meljun cortes manual java programming csci03

7/27/2019 MELJUN CORTES MANUAL JAVA Programming CSCI03

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CSCI03: Computer Programming (Java Application)

PREPARED BY: MELJUN P C!"#ES

P"ELIM PE"I!$

C%apter &: Java !vervie'

Java is high-level, object-oriented programming language, similar to !! but

simpli"ied to eliminate "eatures that cause programming errors# $he Java source code"iles %"iles &' #java e(tensions) are compiled into a "ormat called b*te code %"iles &' #class

e(tensions), &'c can then be e(ecuted b* a Java +nterpreter#

A rie *i+tor, o Java:

Java language, originall* called the A, &as developed b* ./0+R1Y$E02s Engr# James 3osling# $he language &as intended "or use in un2s

project research to &or4 on programming so"t&are to control consumer electronic device#

+nitiall*, the !! language &as used as the brains "or the smart appliances %such

as interactive $52s, omniscient ovens, hand-held devices, sel"-top bo(es, and the li4e)#3osling &as unhapp* &ith the results he &as getting b* &riting programs &ith !!, andso he &as "orced to developed his o&n language that suit his needs# $he language he

created &as small in si6e %so it could run on limited memor*), e""icient, reliable, and ver*

portable so it could run in an* devices#

Java language &as o""iciall* launched in 7889# +t &as modi"ied to ta4e advantage

o" the orld ide eb# $he eb Runner %later named as ;ot Java) &as the ver* 7st&eb

bro&ser created in Java# +n 7889, the /etscape /avigator +nternet Bro&ser &as alsodeveloped to support Java#

-eature+ o Java:

7) imple, 1bject-oriented, and


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Note: Java applications and applets are ver* portable that the* run in an* t*pe o"

operating s*stems such as D1, indo&s, olaris, 0aos, ./+?, @inu(, etc#

) Architecture /eutral and Portable

Java technolog* is designed to support applications that &ill be deplo*ed into

heterogeneous net&or4 environments#

$o accommodate the diversit* o" operating environments, the Java computerproduct generates b*te codes an architecture neutral intermediate "ormatdesigned to transport code e""icientl* to multiple hard&are and so"t&are

plat"orms# $he interpreted nature o" Java technolog* solves both the binar*

distribution problem and the version problem, the same Java programminglanguage b*te codes &ill run on an* plat"orm#

C) ;igh Per"ormance

$he automatic garbage collector runs as lo&-priorit* bac4ground thread,

ensuring a high probabilit* that memor* is available &hen reuired, leading to

better per"ormance#

Java Program ;ello

orld10P+@ER

+ / $ E R P R E $ E R

;E@@1

1R@D

;E@@1

1R@D

;E@@1

1R@D


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9) +nterpreted, $hreaded and D*namic

$he Java interpreter can e(ecute Java b*te codes directl* on an* machine to

&hich the interpreter and run-time s*stem have been ported#

Java technolog* is multithreading capabilit* provides the means to build

applications &ith man* concurrent threads o" activit* 0ultithreading ma*

results in a high degree o" interactivit* "or the end user#

hile the Java compiler is strict in its compile-time static chec4ing, the

language and run-time s*stem are d*namic in their lin4ing stages#

-rom +ource to e.ecuta/le: #%e Java Programming Proce++

Note: $he Java source code %#java "ile) is normall* compiled to produce the b*tecodes

"ile %#class "ile) that is normall* interpreted b* the Java 5irtual 0achine#

m*Program#Java

10P+@ER

+ / $ E R P R E $ E R

m*Program#class 0* Program


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Page C

JAA 1E2!"$S

$he "ollo&ing are reserved b* the Java @anguage and cannot be used asidenti"iers:

abstract continue i" protected transientBoolean de"ault implements public tr*

Brea4 do import return void

B*te double instance o" short volatilease else int static &hile

&itch e(tends inter"ace super

atch "inal long s*nchroni6ed

har "inall* ne& thislass "loat pac4age thro&

onst "or private thro&s

JAA $A#A #2PES

+#) Primitive4built in data t*pes#

5 Categorie+

/umeric4 integral and "loating point t*pes#

Boolean - true ' "alse

JAA IN#E6"AL #2PES:

7# b*te represents on integer e(actl* 7 b*te o" storage#

=# short - represents on integer e(actl* = b*te o" storage#

# int - represents on integer e(actl* C b*te o" storage#C# long - represents on integer e(actl* b*te o" storage#

9# char represents .nicode charactersF reuires e(actl* = b*tes o" storage#

JAA -L!A#IN6 #2PES:

7# "loat represents a "loating point number reuiring e(actl* C b*tes o" storage#


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CSCI03: Computer Programming ( Java Application )

Page 9

$*pe Description ommon 0ethods

Boolean +t is a class containing a Boolean "ield used "or - boolean value % ),

&rapping a value o" the primitive t*pe Boolean getboolean % ),in an object# 5alueo" % )

haracter +t is a class containing a char "ield used "or - char5alue % ),&rapping a value o" the primitive t*pe char compareto % ),

in an object# 3ett*pe % ),isDigit% ),

is@etter % ),

to.ppercase % ),to@o&ercase % )

Double +t is a class containing a double "ield used "or - double5alue % ),&rapping a value o" the primitive t*pe double totring%), valueo"%),

in an object# parseDouble % ),


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Page I

$*pe Description ommon 0ethods

1bject +t is the root o" the class hierarch*# Ever* - done%), euals%),lass has object as a superclass %or parent "inali6e%),nashcode%)

lass)F and there"ore, all objects, including noti"* % ), tostring % )

Arra*s, implement the methods o" the class#

"APPE" CLASS &rapping primitive value to an object#

1bject contains method "or manipulating a data such as converting a value toanother t*pe o" value#

