Đề Tài Tìm Hiểu Hệ Điều Hành Android

Tm hiu v h iu hnh Android 1

[email protected] V Quang Ha Nhm 09A, Lp 07T4

CHNG 1. TNG QUAN V TI ............................................................................... 2

1.1 S lc v cc h iu hnh ............................................................................................. 2

1.2 ti v mc tiu ca ti ............................................................................................. 4

CHNG 2. C S L THUYT ........................................................................................ 5

2.1 Gii thiu chung v hiu hnh android ............................................................................. 5

2.2 Kin trc h iu hnh android ......................................................................................... 7

2.3 H thng tp tin trn h iu hnh android ..................................................................... 12

2.4 So snh gia cc h iu hnh ........................................................................................ 16

CHNG 3. THIT K V XY DNG CHNG TRNH .......................................... 18

3.1 Phn tch chc nng ....................................................................................................... 18

3.2 Xy dng chc nng....................................................................................................... 20

CHNG 4. TRIN KHAI V NH GI KT QU .................................................... 24

4.1 Mi trng trin khai. .................................................................................................... 24

4.2 Kt qu chc nng ca chng trnh .............................................................................. 24

4.3 nh gi v nhn xt ...................................................................................................... 32

CHNG 5. KT LUN V HNG PHT TRIN ...................................................... 33

5.1 Kt lun.......................................................................................................................... 33

5.2 Hng pht trin ............................................................................................................ 33

TI LIU THAM KHO ........................................................................................................ 34

I HC BCH KHOA NNG

KHOA CNG NGH THNG TIN B mn Mng & Truyn Thng

V Quang Ha Nhm 09A, Lp 07T4

CHNG 1. TNG QUAN V TI

1.1 S lc v cc h iu hnh H iu hnh l chng trnh chy trn h thng my tnh, qun l cc ti nguyn trn

my tnh v l mi trng cho cc chng trnh ng dng chy trn n.

Ngy nay, khi nim h iu hnh khng ch l trn my vi tnh m cn c m rng cho

nhiu thit b in t khc chng hn nh in thoi thng minh (smart phone), cc thit b cm

tay PDA....v.v

Nh vy h iu hnh di ng l h iu hnh chy trn h thng my c tnh di ng cao.

Vi c th , h iu hnh di ng phi c nhng kh nng c bit m nhng h iu hnh

thng thng khng c c. Chn hn nh n phi chy trn h thng my c cu hnh my hn

ch v tc b vi x l, b nh s dng, phi chy c n nh lin tc trong mt thi gian di

m ch s dng mt lng in nng nh, trong sut thi gian chy c th duy tr cc kt ni

mng khng dy m bo vic lin lc.

Mt s h iu hnh tiu biu :

o Trn my tnh c nhn : MS DOS, MS WINDOW, MACOS, LINUX, UNIX,

o Trn in thoi thng minh : Android, Sybian, Window Mobile, iPhone OS, BlackBerry, S60, Bada OS, Palm OS.

Ngoi ra cn c cc h iu hnh chy trn mainframe, server, th chp, ...

1) Cc chc nng chnh ca h iu hnh

Qun l chia s ti nguyn.Ti nguyn y l bao gm:

o Ti nguyn phn cng (CPU, B nh, cc thit b IO)

o Ti nguyn phn mm (Cc file, chng trnh dng chung)



To lp mi trng o t ph thuc vo phn cng cc phn mm ng

dng hot ng, phc v ngi dng.

2) Cc thnh phn ca h iu hnh

- Thnh phn qun l tin trnh - Thnh phn qun l b nh - Thnh phn qun l nhp xut - Thnh phn qun l tp tin - Thnh phn bo v h thng - Thnh phn dch lnh - Thnh phn qun l mng

3) Phn loi h iu hnh a. Theo loi thit b m h iu hnh hot ng

- H iu hnh dnh cho my MainFrame - H iu hnh dnh cho my Server - H iu hnh dnh cho my nhiu CPU - H iu hnh dnh cho my tnh c nhn (PC) - H iu hnh dnh cho my PDA - H iu hnh dnh cho my chuyn bit - H iu hnh dnh cho th chp (SmartCard)

b. Theo s user v s chng trnh cng hot ng - H iu hnh n nhim mt ngi dng - H iu hnh a nhim mt ngi dng - H iu hnh a nhim nhiu ngi dng

c. Theo gc ngi dng - Mt ngi dng - Nhiu ngi dng(Mng ngang hng, mng c my ch)

d. Theo hnh thc x l - H thng x l theo l - H thng x l theo l a chng - H thng chia s thi gian - H thng song song - H thng phn tn - H thng x l thi gian thc

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1.2 ti v mc tiu ca ti n Nguyn l h iu hnh ln ny ca chng em c giao ti.

