GoogleAndroid

GoogleAndroid-AComprehensiveIntroductionTechnicalReport:TUB-DAI03/09-01Hans-GuntherSchmidt,KarstenRaddatz,Aubrey-DerrickSchmidt,AhmetCamtepe,andSahinAlbayrakMarch16,2009DAI-LaborderTechnischenUniversitätBerlinProf.Dr.-Ing.habil.SahinAlbayrakTechnischeUniversitätBerlinDAI-LaborInstitutfürWirtschaftsinformatikundQuantitativeMethodenFachgebietAgententechnologieninbetrieblichenAnwendungenundderTelekommunikationSekretariatTEL14Ernst-Reuter-Platz710587BerlinTelefon:[phone]Telefax:[phone]E-mail:[e-mail]://’snewproductanditsfirstattempttoenterthemobilemarket,mighthaveanequalimpactonmobileuserslikeApple’shypedproduct,theiPhone.InthisTechnicalreportwearegoingtopresenttheGoogleAndroidplatform,whatAndroidis,describewhyitmightbeconsideredasaworthyrivaltoApple’siPhone.Wewilldescribepartsofitsinternals,takealookunderthehoodwhileexplainingcomponentsoftheunderlyingoperatingsystem.Wewillshowhowtodevelopappli-cationsforthisplatform,whichdifficultiesadevelopermighthavetoface,andhowdeveloperscanpossiblyuseotherprogramminglanguagestodevelopforAndroidthanthepropagatedlanguageJava.3Contents1Introduction62AboutAndroid82.1WhatIsGoogleAndroid?.........................82.2WhatIstheGoogleAndroidSDK?....................82.3TheGoogleAndroidArchitecture....................92.4Google’sMotivationBehindAndroid..................93TheAndroidSDK103.1GeneralStructureOfTheSDK......................103.2ToolsWithinTheSDK..........................103.3TheAndroidEmulator..........................113.4AndroidDocumentation.........................123.5ADT-AndroidDevelopmentToolsForEclipse.............124TheAndroidOS144.1TheAndroidEmulatorOnOS-level...................144.2TheKernel................................164.3FileystemLayout.............................164.3.1SystemImage...........................174.3.2UserDataImage.........................184.3.3CacheImage...........................194.3.4SDCardImage..........................194.4Android-SpecificDaemons........................195SourceCodeLifeCycleOnAndroid215.1FromJavaSourceCodeToACompiledDexFile............215.2PackagingAllProjectFilesIntoAnAPK................215.3HowToCreateAndDeployAPKsWithoutEclipse...........216FacingDifficultiesInDevelopingOnAndroid236.1DifficultiesInDevelopingDndroidApplications.............236.2DifficultiesDevelopingInC/C++.....................236.3DifficultiesDevelopingInJava......................237InterconnectDaemonandGetProcessList257.1Motivation.................................257.2HandlingInterprocessCommunication..................257.3ArchitectureDesignAndUML-Diagramm................267.4InterconnectDaemon...........................267.5GetProcessList..............................277.6OutOfScope...............................277.6.1WhatDidWeNotImplement?Why?..............277.6.2WhatElseCouldBeDoneBasedOnThisProject?.......294References31ListofFigures1TheGoogleAndroidArchitectureoverview...............92Greetingyouwiththewelcomescreen..................153UML-diagramofGetProcessList.....................264UML-diagramofGetProcessList.....................275UML-diagramofGetProcessList.....................28ListofTables1SDKElements..............................1051IntroductionForsometimenow,twooperatingsystemsformobilephoneshavebeendominatingthemobilemarket:SymbianOSandWindowsMobile.InJanuary2007[1],Apple,asthirdbigcompanytoenterthemobilemarket,intro-ducedtheiPhonerunningthein-housedevelopedoperatingsystemMacOSX.Leavingthegenerationofkeypadsbehing,theiPhonewasoneofthefirstphonestoofferaground-breakingnewtouchpadinterfacewhichworksveryfastandsensitive.This,combinedwithitsappearanceofbothphysicaldeviceandoperatingsystem,resultedinabighypeforApple’snewcashcowiPhone.IncombinationwithiPhonemarket,of-feringthousandsofapplicationswhichcaneasilybedownloadedandinstalled,iPhonehasbecomeamajorsuccessinApple’sproducthistory.Aslastcontestant,Google,famousforitsdominatingwebsearchportal,enteredthemarketwithaLinux-kernel-basedproduct:GoogleAndroid.GoogleAndroid,aLinux-kernel-basedoperatingsystem,comesalongwithaquitenewcredowithinthismarket:itissupposedtobeopen!This,inparticular,meansallelementsusedshallbeprovidedinsourcecodeformsothatdeveloperswillhavethepossiblilitytotakeacloserlookintothesystemtomaybealterittotheirneeds.InordertoguaranteeagreatimpactofGoogleAndroidonthemarket,Googleorganizedseveraldevelopercontestsinordertocreatearichsetofready-to-goapplicationsfortheAndroidplattformbeforetheactualphoneisevenavailableonthemarket,hopingtoenterthecompetitionwithApple’siPhonemarket.AsstrategicpartnersGooglepickedHTCasproviderforthefirstphysicaldevicerunningAndroidandT-MobileastelephoneproviderwhowilloffertheT-MobileG1,thenameofthefirstupcomingdevice,coupledwithacontract,foraconsumer-friendlyprice.MotivationofthisTe