E(# string to int

int to string%see sample program no# =)

lass 0ethod 1utput

+nteger parse+nt %) +nt@ong parse@ong %) long


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Page O

Sample Program No5 ''bu""eredreader command "or input

import java#io#Fpublic class ;ello Java

public static void main %Arra* K L args) thro&s E(ception

Bu""eredReader br Q ne& Bu""eredReader %ne& +nputtreamReader%s*stem#in) )Fstring "irstname Q G GF

string lastname Q G GFs*stem#out#println %GPlease t*pe *our "irst name:H)F"irstname Q br#readline%)F

s*stem#out#println %GPlease t*pe *our last name:H)F

lastname Q br#readline%)Fs*stem#out#println %G;elloH ! "irstname ! G G ! lastname)F

s*stem#out#println %Gelcome to Java ProgrammingMH)F

N

N

Sample program No3 ''&rapping class program "or int

import java#io#

public class um+t.o

public static void main %tring args K L) thro&s E(ception Bu""eredReader br Q ne& Bu""eredReader %ne& +nputtreamReader%s*stem#in) )F

int num7Q>F

int num=Q>F

int sumQ>Fs*stem#out#println %GEnter 7stno:H)F

num7Q+nteger#parse+nt%br#readline%))F

s*stem#out#println %GEnter =ndno#:H)Fnum7Q+nteger#parse+nt%br#readline%))F

sumQnum7!num=F

s*stem#out#println %G$he sum is:H ! sum )FN

N


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Page

JAA !PE"A#!"S special s*mbols used "or mathematical "unctions, some t*pes o"

assign and logical statements# Java supports several operators that are "airl* derived "rom

and !!# ;o&ever, most Java operators behave di""erentl* "rom the counterparts in

other languages#

P"ECE$ENCE 7 *IE"A"C*2 !- !PE"A#!"S

8 9 ( ) - ( )- used to group e(pressions

8- used to access methods and variables &'in object and

classes# 9 used "or arra*s#

;; 7 ?;

C!MP!NEN#S 4 these are buttons, labels, te(t "ields, lists, menus, etc## that lie

at the center o" the 3.+, b* using either a mouse or 4e*board, the user can

interact &ith these components to accomplish use"ul tas4s#

C!N#AINE"S 4 such as panels, "rames, and dialogs organi6e components into

groups#

LA2!U# MANA6E"S 4 automaticall* la*out the components o" the 3.+ &ith

in the containers# %"urther e(planation at the bac4U)

EEN#S 4objects that are "ired &hen the user-interact &ith the 3.+s

components and containers# %see "urther e(planation)

-"AMES 4is the component &e use "or the &indo&s %see e(ample)

LA2!U# MANA6E"S are special objects that determine the si6e and position o" the

object in the container# Java components are arranged in containers b* de"ining the t*peo" la*out manager object that determines the placing o" these components#

$he "ollo&ing are the commonl* used la*out managers in JavaF

-lo' La,out 4 le"t-to-right, top-to-bottom component arrangement that maintains

the components dimension# orFer La,out 4 manages container area into 9 regions: north, south, east, &est

and center#

6riF La,out 4uses grid o" ro&s and columns, "ills each grid &ith component#

CarF La,out 4uses panel li4e a dec4 o" cards#


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6riF ag La,out 4uses grid o" ro&s and columns, components are placed across

several grid areas#


Page 77

-ig &G #%e A# proviFe+ cla++e+ in creating 6UI component+ anF container+

1BJE$


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-ig &H #%e -lo' La,out manager %onor+ t%e component+ Fimen+ion #%e

component+ +ie i+ not altereF '%en t%e container i+ re+ie+


Page 7=

-ig & #%e orFer La,out maintain+ t%e location o t%e component+ #%e

component+ +ie i+ altereF '%en t%e container i+ re+ieF

V

V

Border @a*out

/orth

East

:est

outh

enter

V

V

Border @a*out

/orth

East

:est

outh

enter

A"ter indo& is resi6ed


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Page 7

-ig &K #%e 6riF La,out manager arrange+ component+ in a ta/le


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Event+ 4 something that occurs &'in an object that an application or other object

might &ant to 4no& about to &'c it might possible react# $his is represented as a

Java class included in the java#a&t#event pac4age#

Event Li+tener 4the inter"ace responsible "or implementing event response

methods that are called in response to the speci"ic t*pe o" events#


Page 7C

-ig %e A# Event+ *ierarc%,


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$he java#a&t#event pac4age provides inter"aces and classes "or dealing &ith

di""erent t*pes o" events b* A$ components#


Page 79

Java Event Cla++e+ are $iviFeF into 5 6roup+:

1bject

Event 1bject

A$ Event

$e(t

Even

+tem

Event

+nvocation

Event+nput

0ethodEvent

;ierarch*

Event

omponent

Event

Adjustment

EventAction

event

indo&Event

PaintEvent

+nputEvent


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7# emantic Event events that are "ined in response to the high-level graphical

user inter"ace interaction &'in the conte(t o" a certain component#=# @o&-level Events events that are "ined in response to the lo&-level input or

graphical user inter"ace interaction such as 4e*-press or "ocus-change#

JAA$!C

+# ingle @ine omment ' bo* te(t '++# 0ultiple @ine omment '

bod* te(t

bod* te(t

bod* te(t '

++# ommon Javadoc $ags

*nta( W name o" the tag S/ote: Each tag has a purpose to describe a particular attribute o" the entit* being

commented#

#%e ollo'ing are commonl, u+eF JavaFoc #ag+:

7# W author programmer2s nameF used "or classes X inter"aces#=# W version version o" the programF used "or classes X inter"aces

# W param description o" a "ormal parameterF used "or methods X constructors#

C# W return description o" a return valueF used "or methods#

9# W e(ception %or W thro&s) description o" an e(ceptionF used "or methods Xconstructors#

I# W see re"erence to a related entit*F used "or classes X inter"aces, constructors,

methods, X data "ields#

Sample Program U+ing JavaFoc #ag+:

'

pS

javadoc comments# Javadoc comments "or classes can be bro4en into t&o parts:

a description part X a tags part# $his is the description part# $he parts should be separated b* one empt* comment line# 'pS, 'pS also, there should be no lines


Page 7I

bet&een the end o" the Javadoc comment and the beginning o" the entit* it


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describes# 'pS

Wauthor @il* ;ou

Wauthor ean Bu"ano

Wversion 7#>

'public class $&o+nts

int "irstFint secondF

'

