资源描述：
《application fundamentals——android developers 毕业设计(论文)外文资料翻译》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、毕业设计（论文）外文参考资料及译文译文题目：ApplicationFundamentals --AndroidDevelopers学生姓名：学 号：专 业：计算机科学与技术（NIIT）所在学院：信息技术学院指导教师：职 称：2011年12月19日19ApplicationFundamentals——AndroidDevelopersAndroidapplicationsarewrittenintheJavaprogramminglanguage.TheAndroidSDKtoolscompilethecode—alongwi
2、thanydataandresourcefiles—intoanAndroidpackage,anarchivefilewithan.apksuffix.Allthecodeinasingle.apkfileisconsideredtobeoneapplicationandisthefilethatAndroid-powereddevicesusetoinstalltheapplication.Onceinstalledonadevice,eachAndroidapplicationlivesinitsownsecuritysandbox
3、:TheAndroidoperatingsystemisamulti-userLinuxsysteminwhicheachapplicationisadifferentuser.Bydefault,thesystemassignseachapplicationauniqueLinuxuserID(theIDisusedonlybythesystemandisunknowntotheapplication).Thesystemsetspermissionsforallthefilesinanapplicationsothatonlytheu
4、serIDassignedtothatapplicationcanaccessthem.Eachprocesshasitsownvirtualmachine(VM),soanapplication'scoderunsinisolationfromotherapplications.Bydefault,everyapplicationrunsinitsownLinuxprocess.Androidstartstheprocesswhenanyoftheapplication'scomponentsneedtobeexecuted,thens
5、hutsdowntheprocesswhenit'snolongerneededorwhenthesystemmustrecovermemoryforotherapplications.Inthisway,theAndroidsystemimplementstheprincipleofleastprivilege.Thatis,eachapplication,bydefault,hasaccessonlytothecomponentsthatitrequirestodoitsworkandnomore.Thiscreatesaveryse
6、cureenvironmentinwhichanapplicationcannotaccesspartsofthesystemforwhichitisnotgivenpermission.However,therearewaysforanapplicationtosharedatawithotherapplicationsandforanapplicationtoaccesssystemservices:It'spossibletoarrangefortwoapplicationstosharethesameLinuxuserID,inw
7、hichcasetheyareabletoaccesseachother'sfiles.Toconservesystemresources,applicationswiththesameuserIDcanalsoarrangeto19runinthesameLinuxprocessandsharethesameVM(theapplicationsmustalsobesignedwiththesamecertificate).Anapplicationcanrequestpermissiontoaccessdevicedatasuchast
8、heuser'scontacts,SMSmessages,themountablestorage(SDcard),camera,Bluetooth,andmore.Allapplication
