaxs(e) Dead State: -gjThread dh viuhLife Cycle gksrh gSa tksRun ( ) ds }kjk lHkhExecution dksCompletedj fy;k tkrk gSa rksThread Dead gks tkrk gSaA blsThread dhNatural Death Hkh dgrs gSa ;fn fdlhThread dksRunning State esa ghKill djuk gks rksStop ( ) dks mi;ksx esa fy;k tkrk gSa blsThread dhPremature Death dgktkrk gSaA

Using Threads Methods

Thread Class esaThread Behaviour Controlling ( ) dks mi;ksx esa fy;k tkrk gSaA Thread dks ,dStateslsnwljhState esa ys tkus ds fy, gh vyx&2 Method dks mi;ksx esa fy;k tkrk gSaA tSlsYeild, SleeprFkkStopMethod, yield methodls fdlh HkhRunning Thread dksBlockfd;k tk ldrk gSaA lkFk ghThread Priority dkscny fn;k tkrk gSaA

Thread Exception

Sleep Methodls tc Hkh fdlhThread dksRunnable State esa yk;k tkrk gSa rks mlls RelatedlHkhStatementdksTry vkSjCatch Blockesa fy[kk tkrk gSaA D;ksafdSleep ( ) ds }kjkExeception dksThrow fd;k tkrk gSaA ;fnizksxzkeException dksCatch djus esaFail gks tkrk gSa rks izksxzke dkCompilation gh :d tkrk gSaA Java, RunSystem }kjk illegalThreadStateException dksThrow fd;k tkrk gSaA tc dksbZMethod Thread dsGivenStatement dksInvoke ugha dj ikrkAFor Example:-tc Thread Sleeping Statements esa gksrk gSa rc ogResume dksInstruction dksHandle ughadj ikrkA Catch Statement ds }kjk lHkhExecption dksHandle fd;k tkrk gSaA

(1) Catch (ThreadDeath e);{ // body of catch;

// killed Thread;

}

(2) catch (InterruptedException ( ))

{

// body of catch;

// cant handled in the current state;

}

(3) catch (IllegalArgumentException e)

{ // body of catch;

// illgal method argument;

}

(4) catch (Exception e)

{ // body of catch;

// Any other exception;

}

RUNNING RUNABLE WAIT

Wait ( )

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Thread Priority

gjThread dksPrority Assign dh tkrh gSa ftllsThread Exception dkScheduler; fd;k tkrk gSaA ge tkursgSa fdThread dkssame Priority nh tkrh gSaA lHkhSame PriorityokysJava Schedule }kjkEqual Treatmentfn;k tkrk gSaAsetPriority( ) ds }kjkThread Priority dksSet fd;k tkrk gSaASyntax:- Thread name.setPriority (int num);

int num ,dInteger Value gSaA ftllsThread Priority dksSet fd;k tkrk gSaA Thread Class fofHkUuPriority

Constant dksdefine djrh gSaA(1) MIN_PRIORITY = 1;(2) NORM_PRIORITY = 6;

(3) MAX_PRIORITY = 10;

bl izdkj buConstant Value dksUse esa ysdjPriority Set dh tkrh gSaA By Default Thread dhNormalPriority Set gksrh gSaA User Level Process esas NORM Priotity dks mi;ksx esa fy;k tkrk gSaA ijUrqBack GroundTasktSls%& Network I/O, Screen Pointing etc. ds fy, eq[;r% Minimum Priority dks mi;ksx esa fy;k tkrk gSaAtc High Priority Value dks mi;ksx esa ysuk gSa rks blds fy, vR;Ur j[kj[kko dh vko;drk gksrh gSaA

Synchronization

ge tkurs gSa fdThread ds lHkhDate vkSjMethod run( ) esadefine fd;k tkrk gSaA ;fn ;g lkspk tk, fdMethod