+nitiali6es codeS "irst 'codeS and

codeS second 'codeS to codeS o 'codeS'

public $&o+nts %)

"irstQsecondQ>FN

' +nitiali6es codeS "irst 'codeS and codeS second 'codeS to arguments

Wparam ( value to &'c codeS "irst 'codeS is initiali6ed Wparam * value to &'c codeS second 'codeS is initiali6ed

'

public $&o+nts %int (, int *)

"irstQ(FsecondQ*F

N


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'

omputes the sum o" the t&o integers

W return the sum o" the t&o integers

'

public int sum %) return "irst ! secondF

N'

+ncrements codeS "irst 'codeS b* the argument

W param ( the value b* &hich codeS "irst 'codeS &ill be incremented'

public void add$o


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a# partial i" statement

s*nta(: i" %e(pression)

statement%s)FN

b# "ull-i" statements*nta(: i" %e(pression)

statement%s)F

Nelse

statement%s)FN

c# /ested i"U else i" statement*nta(: i" %e(pression7)

statement%s)F

Nelse i" %e(pression=)

statement%s)F

N#

#

else

statement%s)F

N



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Page 78

E(ample:

7#) i" %(S7>>)s*stem#out#println %G $he number is greater than 7>>H )F

else

s*stem#out#println %G $he number is greater than 7>>H )F

=#) import java#io#Fclass i"Elsetatement

public static void main %string K L args) thro&s e(ception

Bu""eredReader brQne& Bu""eredReader %ne& +nputtreamReader%s*stem#in) )F

+nt a,bF

*stem#out#println%GPlease enter "irst integer:H)F

AQ+nteger#parse+nt%br#readline%))F*stem#out#println%GPlease enter second integer:H)F

*stem#out#println%GaQH! a)F

*stem#out#println%GbQH! b)F+" %aSb)

*stem#out#println%Ga is greater than bH)F

Else*stem#out#println%Ga is less than bH)F

N

N#) import java#io#F

class i"Elseample public static void main%string K L args) thro&s e(ception

Bu""eredReader brQne& Bu""eredreader%ne&+nputtreamReader%s*stem#in))F

+nt ageF

*stem#out#print%GEnter *our age:H)FBageQ+nteger#parse+nt%br#redline %))F

+" %age SQ7)

*stem#out#println%GYou2re allo&ed to voteMH)FElse

*stem#out#println%Gtoo *oung to voteMH)F

NN


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Page =>

C#) import java#io#F

class Pass&ord public static void main %string K L args) thro&s E(ception B.""eredReader brQne& Bu""eredReader %ne& +nputtreamReader

%s*stem#in))F

tring input Q G GFtring pass Q GpangetHF

*stem#out#print%GEnter a pass&ord:H)F

+nputQbr#readline %)F+" %pass#euals%input))

*stem#out#println%GAccess 3ranterH)F

Else

*stem#out#println%GAccess DeniedH)FN

N

9#) import java#io#F

class 3radeRange

public static void main%string args KL) thro&s E(ception Bu""eredReader brQne& Bu""eredReader%ne&

+nputtreamReader%s*stem#in))F

+nt gradeF*stem#out#print%GEnter desired 3rade:H)F

3radeQ+nteger#parse+nt%br#readline%))F+" %grade Q7>> Xgrade SQ8>)

*stem#out#println%G1utstandingH)FElse i" %grade Q8 X grade SQ>)

*tem#out#println%Gatis"actor*H)F

Else i" %grade QO8 X grade SQO9)*tem#out#println%G/eeds +mprovementH)F

Else i" %grade QOC X grade SQ9>)

*tem#out#println%G


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Page =7

#%e S'itc%O ca+e con+truct

$his decision construct is used "or ma4ing a choice among multiple e(ecution

paths, X the choice can be upon an int value# $his statement successivel* tests the value

o" an e(pression on value against a list o" integer or character constants# hen amatch is"ound, the statements-associated &' the case are e(ecuted#

*nta(:&itch %variable/ame) S char, b*te, short, int onl*

case const7: statement%s)F brea4F

case const=: statement%s)F brea4Fcase const: statement%s)F brea4F

U

case constn: statement%s)F brea4Fde"ault: statement%s)F

N

$he brea4 statement causes the program "lo& to e(it "rom the bod* o" the s&itch

construct#

$he de"ault 4e*&ord is comparable to the else part o" the i" statement# $he statements

associated &' this 4e*&ord are e(ecuted i" the value o" the s&itch variable does notmatch an* o" the case constants#

E(amples:

7#) import java#io#Fclass s&itchtatement

public static void main%string args KL) thro&s E(ception

Bu""eredReader brQne& Bu""eredReader%ne&+nputtreamReader%s*stem#in))F

int nF

s*stem#out#println%GPlease enter an integer:H)FnQinteger#parse+nt%br#readline%))Fs&itch %n)


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Page ==

ase 7: s*stem#out#println%G1neH)F brea4F

ase =: s*stem#out#println%G$&oH)F brea4F

ase : s*stem#out#println%G$hreeH)F brea4Fase C: s*stem#out#println%G


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Page =

#) import java#io#Fclass &itchhar

public static void main%string args K L) thro&s E(ception

Bu""eredReader brQne& Bu""eredReader%ne&

+nputtreamReader%s*stem#in))Ftring m* charF

*stem#out#println%GEnter a letter:H)F

0*harQcharSbr#readline&itch%m*char)

ase ZA2 : s*stem#out#println%GAdorableH)Fbrea4Fase ZB2 : s*stem#out#println%GBeauti"ulH)Fbrea4F

ase Z2 : s*stem#out#println%GharmingH)Fbrea4F

ase Z.2 : s*stem#out#println%G.gl*H)Fbrea4F

De"ault : s*stem#out#println%G/o ommentH)FN

N

N

#%e %ile Loop

$his construct e(ecutes a given statement or bloc4 o" statements again X again as

long as the value o" the e(pression is true# $he e(pression must be a Boolean e(pression