Tm hiu v h iu hnh android, vit chng trnh minh ha.

Android l mt h iu hnh chy trn in thoi di ng c pht trin t nhn linux,

mang nhiu c tnh c trng ca mt h iu hnh di ng nhng vn mang nhng tnh cht

chung ca cc h iu hnh. L mt h iu hnh tr trung, hin i, tuy ra i mun nhng li

c pht trin t linux, rt kinh nghim t nhiu h iu hnh i trc, c tch hp nhiu cng

ngh tin tin v c bit l c pht trin t mt ng trm cng ngh tm c th gii l

Google nn Android sm tm c ch ng ca mnh.

Trong phm vi mt bi bo co, chng em s ch i n 2 vn sau y :

Nghin cu v kin trc h iu hnh android

So snh h iu hnh android vi cc h iu hnh khc bao gm cc h iu hnh

trn my tnh PC v cc h iu hnh di ng khc.

Nghin cu k h thng file trn android

Phn demo, xy dng chng trnh th hin cu trc h thng file trn android v thc hin

mt s thao tc nh to th mc, sao chp, di chuyn, i tn, xem thuc tnh, xem v chnh sa

cc quyn hn trn file i vi ngi dng, nhm ngi dng.



CHNG 2. C S L THUYT

2.1 Gii thiu chung v hiu hnh android Android l mt h iu hnh di ng da trn nn tng linux phin bn 2.6 dnh cho cc

dng in thoi SmartPhone. u tin c ra i bi cng ty lin hp Android, sau c

Google mua li v pht trin t nm 2005 v tr thnh mt h iu hnh di ng m ngun m,

min ph, mnh m v c a chung cao trn th gii.

H iu hnh android mt h iu hnh rt mnh mnh, c bo mt cao, h tr c nhiu

cng ngh tin tin nh 3G, GPS, EDGE, Wifi.. tng thch vi nhiu phn cng, h tr nhiu

loi b nhp d liu nh keyboard, touch v trackball. Android l h iu hnh di ng nn c kh

nng kt ni cao vi cc mng khng dy. H tr cng ngh OpenGL nn c kh nng chi cc

phng tin media, hot hnh cng nh trnh din cc kh nng ha khc cc tt, l tin

pht trin cc ng dng c giao din phc tp chng hn nh l cc tr chi.

Android lin tc c pht trin, mi bn cp nht t google l mi ln android c ti u

ha hot ng tt hn, nhanh v n nh hn, h tr thm cng ngh mi. Chng hn nh theo

mt nh gi th android phin bn 2.2 hot ng nhanh hn bn 2.1 ti 450%. Hin nay, phin

bn mi nht 2.3 pht hnh ngy 6/12/2010 v ang tip tc c cp nht.

Nm 2008, h iu hnh android chnh thc m ton b m ngun, iu cho php

cc hng in thoi c th em m ngun v ty chnh, thit k li sao cho ph hp vi mi mu

m in thoi ca h v iu quan trng na l h iu hnh m ny hon ton min ph, khng

phi tr tin nn gip h tit kim kh ln chi ph pht trin h iu hnh. Nhng iu l cc

k tt khng ch i vi cc hng sn xut in thoi nh m ngay c vi nhng hng ln nh

Samsung, HTC....

Vi Google, v android hon ton min ph, Google khng thu tin t nhng hng sn xut

in thoi, tuy khng trc tip hng li t android nhng b li, nhng dch v ca hng nh

Google Search, Google Maps,... nh c android m c th d dng xm nhp nhanh vo th trng

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di ng v mi chic in thoi c sn xut ra u c tch hp hng lot dch v ca Google.

T hng c th kim bi, ch yu l t cc ngun qung co trn cc dch v .

Vi cc nh pht trin ng dng (developers), vic h iu hnh android c s dng ph

bin ng ngha vi vic h c th thoi mi pht trin ng dng trn nn android vi s tin tng

l ng dng s c th chy c ngay trn nhiu dng in thoi ca cc hng khc nhau. H t

phi quan tm l ang pht trin cho in thoi no, phin bn bao nhiu v nn tng android l

chung cho nhiu dng my, my o Java chu trch nhim thc thi nhng ng dng ph hp

vi mi dng in thoi m n ang chy. Tt c cc chng trnh ng dng c vit bng ngn

ng Java kt hp vi XML nn c kh nng kh chuyn cao.

