Java Reference
In-Depth Information
Summary
TheAndroidDeveloper'sGuidedefinesAndroidasasoftwarestack(asetofsoftware
subsystems needed to deliver a fully functional solution) for mobile devices. This
stackincludesanoperatingsystem(amodifiedversionoftheLinuxkernel),middle-
ware(softwarethatconnectsthelow-leveloperatingsystemtohigh-levelapps),and
keyapps(writteninJava)suchasawebbrowser(knownasBrowser)andacontact
manager (known as Contacts).
Android presents a layered architecture that includes an application framework
(Activity Manager, Content Providers, Location Manager, Notification Manager,
PackageManager,ResourceManager,TelephonyManager,ViewSystem,andWin-
dowManager),libraries(FreeType,libc,LibWebCore,MediaFramework,OpenGL|
ES,SGL,SQLite,SSL,andSurfaceManager),theAndroidruntime(CoreLibraries
and Dalvik Virtual Machine), and a Linux kernel.
ThearchitectureofanAndroidappdiffersfromthatofanapplicationrunningon
thedesktop.Apparchitectureisbaseduponcomponents(activities,broadcastreceiv-
ers,contentproviders,andservices)thatcommunicatewitheachotherviaintents,are
describedbyamanifest,andmayuseapplicationresources.Collectively,theseitems
are stored in an app package, also known as an APK.
Beforeyoucancreateanapp,youneedtoinstalltheAndroidSDKandanAndroid
platform. Youthenneedtocreate anAVDandstarttheAVDbeforeyoucaninstall
and run your app.
Java7MeetsAndroid describes a single-activity app that presents an image
and a button. The image shows Duke, the Java mascot, over a glowing 7. The
button,labeledWave,startsananimationofDukewavingwhenclicked.Inaddition
to its Java7MeetsAndroid.java source file, this app consists of main.xml ,
strings.xml , duke_wave.xml , and duke0.png through duke9.png ap-
plication resource files. It also has its own AndroidManifest.xml manifest.
Search WWH ::




Custom Search