X must return the variable called the loop control variable#

*nta(: &hile %e(pression)

statement%s)FN

#%e Fo '%ile loop

+n the doU &hile loop, the e(pression %or condition) is evaluated at the end o" the

loop to ensure that the statements are e(ecuted at least once# imilar to the &hile loop, thestatements are e(ecuted repeatedl* as long as the e(pression is true#


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Page =C

*nta(: do

statement%s)F

N&hile %e(pression)F

#%e or loop

$his loop construct e(ecutes a given statement or bloc4 o" statements "or a

de"inite number o" times# +t per"orms a set o" instructions or bloc4 o" statementsrepeatedl* until a certain condition is reached#

*nta(:


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Page =9

=#) import java#io#F

public class "actorial public static void main %string KL args) thro&s E(ception

Bu""eredReader brQne& Bu""eredReader%ne& +nputtreamReader%s*stem#in))F

F a!!) +nt ", (, ansF

*stem#out#println%GEnter a number:H)F


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Page =I

C#) import java#io# public class gcd

public static void main %string KL args) thro&s E(ception

Bu""eredReader brQne& Bu""eredReader%ne& +nputtreamReader%s*stem#in))F +nt num7,num=,tempF

*stem#out#println%GPlease t*pe t&o positive numbers:H)F

/um7Qinteger#parse+nt%br#readline%))F

/um=Qinteger#parse+nt%br#readline%))Fhile %num=MQ>)

num7Qnum=F num=QtempF

N

*stem#out#println%G$heir 3reatest ommon Divisor is:H ! num7)FN

9#) import java#io#F public class Reverse

public static void main %string KL args) thro&s E(ception

Bu""eredReader brQne& Bu""eredReader%ne& +nputtreamReader%s*stem#in))F

+nt num, rightdigitF *stem#out#println%GEnter a number:H)F

/umQ+nteger#parse+nt%br#readline%))F

Do

rightdigitQnum [ 7>F

*stem#out#println%rightdigit)F/umQnum'7>F

N

&hile %numMQ>)F


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N

N


Page =O

MI$#E"M PE"I!$

C%apter 5: Cla++e+ !/ect+

lass re"ers to a group or set o" objects having the same states and behavior# +t can alsobe de"ined as the categor* o" objects that de"ine all the common properties o" objects

belonging to it#

+n 11P, a class is the derived t*pe that represents a collection o" related data X

collection o" methods %"unctions) that operate on the class data#

1bject de"ines sel"-contained entities that consist o" an identit*, state X behavior

%procedures) to manipulate data# An object is a representation o" something#1bject2s re"erences are variables, &hich are o" a class t*pe that identi"ies the

location in the memor*#

-ig 50

/ote: A class usuall* represents the GblueprintH o" all objects belonging to it#

!JEC# "ELA#I!NS*IPS:

DA$A

Attributes %or states)

0E$;1D

Behaviors %or "unctions X procedures)

@ A / A 0 E


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7#) Association e(ist &hen an object contains a re"erence to another object# $his is

usuall* re"er to as Ghas aH relationship#


Page =

-ig 5&

Ever* tudent has a $eacher

ample +llustration /o# =

3ender

AgeEmplo*ee ode

Years o" ervice

ubjects

3ender

Age3rade


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-ig 55

UniieF MoFeling Language (UML)

.0@ is a general-purpose notational language used "or speci"*ing X visuali6ing

comple( so"t&are, usuall* large object-oriented project# .0@ uses several t*pes o"

diagrams such as case diagram, class diagram X the state chart diagrams#


Page =8

-ig 53

toc4 /o#$itle

Rating

5ideo +tem

+D

/ame5ideo Rented

5ideo tore

ostumer


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$he ase Diagram is used to describe ho& the users are using the objects in thes*stem#


Page >

-ig 5Q

Account

3et Balance

Deposit

ithdra&

Balance


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$he tate chart Diagram is used to describe the li"ec*cle or stages o" objects inthe s*stem#


Page 7

1rder;eld

1rder

Bac4-order

1rderdiscarded

1rderlosed

1rder

Delivered

1rder+tem

Placed

1rder

reate

d


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-ig 5G

$he lass Diagram is used to describe the attributes X behaviors o" objects in the

s*stem#

UML S2M!LS:

Cla++ S,m/ol:

Acce++ Speciier S,m/ol+:

! public Q an*&here- private Q &'in the class it is declared

\ protected Q similar to private but the attribute &ill be available to sub-class#

G G de"ault Q similar to public but &'in its pac4age#


/A0E

A$$R+B.$E

1PERA$+1/ 1R

0E$;1D

5ideo Rented

$itleRent Dateharge

Due date

5ideo Rented

3entRent Date

etDue Date

lass /ame

- Attributes

- Attributes

- Attributes

! 0ethods! 0ethods

! 0ethods

Ban4 Account

Balance

Account no#tatus

! Deposit % )

! ithdra& % ) ! +nuire Balance % )


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Page =

$E-ININ6 $ESI6NIN6 CLASSES:

Java, being a tightl* cast language, has strict rules &' regard to the process in &'cdata is stored# $he Java compiler en"orces man* o" these rules as to ho& much storage is

allocated in each data X as to &here data &ill be stored#

$eining Cla++e+:

A class de"inite consists several constructs "or de"ining X declaring the "":7#) Attributes declared either at the start or at the end o" class de"inition, these variables

identi"* the data that is stored in the object# 1bject data can be either primitives or

re"erences to other objects#

=#) onstructor this method de"ines the speci"ics o" object creation#

#) tandard 0ethods theses methods to change or access the private data in an object#

C#) ustom 0ethods these are methods that implement the business rules#

-ig 5H


/ame

Attributes

1perations

or 0ethods

Attributes declaration

onstruction de"inition

stand 0ethods de"initioncustom methods de"inition


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Page

$e+igning Cla++e+:

7#) De"ine class name

*nta(:access]speci"ierS class class]nameS bod*F N

=#) +denti"* Attributes

*nta(:

access]speci"ierS data]t*peS attributesSF #) De"ine onstructor

A constructor method has some "eatures:

constructor method must have the same name as the class name#

constructor method has to de"ine none, one or man* "or a class#

onstructor method do not have a return value#

onstructor method are e(ecuted onl* once at object creation#

*nta(:access]speci"ierS class /ame %argument @istsU)

constructor bod*

Nnote: $he constructor is ver* important method because it is used during the creation