Mt s hng sn xut in thoi c s dng h iu hnh android tiu biu :

HTC vi cc dng Desire HD, Evo 4G, DROID ERIS, Desire Z, Hero, Desire,

Tattoo, Wildfire, Droid Incredible, Legend, Magic, Google Nexus One, Dream,

Aria, Paradise

LG vi cc dng GT540 Optimus, Optimus Chic E720, Optimus One P500,

GW620, Optimus Z, Optimus Q, KH5200 Andro-1, GW880, C710Aloha

MOTOROLA vi cc dng MILESTONE 2, BACKFLIP, Droid XTreme,

MT710 ZHILING, MILESTONE, XT720 MOTOROI, A1680, XT800

ZHISHANG, DEFY, CHARM, XT806...

SAMSUNG vi cc dng my I9000 Galaxy S, Galaxy Tab, Epic 4G, i5510,

I5500 Galaxy 5, I7500 Galaxy, I5800 Galaxy 3, M110S Galaxy S, I6500U

Galaxy, Galaxy Q, I5700 Galaxy Spica, I8520 Galaxy Beam, I909 Galaxy S

SONY : XPERIA X10, XPERIA X10 mini, XPERIA X8

ACER vi cc dng my beTouch T500, Liquid E, Stream, Liquid, beTouch

E110, beTouch E130, beTouch E400, beTouch E120, Liquid Metal

Ngoi ra cn nhiu hng in thoi va v nh khc na cng s dng h iu

hnh android trong sn phm ca mnh....



2.2 Kin trc h iu hnh android H iu hnh android c 4 tng t di ln trn l tng ht nhn Linux (Phin bn 2.6),

tng Tng Libraries & Android runtime , Tng Application Framework v trn cng l tng

Application.

1. Tng ht nhn Linux (Linux Kernel layer)

H iu hnh android c pht trn da trn ht nhn linux, c th l ht nhn linux phin

bn 2.6, iu c th hin lp di cng ny. Tt c mi hot ng ca in thoi mun thi

hnh c th u c thc hin mc cp thp lp ny bao gm qun l b nh (memory

management), giao tip vi phn cng (driver model), thc hin bo mt (security), qun l tin

trnh (process).

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Tuy c pht trin da vo nhn linux nhng thc ra nhn linux c nng cp v sa

i rt nhiu ph hp vi tnh cht ca nhng thit b cm tay nh hn ch v b vi x l,

dung lng b nh, kch thc mn hnh, nhu cn kt ni mng khng dy...

Tng ny c cc thnh phn ch yu :

Display Driver : iu khin vic hin th ln mn hnh cng nh thu nhn nhng iu khin ca ngi dng ln mn hnh (di chuyn, cm ng...)

Camera Driver : iu kin hot ng ca camera, nhn lung d liu t camera tr v.

Bluetooth Driver : iu khin thit b pht v thu sng Bluetooth.

USB driver : Qun l hot ng ca cc cng giao tip USB

Keypad driver : iu khin bn phm

Wifi Driver : Chu trch nhim v vic thu pht sng wifi

Audio Driver : iu khin cc b thu pht m thanh, gii m cc tnh hiu dng audio thnh tn hiu s v ngc li

Binder IPC Driver : Chu trch nhim v vic kt ni v lin lc vi mng v tuyn nh CDMA, GSM, 3G, 4G, E m bo nhng chc nng truyn thng c thc hin.

M-System Driver : Qun l vic c ghi... ln cc thit b nh nh th SD, flash

Power Madagement : Gim st vic tiu th in nng.

2. Tng Library v android runtime

Phn ny c 2 thnh phn l phn Library v Android Runtime

a. Phn Libraries. Phn ny c nhiu th vin c vit bng C/C++ cc phn mm c th s dng, cc th vin c tp hp thnh mt s nhm nh :

Th vin h thng (System C library) : th vin da trn chun C, c s dng ch bi h iu hnh



Th vin Media (Media Libraries) : C nhiu codec h tr vic pht v ghi cc loi nh dng m thanh, hnh nh, video thng dng.