Outside define fd;k tk, rks bllsSerious Problem Create gks tkrh gSaAFor Example: -;fn ,dThread fdlhSpecific File dsRecord dhReading dj jgk gSa vkSj mlh le; dksbZ

vU; ThreadmlFile esaWrite djuk pkgrk gSa rks blsSerious Problem Occur gks ldrh gSaA blProblems dks

Resolve djus ds fy, ,dTechnique dks mi;ksx esa fy;k tkrk gSaA ftllsSynchronization dgrs gSaA

Synchronization ds }kjk fdlh Hkh leL;k dks Solve fd;k tk ldrk gSaA tc fdlhFile esaUpdation djuk gks rks

igysFile dksSynchronize fd;k tkrk gSaA blds fy, fuEuMethod dks mi;ksx esa fy;k tkrk gSaA

Synchronizaton void Update (// Code for Syncrinize) tc fdlhMethod dksSynchronize Declare fd;k

tk ldrk gSaA rksJava ,dMonitor Create djrk gSa vkSj mlsMethod ds First Time Callls ysdj lHkhCalls dks

Check djrk gSaA tc rd ml Monitorml Thread dks hold fd, gq, j[krk gSa rc rd dksbZ nwljk Thread

Synchronize Section esaEnter ugha gks ldrk gSaA Monitor ,d pkch dh rjg gSa ftls flQZ Threads ds }kjk gh

Open fd;k tkrk gSaA tc Thread Synchronize Method ds }kjk viuk dk;ZComplete dj ysrk gSa rc Monitor

ds }kjkNext Thread dks mi;ksx esa fy;k tkrk gSaA tksSame Response dks mi;ksx esa ysus ds fy, rS;kj jgrk gSaA

Synchronize Blockdks fuEu izdkj iznfkZr fd;k tkrk gSaA

Syncronize (block object)

{

}Interesting Conditionrc mRiUu gksrh gSa tc nks ;k nks ls vf/kdThreads ,d ghResource dksControl djus ds

fy, Wait djrh gSa bl le; dead lockdh fLFkfr mRiUu gks tkrh gSaA blds fy, fuEuThreads gSa%&

Threads A

synchronize method 2 ( )

{


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{

;

}

} Thread B


{


}}

}

Implementing The Running Interface

ge tkurs gSa fdThreads dks nks izdkj lsCreate fd;k tkrk gSaA(1)Using Thread Class(2) Implementing Runable Interface

Runable Interface run( ) dksDeclare djrk gSa ftllsprograms esa Thread dksImplement fd;k tkrk gSa bldsfy, fuEuSteps dksFollow fd;k tkrk gSaA

(1)Class dks Declare djuk rFkk mls runable interface ls implement djukA Class ImplementRunable

(2)Run ( ) dksImplement djukA Public void num ( )(3)Object define djThread dksCreate djukA(4)Start ( ) ds }kjkThread dksCall djuk vkSj mls ju djukA A. Start ( );

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UNIT - VApplets

Applet Small Java Programs gS ftUgsa Internet Computing ds fy, mi;ksx esa fy;k tkrk gSaA bu SmallPrograms dksInternet ij ,dComputerls nwljsComputer ijApplet Viewer ;kWeb Browser }kjk jufd;k tkrk gSaA fdlh HkhApplication Program dh rjgApplets esa Hkh cgqr lhModifications fd;s tk ldrs gSaAApplets, Airthmetic Operation, Graphics, Sounds, User input, moving image create animationsrFkkInter active games dks HkhIntract ;kDevelop fd;k tk ldrk gSaA Java ds }kjkFully Interactive Multimedia

dks mi;ksx rFkkCreate fd;k tk ldrk gSaA(1)Local Applet(2)Remote Applet

Local & Remote Applets

Web Pages ijApplets dks nks izdkj ls ns[kk tk ldrk gSaA(1)User ds }kjk Lo;a ds Applets Develop fd;s tk ldrs gSa vkSj mUgsaWeb Page ij ns[kk tkrk gSaA(2)tc fdlhRemote Computer SystemlsApplets dksDownload fd;k tkrk gSaA rks buApplets dks Hkh