%instantiation) o" an object#

$he ne& 4e*&ord is an operator used to allocate memor* "or the creation o" anobject#

C#) reate tandard 0ethod

0utator %setters) methods used to change data#

*nta(:

access]speci"ierS void set ??? %argument @istssU)

''((( is a "ield variable &'c is assigned &'a speci"ic

value ''in the method bod*#

Accessor %getters) methods used to access or retrieve data#

*nta(:access]speci"ierS return$*peS get ((( %)

''((( is usuall* a "ield variable &hose value is returnedb* ''the method#

/ote: $he accessor method uses the return 4e*&ord at the end o" its de"inition#


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Page C

9#) reate ustom 0ethod

*nta(:access]speci"ierS return]t*peS method /ame %argument@istsU)

''method bod*

N

custom methods are methods that implement the business rules "or &'c the

application is being developed are part o" the class de"inition#

Sample Program No &:

Public class imple lass Public static void main %string args K L)

tudentRecord m*tudent Q ne& tudentRecord %GPearl Ruth DamiasH,GE0P-

>7H)Fm*tudent#set3rade %8#88, 89#9)F

s*stem#out#println%Gtudent /ame:H ! m*tudent#get/ame%))F

s*stem#out#println%G3rade in English:H ! m*tudent#get3radeEng%))Fs*stem#out#println%G3rade in 0ath:H ! m*tudent#get3rade0ath%))F

s*stem#out#println%GAverage 3rade:H ! m*tudent#getAverage%))F

N N

class tudentRecord private tring student+dF

private double gradeEngF A$$R+B.$Eprivate double grade0athF

public tudentRecord %string n, string sid) name Q nF

student+d Q sidF 1/$R.$1R

N

public void main set3rade %double e, double m)F gradeEng Q eFgrade0ath Q mF 0.$A$1R ' E$$ER

N


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Page 9

Public string get/ame%) Return nameF

N

public string gettudent+d%) return tudent+dF

N AE1R ' 3E$$ER

public double get3radeEng%) return gradeEngF

N

public double get3rade0ath%)

return grade0athFN

Public double getAverage%) Double aveF

ave Q %grade0ath ! gradeEng)'=F .$10 0E$;1D

Return aveFN

#*IS e,'orF

#%i+ 4 contains re"erence as the current object being constructed# $his 4e*&ord

represents an instance o" the class in &'c it appears# +t can be used to access class variableX methods#

ample Program /o# =

Public class ellphone

Private string brandF A$$R+B.$E Private string modelF

Public cellphone %) $his#brand Q G/1+AHF 1/$R.$1R $his#model Q GII>>HF

N


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Page I

Public void setBrand %string brand) $his#brand Q brandF

N 0.$A$1R ' E$$ER

public void set0odel %string model) this#model Q modelF

N

public tring getBrand %)

return this#brandF

N AE1R ' 3E$$ER

public tring get0odel %) return this#modelF

N

'' public void Ring %)

'' s*stem#out#println%G 0Y phone is ringingUH)F

'' N .$10'' public void vibrate %) 0E$;1D

'' s*stem#out#println%G 0Y phone is vibratingUH)F

'' N

public class $est public static void main %tring args K L)

cellphone cell7F ''null value "or cell7 variablecellphone cell=Qne& ellphone%)F ''cellphone class value "or cell= variable

cell7Qne& ellphone%)F

cell7#setBrand %G/1+AH)Fcell7#set0odel %GOI9>H)F

s*stem#out#println%G


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Page O

UML $iagram or Sample Program No 5

UML $iagram or Sample Program No &

ellphone

- brand : string

- model : string

cellphone %)

etBrand%brand :

string) voidet0odel%model :

string) void

getBrand%) : stringget0odel%) : string

$E$

main %args : tring K L) void

tudent Record

- name : string

- student +D : string

- gradeEng : double-grade0ath : double

! tudentRecord%)! set3rade%e:double,m:double) void

!get/ame%) : string! gettudent+d%) : string! get3radeEng%) : double

! get3rade0ath%) : double

! getAverage%) : double

im le lass

! main %args : string K L) :

void


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Page

A""A2S

Arra*s are used to represent "i(ed number o" elements o" the same t*pe# $he

entire arra* is stored contiguousl* &ithin the computer2s memor* X is re"erence b* acommon name# each element o" the arra* is distinguished b* the inde( %or subscript)# $he

elements o" the arra* are e(plicitl* initiali6ed to de"ault values based on the arra* t*pe %>

"or-integral t*pes, >#> "or "loat ' double, "alse, "or Boolean X null "or object t*pes)#*nta(:

$*pe arra*/ame K L Q ne& t*pe KlengthL

here:

$*pe data t*pe o" arra*/e& operator "or memor* allocation

@ength si6e o" the arra*#

E(ample:tring names K L Q ne& string K9LF

+llustration:

+nde( - > 7 = C

-C inde() storing# tring values

inside the memor* o" the computer#

Arra, Illu+tration:

*nta(: t*pe arra*/ame Q a, b, c, d,U##nNF

E(amples: int ( K L Q 7, =, , C, 9, INF

Boolean b K L Q true, true, "alseNFDouble grade K L Q , 88, 8, O9, 7>>, I#8NF

tring names K L Q GAnnH, GBenH, GhinaHNF


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Page 8

ACCESSIN6 S#!"IN6 ALUES IN AA"A2S:

*nta(: arra*/em Kinde(L valueF

$he process o" storing values in an arra* is also re"erred to as GpopulatingH thearra*:

E(ample: Representation:

?K>L Q OF

?K7L Q 8F?K=L Q CF

?KL Q 7=F elements

> 7 = inde(

ample Program /o# 7

+mport java#io#F

Public class Arra* mple

public static void main %string args K L) thro&s E(ception B.""eredReader brQne& Bu""eredReader%ne& +nputtreamReader%s*stem#in))F

tring sQ G GF

+nt ( K L Q ne& int K9LF

*stem#out#println%G$his program &ill accept 9 integer:H)FF + (#lenghtF i!!)