Th vin web (LibWebCore) : y l thnh phn xem ni dung trn web, c s dng xy dng phn mm duyt web (Android Browse) cng nh cc ng dng khc c th nhng vo. N cc k mnh, h tr c nhiu cng ngh mnh m nh HTML5, JavaScript, CSS, DOM, AJAX..

Th vin SQLite : H c s d liu cc ng dng c th s dng.

.....

b. Phn Android runtime

Phn ny cha cc th vin m mt chng trnh vit bng ngn ng Java c th hot ng. Phn ny c 2 b phn tng t nh m hnh chy Java trn my tnh thng. Th nht l cc th vin li (Core Library) , cha cc lp nh JAVA IO, Collections, File Access. Th hai l mt my o java (Dalvik Virtual Machine) . Mc d cng c vit t ngn ng Java nhng mt ng dng Java ca h iu hnh android khng c chy bng JRE ca Sun (nay l Oracle) (JVM) m l chy bng my o Dalvik do Google pht trin.

3. Tng Application Framework.

Tng ny xy dng b cng c - cc phn t mc cao cc lp trnh vin c th nhanh chng xy dng ng dng. N c vit bng Java, c kh nng s dng chung tit kim ti nguyn.

y l mt nn tng m, iu c 2 iu li:

c. Vi cc hng sn xut in thoi : C th ty bin ph hp vi cu hnh in thoi m h sn xut cng nh c nhiu mu m, style hp th hiu ngi dng. V th nn tuy cng chung nn tng android m in thoi ca Google c th khc hn vi Motorola, HTC, T-Mobile, Samsung...

d. Vi lp trnh vin : Cho php lp trnh vin c th s dng cc API tng trn m khng cn phi hiu r cu trc bn di, to iu kin cho lp trnh vin t do sng to bi v ch cn quan tm n ni dung m ng dng h lm vic. Mt tp hp API rt hu ch c xy dng sn nh h thng nh v, cc dch v chy nn, lin lc gia cc ng dng, cc thnh phn giao din cp cao ...

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Gii thiu mt s thnh phn ca phn ny :

a. Activity Manager : Qun l cc chu k sng ca mt ng dng cng nh cung cp cng c iu khin cc Activity.

b. Telephony Manager : Cung cp cng c thc hin vic lin lc nh gi in thoi

c. XMPP Service : Cung cp cng c lin lc trong thi gian thc

d. Location Manager : Cho php xc nh v tr ca in thoi thoi da vo h thng nh v ton cu GPS v Google Maps.

e. Window Manager : Qun l vic xy dng v hin th cc giao din ngi dng cng nh t chc qun l cc giao din gia cc ng dng.

f. Notication Manager : Qun l vic hin th cc thng bo (nh bo c tin nhn, c e-mail mi..)

g. Resource Manager : Qun l ti nguyn tnh ca cc ng dng bao gm cc file hnh nh, m thanh, layout, string. (Nhng thnh phn khng c vit bi ngn ng lp trnh)

h. .....

4. Tng Application :

y l lp ng dng giao tip vi ngi dng, bao gm cc ng dng nh :

Cc ng dng c bn, c ci t i lin vi h iu hnh l gi in(phone), qun l danh b(Contacts), duyt web (Browser), nhn tin (SMS), lch lm vic (Calendar), c e-mail (Email-Client), bn (Map), quay phim chp nh (camera)...

Cc ng dng c ci thm nh cc phn mm chng khon (Stock), cc tr chi (Game), t in...

Cc chng trnh c cc c im l :



Vit bng Java, phn m rng l apk

Khi mi ng dng c chy, n c mt phin bn Virtual Machine c dng ln phc v cho n. N c th l mt Active Program : Chng trnh c giao din vi ngi s dng hoc l mt background : chng trnh chy nn hay l dch v.

Android l h iu hnh a nhim, iu c ngha l trong cng mt thi im, c th c nhiu chng trnh cng chy mt lc, tuy nhin, vi mi ng dng th c duy nht mt thc th (instance) c php chy m thi. iu c tc dng hn ch s lm dng ti nguyn, gip h thng hot ng tt hn.

Cc ng dng c gn s ID ca ngi s dng nhn phn nh quyn hn khi s dng ti nguyn, cu hnh phn cng v h thng.

Android l mt h iu hnh c tnh m, khc vi nhiu h iu hnh di ng khc, android cho php mt ng dng ca bn th ba c php chy nn. Cc ng dng ch c mt hn ch nh l n khng c php s dung qu 5~10% cng sut CPU, iu nhn trnh c quyn trong vic s dng CPU.

ng dng khng c im vo c nh, khng c phng thc main bt u.