Web Browser esa ns[kk tkrk gSaA(3)tc Applet dksLocally develop fd;k tkrk gSa rks ogApplet dksLocal System esa gh jjorh gSa ftls

Local Applet dgrs gSA tc fdlhWeb Page }kjkLocal Applet dksFind fd;k tkrk gSa rks blds fy,Internet Connection dh vko;drk ugha gksrh gSaA blApplets dks Local System dh Directory esaSearch fd;k tkrk gSaA

Remote Applet dks fdlh vU; User }kjk cuk;k tkrk gS vkSj buApplet dks LVksj HkhRemote Computer ij fd;ktkrk gSaA vr% bu Applets ds fy, Internet Connection dh vko;drk gksrh gSA ;fn System esa InternetConnection gS rksRemote Applet dks User dsSystem ijDownload dj ju fd;k tk ldrk gSA RemoteApplet dksLoad djus ds fy, Web ijApplet Address dk gksuk vko;d gSA buAddress dksURL dgk tkrkgSA

Difference Between Applets & Application

AppletsrFkkApplication Program nksuks ghJava Programming ds varxZr vkrs gS ijUrqbuesa dqN DifferencegSaA Applets dksFull Featured Application Program ugha dgk tkrk D;ksafd bUgsa NksVs&2 dk;ksZ dksComplete djusds fy, cuk;k tkrk gSa bUgsa Internet ij mi;ksx djus ds fy, Design fd;k tkrk gSAAppletsrFkkApplication Program esa vUrj fuEu gS%&

(1)Applets ds }kjkProgram Execution ds fy, Main Method dks mi;ksx esa ugha fy;k tkrk gSaA Appletsdks tc yksM fd;k tkrk gSa rksApplet Class dsMethod ghApplet dksStartoExecute djrs gSaA

(2)Application Programs dh rjgApplets dks independently run ugha fd;k tk ldrk gSaA buds fy,Web Page dks mi;ksx esa fy;k tkrk gSaA

(3)Applets dksLocal Computer dhFiles ij lsRead vkSjWrite ugha fd;k tk ldrkA(4)NetworkijApplets vU; ServerlsCommunication ugha djrh gSA(5)Local Computer dsPrograms dksApplet Run ugha dj ldrhA(6)Applets dks vU; Programming Liabrary tSlsC, C++ etc. dks mi;ksx esa ysus dk vf/kdkj ugha gSaA

bu lHkhLimitations dksSystem Security ds fy, rS;kj fd;k x;k gSA blds }kjk ;g Li"V gS fdApplets, LocalSystem dks dksbZ uqdlku ugha igqpkrh gSA

Preparing To Write Applets

Java, Application Program dks Single Main Method vkSj Object Create dj Execute fd;k tkrk gSaAApplets dksCreate djus ds fy, fuEu ckrksa dks /;ku esa j[kuk vko;d gSa: -

(1)Applets dks dc mi;ksx esa fy;k tk;sxkA(2)Applets dSls dk;Z djrk gSA(3)Applets dks dkSu&2 lsFeatures gSaA(4)tc Lo;a dhApplets dksCreate fd;k tkrk gS rks mUgsaStart djus ds fy, blMethod dk iz;ksx fd;k

tk;sxkA

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Needs for Applets

(1)tc User, Web Page dksDynamic Lookfn;k tkrk gSa rc Applets dk iz;ksx fd;k tkrk gSaAtSls%& 'ks;j ekdsZV ds fy, fdlhWeb Page dksDesign fd;k x;k gS vkSj mudhList dksBar Chats esaShowfd;k tkrk gSA

(2)tc Web Page ijFlesh Output dh t:jr gksrh gSa rc Applets dh vko;drk gksrh

imp java

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