*stem#out#println%GPlease enter number: ( K G! + ! G L:H)F

Qbr#readline%)F?KiL Q integer#parse+nt%9)F

N

*stem#out#println%Gn $he numbers areH)FF + (#lenghtF i!!)

*stem#out#println%G( K G! + !HL Q G ! ( KiL)F

N

7=C8O


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N

N


Page C>

ample Program /o#=

lass ;al"Dollars public static void main %string args K L)

intK L Denver Q 79>>>>>I, 77>>>>,=>O9=77>NF

intK L Philadelphia Q ne& int KDenver#lengthLFintK L total Q ne& int KDenver#lengthLF

int averageF

PhiladelphiaK>L Q 79>=>>>>F

PhiladelphiaK7L Q 7O>>>FPhiladelphiaK=L Q =7C>>>F

$otal K>L QDenver ! Philadelphia K>LF$otal K7L QDenver ! Philadelphia K7LF

$otal K=L QDenver ! Philadelphia K=LF

Average Q %totalK>L ! totalK7L ! totalK=L)'F

*stem#out#println%G=>>> production:H !total K>L)F

*stem#out#println%G=>>7 production:H !total K7L)F*stem#out#println%G=>>= production:H !total K=L)F

*stem#out#println%GAverage production:H ! average)F

N

ample Program /o#

lass Rangelass

+nt K L ma4eRange %int lo&er, int upper) +nt arr KL Q ne& int K %upper lo&er) ! 7LF

F + arr#lengthF i!!)

ArrKiL Q lo&er !!:N

return arrF

N


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public static void main %string args K L)

int thearra*KLFRange lass theRange Q ne& Rangelass%)F

N


Page C7

theArra* Q theRange#ma4eRange%7,7>)F

*stem#out#print%G$he arra* is: +H)F

F + theArra*#lengthF i!!)F*stem#out#print%theArra*KiL! G G)F

N

*stem#out#println%G+H)F

N

ample Program /o# C

+mport java#io#FPublic class tudentRecord

public static void main %string args K L) thro&s E(ception

B.""eredReader brQne& Bu""eredReader%ne& +nputtreamReader%s*stem#in))F*stem#out#print%GEnter the number o" record *ou &ant:H)F

+nt number1"Record Q +nteger#parse+nt%br#readline%))F

''declaration o" arra*string namesKL Q ne& tring Knumber1"RecordLF

doubleKL grades Q ne& double Knumber1"RecordLF

*stem#out#println%G


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*stem#out#println%Gearch a student:H)F

*stem#out#println%GEnter the name o" the student:H)Ftring pangalan Q br#readline%)F

everal programming models have evolved to help programmers in carr*ing-outthe process o" problem solving using a computer# $he = o" the most popular models are:

the procedural programming X the object-oriented programming#

P"!CE$U"AL P"!6"AMMIN6

Procedural programming is a techniue o" solving a problem b* brea4ing do&n a

program into smaller pats that are arrange X e(ecuted in a logical seuence# Each o"these smaller solutions is used to per"orm a bloc4 o" codes called "unction#

$his techniue o" programming is also 4no&n as process-oriented programming

since it concentrates on the procedures# ;o&ever, the approach is not ideall* suited "ordeveloping comple( so"t&are since the modules are tightl* inter&oven X interdependent

that it is di""icult to separate "rom one module to another# +n addition to this, the

reusabilit* o" the so"t&are becomes ver* di""icult as comple(it* increases &'in theprocess involved#

!JEC#


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1bject-oriented programming %11P) is a techniue o" solving a problem that usesobjects# $hese objects are created X stored in the computer memor* &'c contains data X

"unctions %instructions ' operations) that per"orms a speci"ic tas4s# +n addition to this,

11P describes the relationships that can be created bet&een these objects# o &hen the

program is e(ecuted, the computer s*stem loads these objects X per"orms operations onthese objects# Basicall*, 11P model describes a program that uses a collection o" objects

interacting &' each other#


Page C

1ne o" the principal advantages o" using object-oriented programming techniue is that itenables programmers to create modules that need not to be changed &hen a ne& t*pe o"

object is added# $his ma4es 11P so"t&are easier to modi"*#

ENE-I#S !- !!P

7#) Reduced so"t&are comple(ities X realistic modeling through the use o" various

techniues such as abstraction X encapsulation %or in"ormation hiding)

Abstraction the process o" pic4ing-out %abstracting) the common

"eatures o" objects X procedures# +t "ocuses on the essential characteristics

o" an object#

Encapsulation the process o" hiding the implementation details o" an

object# +t is also used to combine elements to produce a ne& entit*#

=#) o"t&are reusabilit* b* implementing inheritance# Programs are built that can be used

b* several other applications# o"t&are reusabilit* translates to a saving time X e""ort inso"t&are development, &'c in their results in cost bene"its#

+nheritance allo&s an object to e(tend its char to another object#

#) Resilience to change &' the use o" pol*morphism#

Pol*morphism abilit* to process objects di""erentl* depending on theirt*pe o" class#

ENE-I#S !- USIN6 IN *E"I#ANCE:

7#) Reuse o" prede"ined X &ell-tested classes#

=#) tandardi6ation o" behaviors across a group o" classes

#) Abilit* to use members o" a "amil* o" classes interchanging in methods#


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*nta( "or implementing inheritance:Public class subclass e(tends super class

''attributes or data declarations

''constructor X method de"initionsN


Page CC

P!L2M!"P*ISM

Abilit* to process objects di""erentl* depending on the data t*pe or class#

Abilit* to rede"ined methods "or derived classes#

E(ample:

3iven a base class or superclass shape, pol*morphism enables the programmer tode"ine di""erent circum"erence methods "or an* number o" derived classes, such ascircles, rectangles X triangles# /o matter &hat shape an object is, appl*ing the

circum"erence method to it &ill return the correct results#

IMPLEMEN#IN6 P!L2M!"P*ISM:

7#) 1verloading t&o or more implementations o" essentiall* the same "unctionalit* touse the some name X the t*pe and order o" arguments in the parent class#

ample Program /o# 7

lass tudentRecord

Private tring nameF

Private string student+dFPrivate double gradeF

Private string subjectF

Public tudebtRecord %)