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2.3 H thng tp tin trn h iu hnh android Trong phm vi mt bi tm hiu v h iu hnh, em ch xin tm hiu r mt vn ca h

iu hnh android l vn qun l h thng tp tin. Phn ny c im thun li tm hiu

l v c pht trin t nhn linux nn h thng tp tin trn android cc k ging h thng tp

tin trn linux nh l v cch t chc, nhng quyn hn ca ngi s dng ln file...

a. Tng quan v h thng file trn Android : - Trong android, cc file c t chc thnh cc th mc, theo m hnh phn cp. Tham

chiu n mt file bng tn v ng dn. Cc cu lnh thao tc file cho php thc hin

cc chc nng nh dch chuyn, sao chp ton b th mc cng vi cc th mc con cha

trong n

- C th s dng cc k t, du gch di, ch s, du chm v du phy t tn file.

Khng c bt u mt tn file bng du chm hay ch s. Nhng k t khc nh /, ?,

*, l k t c bit c dnh ring cho h thng. Chiu di ca tn file c th ti 256 k

t. Trong h iu hnh android c s phn bit tn file ch hoa v ch thng, iu c

ngha l trong cng 1 th mc c th tn ti nhng file c tn l File, FILE, file.. v chng

l nhng file khc nhau..

- Tt c cc file trong android c chung cu trc vt l l chui cc byte (byte stream). Cu

trc thng nht ny cho php android p dng khi nim file cho mi thnh phn d liu

trong h thng. Th mc cng nh cc thit b c xem nh file. Chnh vic xem mi th

nh cc file cho php android qun l v chuyn i d liu mt cch d dng. Mt th

mc cha cc thng tin v th mc, c t chc theo mt nh dng c bit. Cc thnh

phn c xem nh cc file, chng c phn bit da trn kiu file: ordinary file,

directory file, character device file, v block device file.

b. Cc kiu file trn android: - Trong nhiu h iu hnh nh window, ngi ta phn bit r file (tp tin) v folder (hay

directory : th mc) l 2 thnh phn khc hn nhau. Tuy nhin trn h iu hnh android



(cng nh linux) th coi directory cng l file v n l mt loi file c bit. Thc t cn

mt s loi file na c th lit k theo bng sau :

Ch ci biu din Kiu file

d Th mc (Directory)

b File kiu khi (block-type special file)

c File kiu k t (character-type special file)

l Lin kt tng trng (symbolic link)

p File ng ng (pipe)

s Socket

- File bnh thng (regular file)

Hnh 2: Bng lit k mt s kiu file trong Linux

c. T chc quyn s hu v quyn hn trn file: Tng t trn h thng linux, trn h iu hnh android, mt file c th lin

kt vi mt ngi s dng v mt nhm ngi s dng. S lin kt l mt tp hp cc quyn hn truy cp bao gm quyn c php c (read), c php ghi (write) v c php thc thi (execute).

C th nh sau: Mt file s c nhng quyn hn tng ng vi 9 k t theo mu sau : Vi k t r w x ngha l c quyn tng ng vi k t vit tt , - ngha l khng c quyn hn . Owner Owner Group Other r/- w/- x/- r/- w/- x/- r/- w/- x/-

3 k t u tin l quyn hn ch nhn file

3 k t gia l quyn hn ca nhm ti khon s hu file

3 k t cui l quyn hn ca nhng ngi khng thuc nhm s hu file.

V d : Mt file c dy k t biu din quyn hn l rwxr-xrth iu c

ngha :

3 k t u l rwx : Ch nhn c th c, ghi v thc thi file

3 k t tip theo l r-x th nhm ti khon s hu file c quyn c v thc thi file

ch khng c quyn ghi, chnh sa file.

3 k t cui l r-- ngha l nhng ngi khng s hu file ch c php c m

khng th chnh sa hay thc thi file.

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Trn h thng android, bit xem c quyn hn , ta c th s dng cu lnh ls l d.

V d : ls -l -d /mnt/sdcard/QuangHoa xem quyn hn ca file /mnt/sdcard/QuangHoa

th c th tr v kt qu nh sau

d---rwxr-x system sdcard_rw 2010-12-29 21:00 QuangHoa

Th nhng thng tin c th ly v l :

o K t u tin l ch d : vy file c kiu l th mc hay l file bao hm o Chui ghi quyn hn l ---rwxr-x th c ngha

(---)Ngi s hu khng c php c, ghi, thc thi file

(rwx) Nhm ti khon s hu c php c, ghi, thc thi file

r-x : Nhng ngi khng s hu file c php c v thc thi file nhng

khng c php chnh sa hay ghi ln file.

o Chui miu t file : sdcard_rw ngha l y thuc thit b th nh sd, c v ghi c.

o 2010-12-29 21:00 Thi gian chnh sa ln cui o QuangHoa : tn ca file. Ngoi ra c 2 lnh khc cng hu dng l lnh chown thay i quyn s hu file,

lnh chmod thay i quyn hn lin quan n file v lnh chgrp thay i nhm

ngi s hu file.

d. Cy th mc trn h iu hnh android: Th mc (hay c th gi l file) root l th mc gc ca tt c cc file th

mc cn li. Di n c cha mt s file th mc h thng. Mi th mc (tr th mc root) u c mt th mc cha cha n, bn thn n cng c th c nhiu file th mc con. Cu trc c th m t bng mt cy th mc c dng nh sau :

/root

var ect mnt system cache

lost+found font lib app bin framework



Gii thiu mt vi th mc tiu biu : o /(root) : L th mc gc. L th mc duy nht khng c th mc cha

o / mnt : th mc cha thit b lu ng (removeable)

o /system : cha nhng thnh phn c bn nht ca h thng

o /ect : cha nhng file cu hnh ca h thng, n cc k quan trng v s hot ng ca h thng u b chi phi nhng file cu hnh ny.

o /system/lost+found : cha nhng tp tin b mt lc khi ng my

o /system/font : cha nhng font ch hin th c

o /system/lib : cha cc th vin cc phn mm hot ng (cc phn mm vit bng ngn ng java)

o /system/app : cha cc file apk ca phn mm. (Cc file ci t ng dng, kiu nh MSI trong window hay dev trong Linux)

o /system/bin : Cha cc chng trnh ni tr ca h thng.

o ....

-

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2.4 So snh gia cc h iu hnh 1) So snh gia h iu hnh di ng v h iu hnh trn

desktop. Ging nhau v bn cht h iu hnh, nhng thnh phn li h iu hnh.

Khc nhau :

o H iu hnh di ng : hot ng trn cc thit b nh gn, hn ch nht l v vn nng lng. Pin th c hn, v th tt c cc thnh phn trn thit b

u phi ti u tit kim pin, iu ny sinh nhiu mu thun vi nhu

cu s dng ca ngi dng.

Mn hnh cng ln v cng sng th s tn in cng nhiu.

B nh ln th chi ph v in cng s cao.

B vi x l cng nhanh th cng tn in.

iu cha k n vic thit b di ng th phi nh gn, nh nhng,

v vy cng nng vic phi ti u phn cng.

Khi h iu hnh di ng cng c trch nhim phi ti u hot

ng ca mnh tit kim nng lng mt cch ti a.

N phi qun l cc ng dng khng cc ng dng chy chim

qu nhiu ti nguyn, trnh s c quyn, xung t, tranh chp ti

nguyn gia cc ng dng trong khi cc h iu hnh chy desktop

th t ch hn. H iu hnh di ng lun c b cng c qun l

in nng s dng trong my, trong nhng tnh hung cn thit th

h thng s t tt nhng ng dng khng cn thit duy tr cc

chng trnh cn thit hn hot ng.

a s cc h iu hnh trn desktop u cho php nhiu ng dng

chy ng thi (a nhim) v kh t do. Trong khi , cc h iu



hnh chy trn di ng thng khng cho php chy a nhim,

hoc c a nhim th cc ng dng b gii hn kh nhiu.

o Vic hin th giao din trn mt khung hnh nh cng iu kh khn hn so vi h iu hnh chy trn desktop, thng th trn h iu hnh di ng gn

nh khng c giao din ca s cho php nhiu ng dng cng hin th mt

lc m ch l mt giao din m trn mi thi im ch hin th mt giao

din ca mt ng dng m thi.

o H iu hnh di ng phi c kh nng hot ng lin tc khng ngng ngh m bo lin lc, m bo kt ni ca thit b ti mng khng dy cn kt

ni trong khi vn di chuyn. V th cn c thit k c bit hn so vi h

iu hnh trn desktop.

2) So snh h iu hnh android vi cc h iu hnh di ng khc.