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/ame Q nullF

student+d Q null FN

1verloaded

public tudentRecord %string n, string sid) onstructor

name Q nFstudent+d Q sidF

N


Page C9

Public void set3rade %double g, string s)

3rade Q gF

ubject Q sFN

public void set3rade %string s, double g) grade Q gF 1verloaded

subject Q sF 0ethods

N#

#

#N

ample Program /o# =

lass tudentRecord= Private string nameF

Private string student+dF

Private double gradeF Private string subjectF

Public tudentRecord%) /ame Q nullF

student+d Q nullF

N


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:

: public void displa*3rade%)

s*stem#out#println%Gubject:H ! subject)F 1verridden

s*stem#out#println%G3rade:H ! grade)F 0ethods

N :

:N

class AnotherRecord e(tends tudnetRecord=

private double grade=F

private string subject=


Page CI

Public tudentRecord %)F

: :

N

public void displa*3rade%) s*stem#out#println%Gubject:H ! subject)F

s*stem#out#println%Ggrade:H ! grade)F

s*stem#out#println%Gubject=:H ! subject=)Fs*stem#out#println%Ggrade=:H ! grade=)F

N

: :

N

C!MPA"IS!N: !verloaFing + !verriFing

15ER@1AD+/3 15ERR+D+/3

1verloaded methods supplement T overriding method %largel*)

each other replaces the method it overrides#

1verloaded methods can e(ists, T Each method in a parent class can be


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in an* number, in the same class# overridden at most once in an* one

subclass#

1verloaded methods must have T overriding methods must have argu-

di""erent argument lists# ment lists o" identical t*pe X order

%other&ise the* are simpl* treated asoverloaded methods)#

$he return t*pe o" an overloaded T the return t*pe o" overriding method

method ma* be chosen "reel*# must be identical to that o" the me-

thod it overrides#


Page CO

ample Program /o#

Public class 0*Rectangle Protected double &idthFProtected double lengthF

Public 0*Rectangle %double &idth, double length)

$his#&idth Q &idthF$his#length Q lengthF

N

public 0*Rectangle%) this%7>#>,7>#>)F

N

public string totring%)

string rec Q Gn &idth:H ! this#&idth ! Gn length:H ! this#lengthFreturn recF

N

Nclass 0*Bo( e(tends 0*Rectangle

private double heightF

public 0*Bo(%double &idth, double length, double height)


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super%&idth, length)F

this#height Q heightFN

public 0*Bo( %double height)

super%)F

this#height QheightFN

public 0*Bo(%) this%7>#>)F

N

public string totring%)

string bo( Q super#totring%) ! Gn height:H ! this#heightFreturn bo(F

N

N


Page C

SUPE" e,'orF

ontains a re"erence to the parent-class %superclass) object# +t is used to accessmembers o" a class inherited b* the class in &'c it appears#

#%e A/+tract Cla++ Interace

Abstract class a class contains one or more abstract methods, X there"ore can never be

instantiated# Abstract classes are de"ined so that other classes can e(tend then X ma4ethem concrete b* implementing the abstract methods#

+nter"ace an abstract class that represents a collection o" method de"initions X constant

values# +t can later be implemented b* classes that de"ine this inter"ace &' theGimplementsH 4e*&ord#

A/+tract Cla++:


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An e(ample o" an abstract class the shape class# ince not all the objects in the

&orld can be modeled in the same manner, most real-&orld objects are too abstract toe(ist b* themselves# An abstract class de"ines the common properties X behaviors o"

classes derived X belonging to same 4ind#

*nta( "or Abstract lass:

Abstract class class name S

''abstract method declarations

public abstract return$*pe method/ame%Args@ist)F N

note: All abstract classes are public b* de"ault X cannot be instantiated# onstructors X

static methods cannot be declared as abstract#

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


Page C8

-INALS

Interace

hape

;e(agonircleRectangle


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]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


Page 9>

5ehicle


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*nta( "or +nter"ace:

Abstract inter"ace inter"ace/ame

N

''constant declarations

public "inal $*pe variable/ame Q valueF''abstract method declarations

public abstract return$*pe method/ame %Args@ist)F

note: $he di""erence bet&een an abstract class and an inter"ace is that all methods in

inter"ace are onl* declared, and not all implemented# Also, an inter"ace ma* not have an*

private member "ields unli4e an* abstract classes# All inter"ace "ield variables are "inal b*de"ault#

An* class can implement more than one inter"ace, but can onl* e(tend "rom oneclass#

E.ception+ Stream+ anF -ile+:

E.ception is de"ined as an une(pected error or error condition# $he* are called

e(emptions presumabl* because the* are not usual occurrences the* are Ge(ceptionalH#$he object-oriented techniues to manage such errors comprise the group o" methods

4no&n as e(ception handling#

Potential E.ception+:

7#) +ssues a command to read a "ile "rom a dis4, but the "ile do not e(ist there#

=#) You &rite date to a dis4, but the dis4 is "ull or un"ormatted##) Your program as4s "or user input, but the user enters invalid data#

C#) $he program attempts to divide a value b* 6ero, access an arra* &' a subscript that is

too large, or calculate a value that is too large "or the ans&er2s t*pe#

+n java, there are t&o basic classes o" errors, error and E(emption# $he ascendants

o" both o" these classes came "rom the thro&able class sho&n in the "igure belo

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


Page 97


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1thers

1ther

Error Cla++represents more serious errors "rom &hich *our program usuall* cannot

recover# $hese are errors that *ou probabl* made in *our programs &hen *ou misspelled

a class name or store a reuired class in the &rong "older#hen a program cannot locate a reuired class an Error condition occurs or runs out o"

memor*#

E.ception Cla++it is a less serious error that represents unusual conditions that arise&hile a program is running and "rom &hich the program can recover# ome o" these

errors in E(ception class include using an invalid arra* subscript or per"orming illegal

arithmetic operations#

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


+nternal'ErrorE(ception

1ut1"0emor*E(ception

Error

Arra*inde(1ut1"BoundsE(ception

Arithmetic E(ception

Runtime E(ception

+1 E(ception

E(ception

$hro&able


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Page 9=

ample Program /o# 7

Public class computeError Public static void main%tring argsKL)