Ging nhau : u l h iu hnh di ng nn mang y bn cht ca h iu

hnh di ng ni chung. ( cp trn)

Khc nhau :

o Android l h iu hnh m ngun m v min ph trong khi cc h iu hnh di ng cn li u l ngun ng v c ph (khi mt hng th hai s

dng)

o Android c pht trin t nhn linux do n c th chy tt trn nhiu dng in thoi khc nhau. C tng thch cao vi cc loi phn cng

khc nhau nhiu hn so vi cc h iu hnh di ng cn li.

o Cc ng dng chy trn android c vit bng Java trong khi , ng dng trn cc h iu hnh khc ch yu l vit bng C/C++/Object C. Ngay c symbian c h tr Java th

cng khc so vi android, trong khi h iu hnh android s dng my o Java l Dalvik

VM do chnh Google pht trin th Symbian li s dng my o Java l J2ME ca Sun.

I HC BCH KHOA NNG



CHNG 3. THIT K V XY DNG CHNG TRNH

3.1 Phn tch chc nng Vi yu cu gii thiu, demo cho h thng qun l tp tin trn android, chng trnh chng

em xy dng s c cc chc nng nh sau :

1) Hin th mt list bao gm cc file trong mt th mc. Khi ngi dng chn 1 file

trong :

a. Nu file l file bao hm (th mc) th chuyn list hin th danh sch

file trong th mc .

b. Nu file l file thng thng th m file bng chng trnh thch

hp chng hn nh file hnh nh th m chng trnh xem nh, file nhc th

m chng trnh chi nhc...

2) Ci t mt menu cho php ngi dng chn cc chc nng nh sau :

Properties : Xem v sa cha thuc tnh ca file Delete : Xa file Copy : t file chun b sao chp Cut : t file chun b di chuyn sang ni khc Paste : Thc hin lnh sao chp hoc di chuyn file t trc . Rename : i tn file Create new directory : To th mc mi (ti th mc hin hnh) Refresh : Cp nht li danh sch file Go home : Tr v th mc gc (/) Go up : Tr ln th mc cha (C th dng phm back trn in thoi

thc hin nhanh lnh ny) Exit : Thot chng trnh About : Xem gii thiu



Android Explorer

Hin th danh sch file

To th mc

Sao chp file

Di chuyn file

i tn file

Xa file

i quyn hn trn file Xem thuc tnh

M file bng chng trnh

lin kt i th mc

hin hnh

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3.2 Xy dng chc nng 1) To danh sch file trong mt th mc

2) M chng trnh lin kt

Bt u Ly danh sch file trong th mc

Cn file cha x l

Ly 1 file cha x l

Da vo kiu file v phn m rng ca file t biu tng thch hp Kt thc

Hin th ng

Sai

Bt u

Kt thc

Ly chui nh kiu lin kt vi file

To i tng Itent. Chun b cc tham s bao gm kiu activity, hnh ng, d liu truyn vo

Khi ng activity



3) Xem v sa thuc tnh ca file

a. Xem thuc tnh file

b. i thuc tnh file

ng

ng

Bt u

Kt thc

Thc thi lnh ls

InputStream v ErrorStream cha sn sng

Ch i

Sai

Bo li

Sai

c inputstream

Tch thng tin

Hin th kt qu

InputStream sn sng

ng

Bt u

Kt thc

Thc thi lnh chmod

InputStream v ErrorStream cha sn sng

Ch i

Sai

Sai

Bo li

ng ErrorStream sn sng

Nhn yu cu

I HC BCH KHOA NNG



4) Xa file

5) Sao chp file

Sai

ng

Sai

Bt u:

Kt thc

Cn file trong danh sch

Copy file ti ch

File cn xa l file bao hm

To danh sch file

File hin ti l file bao hm

copy file hin ti ti ch

ng

Sai

ng

To file ch bao hm

Bt u:

Kt thc

Cn file trong danh sch

Xa file cn xa

File cn xa l file bao hm

To danh sch file

File hin ti l file bao hm

Xa file hin ti

ng

ng

Sai

ng Sai



6) Di chuyn file v i tn file

Hai chc nng ny java h tr kh tt ri, nn khng xy dng li na, s dng phng

thc rename t File f1 sang File f2. Nu f1 v f2 cng chung th mc th l chc nng rename,

nu khc th mc th l phng thc di chuyn file.

I HC BCH KHOA NNG



CHNG 4. TRIN KHAI V NH GI KT QU

4.1 Mi trng trin khai. Chng trnh c thc hin trn :

H iu hnh Microsoft Window 7

IDE : Eclipse Helios & ADT Plugin

Android SDK, Plasform Android 2.2, API 8, revision 2

4.2 Kt qu chc nng ca chng trnh Sau y l kt qu demo chy chng trnh :

Giao din chnh, xem danh sch file. Hin th menu...



Xem menu n. Chn menu more hin th

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Xem hnh nh khi m file c ui jpg, jpe, bmp...

Chi nhc khi m file mp3



Khung thuc tnh ca file khi chn 1 file v chn menu Properties

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Khung thuc tnh th mc khi chn 1 th mc v chn menu Properties



Thay i quyn hn ca file khi bm button Change permission t hp thoi properties

i tn file khi chn file v chn chc nn rename t menu

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Chn lnh xa file t menu

To th mc mi



Hp thoi copy file khi yu cu copy file

Hp thoi gii thiu.

I HC BCH KHOA NNG



4.3 nh gi v nhn xt Android l mt h iu hnh di ng hin i, c tim nng pht trin cao. Hin nay s

dng rng ri nhiu hng in thoi v thc s tr thnh mt tp on in thoi mnh m

khi cnh tranh vi nhng dng in thoi khc nh iPhone, Window Phone, Sysbian..

Android c ngun gc t nhn Linux nn c tha hng nhng c tnh qu bu ca

linux, nht l v bo mt v hiu nng hot ng cao. Khng nhng th, t nhn linux c

ti u, ci thin ph hp vi h thng in thoi nn n c kh nng ty bin, tng thch cao

vi nhiu mu in thoi ca nhiu hng khc nhau.

H iu hnh android c tch hp nhiu cng ngh hin i, h tr phn cng tt, lin

tc c cp nht nhng phin bn mi hn, hot ng tt hn. C nhiu API hu ch cho cc nh

pht trin phn mm, nh pht trin ROM c th xy dng nn nhiu ng dng, h thng khc

nhau.

Android l h iu hnh a nhim mt ngi dng. Tnh a nhim cho php cng mt thi

gian, ngi dng c th chy c nhiu nhiu ng dng lm c nhiu vic khc nhau. Tuy

nhin, mi ng dng trn android th ch c php chy vi mt thc th m thi.

H thng qun l tp tin trong android l c pht trin t linux nn c nhiu c im

ging vi h thng qun l tp tin trn linux. l nhng c im v quy tc t tn file, ng

dn th mc, h thng cy th mc, nhng th mc c trng, h thng quyn hn ca file i vi

ngi/ nhm s dng trn h thng. Cng ging nh linux, trn android c th thc thi nhiu lnh

lin quan n h thng file nh chmod, chown, chgrp... chnh sa thuc tnh, h thng quyn

hn trn file.



CHNG 5. KT LUN V HNG PHT TRIN 5.1 Kt lun

Nhng kt qu t c

Biu din c h thng file trn android. Xem c cu trc ca cy th mc

mt cch trc quan. S dng chng trnh c th ni l d dng v danh sch th

mc d nhn, menu chn c xy dng sn.

Xy c nhiu chc nng thao tc vi file nh xem v chnh sa quyn hn

file, sao chp, di chuyn, i tn, xa file.

Lin kt file vi chng trnh ci t, iu cho php m file nhc, video,

hnh nh vi chng trnh c trong my.

Nhng mt hn ch

Chng trnh c xy dng trn emulator m phng ch cha thc s chy

trn phn cng tht.

Cng v ch chy trn emulator nn chc nng chnh sa quyn hn thc hin

cha c tt do khng ng nhp bng ti khon tht.

5.2 Hng pht trin

Xy dng nhiu chc nng tch hp hn x l file

Xy dng ng dng c ty bin hn v giao din, chc nng thc hin

Chy c tht trn emulator c kt qu thc t hn.

I HC BCH KHOA NNG



TI LIU THAM KHO [1] Trn H Thy Tin. Gio trnh nguyn l h iu hnh. i hc Bch khoa Nng,

2009.

[2] Mark L. Murphy. The Busy Coder's Guide to Android Development. CommonsWare, LLC

[3] Mark L. Murphy. Beginning Android Apress

[4] Sayed Y. Hashimi v Satya Komatineni Pro Android Appress

[5] Trang pht trin android http://developer.android.com/

Documents

Đề Tài Tìm Hiểu Hệ Điều Hành Android