+nt numQ7IF

+nt denQ>F+nt resultF

ResultQnum'denF

NN

Error Cla++ represents more serious errors "rom &hich *our program usuall* cannotrecover# $hese are errors that *ou probabl* made in *our programs &hen *ou misspelled

a class name or store a reuired class in the &rong "older# hen a program cannot locatea reuired class an Error condition occurs or runs out o" memor*#

E.ception Cla++ it is a less serious error that represents unusual conditions that arise

&hile a program is running and "rom &hich the program can recover# ome o" these

errors in E(ception class include using an invalid arra* subscript or per"orming illegalarithmetic operations#

ample Program no# 7

Public class computeError

Public static void main%tringargsK L) +nt numQ7IF+nt denQ>F

+nt resultF

ResultQnum'denFN

N

note: You can see that the E(ception is a java#lang#ArithmeticE(ception, &hich is a

subclass o" E(ception# You also get some in"ormation as to the nature o" the error %G'

6eroH), the method that generates the error %omputerError#main), and the "ile and the

line number "or the error %omputerError#java, line 8, *our line number might bedi""erent i" *ou include lines at the beginning o" *our program)#

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


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Page 9

$he most o"ten used error-handling solution has been terminate the o""ending program#

Public class 0athErrorample7 Public static void main%tring argsK L)

+nt numQ7, denomQ>F resultF

+" %denomQQ>)*stem e(it%7)F

ResultQnum'denomF

NN

#r, Catc% anF -inall,

*nta(: public class some0ethod thro&s someE(ception

$r*

''statements that might cause an E(ceptionN

catch%someE(ception and E(cdeption+nstance)

''&hat to do about itN

"inall* ''statements "or cleaning up the state o" the method be"ore %possibl*)

allo&ing control to be passed to a di""erent part o" the programN

''statements here e(ecute even i" there &as no E(ceptionN

note: +" an E(ception occurs during the e(ecution o" the tr* bloc4, then the statementsin the catch bloc4 &ill e(ecute# +" no E(ception occurs &ithin the tr* bloc4, then the catch

bloc4 &ill not e(ecute# $he "inall* bloc4 allo&s *our method to clean up a"ter itsel"

regardless o" &hat happens &ithin the tr* bloc4# .se "inall* bloc4s to close "iles orrelease other s*stem resources# Either &a*, the statements "ollo&ing the "inall* bloc4

e(ecute normall*#

+" a method thro&s an E(ception that &ill be caught, *ou must use the 4e*&ordGthro&sH "ollo&ed b* an GE(ception t*peH in the method header#

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]

$erminates the program


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Page 9C

#*"!IN6 AN$ CA#C*IN6 MUL#IPLE ERCEP#I!NS

+n thro&ing and catching multiple e(ceptions *ou can place man* statements as

*ou &ant &ithin the tr* bloc4 as &ell as catching E(ceptions# +" *ou tr* more than onestatement, onl* the "irst error generating statement thro&s E(ceptions# As soon as the

E(ception occurs, the logic trans"ers to the catch bloc4, &hich leaves the rest o" the

statements in the tr* bloc4 une(ecuted#

0ultiple catch bloc4 is e(amined in seuence until match is "ound "or theE(ception that occurred, and the matching catch bloc4 e(ecutes and each remaining catch

bloc4 is b*passed#

ample Program /o# =

Public class 0ultiple$r*atch Public static void main%tring args KL) thro&s ArithmeticE(ceptionF

+nde(Q1ut1"BoundsE(ception

+nt numQ=>F+nt denQ>F

+nt resultF

+nt K L arra*Q%7>,=>,>,C>)F

$r*

ResultQnum'denResultQarra*KnumL

Ncatch%ArithmeticE(ceptionError)

s*stem#out#println%GError 1ccurred in Arithmetic omputationH)F

Ncatch%inde(1ut1"BoundsE(ception erro)

s*stem#out#println%Error 1ccurred in inde(ingH)F

N

NN

note: 0ultiple$r*atch class declares "our integers and an integer arra* &ith "ourelements in the main%) method, the tr* bloc4 e(ecutes and the "irst statement &ithin thetr* bloc4, an E(ception occurs because the denominator%den) in the divisionproblem is

6ero%>)# $he tr* bloc4 is abandoned and the logic trans"ers to the "irst catchbloc4#

Divisionb* 6ero causes an Arithmetic omputationH# $he second catch bloc4ed iss4ipped#

]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


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Page 99

An +nde(1ut1"BoundE(ception occurs &hen an arra* subscript is not &ithin the

allo&ed range#

ample Program /o#

Public class rite@istample Public void &rite@ist%)

printriter outQnullF

tr* s*stem#out#println%GEntering tr* statementHF

outQne& Printriter%ne&


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Page 9I

ample Program /o# C

+mport java#io#F

lass LF

$r*

*stem#out#println%Gn Enter a line to be saved to dis4:H)F+nt b*tes Q s*stem#in#read%bu"")F

"ile1utputtream "ile1ut Q ne& $1P

7

=

B1$$10Element >

Element 7

Element =

Element


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]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]


Page 9O

$he stac4 class de"ines onl* one constructor, &hich is a de"ault constructor that

creates an empt* stac4# You use this constructor to create a stac4 li4e this#

tac4 s Q ne& tac4%)F

You add ne& elements to a stac4 b* using the push%) method, &hich pushes anelement onto the top o" the stac4#

s#push%G1neH)Fs#push%G$&oH)F

s#push%G$hreeH)F

s#push%G


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Although the stac4 class issn2t uite use"ul, it provides the "unctionalit* "or a ver*

common and established data structure#

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Page 9

UEUES

^ueue is a container li4e the stac4s but ituses "irst-in-"irst-out %


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$his code places si( strings onto ueue, &ith the last string %G3rapesH) remaining

on the top# You remove or return elements bac4 o"" the ueue b* using the deueue%)method#

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meljun cortes manual java programming csci03

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