外文原文EJB3DEPLOYMENTUNTILNOW,THISBOOKHASFOCUSEDONHOWTOBUILDEJBS,JAVAPERSISTENCEAPIJPAENTITIES,ANDTHEIRCLIENTS,FOREXPLOITINGTHESURROUNDINGENTERPRISESERVICESOFFEREDBYTHEEJBCONTAINERINJAVAEEPARLANCE,THESETASKSFALLUNDERTHEROLEOFAPPLICATIONCOMPONENTPROVIDER,WHICHISREFERREDTOHERESIMPLYASTHEPROVIDERINTHISCHAPTER,WEEXPLORETHETOPICSTHATSURROUNDTHEPROCESSOFPACKAGINGYOURCOMPONENTSINTOMODULESANDLIBRARYCOMPONENTS,BINDINGEXTERNALREFERENCESDECLAREDINYOURJAVAEECOMPONENTSTOACTUALRESOURCESINYOURSERVERENVIRONMENT,ANDSENDINGITALLOFFTOANAPPLICATIONSERVERSOTHATTHECOMPONENTSCANBEEXECUTEDATRUNTIMEBYANAPPLICATIONTHESERESPONSIBILITIESAREHANDLEDBYTHEJAVAEEROLESOFTHEAPPLICATIONASSEMBLERTHEASSEMBLERANDTHEAPPLICATIONDEPLOYERTHEDEPLOYERWHILEINPRACTICEITISCOMMONORASINGLEINDIVIDUALTOPERFORMONEORMOREOFTHESEROLES,ORFORMANYPEOPLETOPERFORMANYSINGLEROLE,FORTHEPURPOSEOFEXPLAININGTHESETOPICSWEWILLPARTITIONTHEDEPLOYMENTTASKSINTOSTAGESTHATCORRESPONDTOTHESEDESIGNATEDROLESWEWILLEMPHASIZEEJBANDJPAENTITYCOMPONENTS,BUTALSOTOUCHONDEPLOYMENTOFTHEOTHERJAVAEEMODULETYPESWEBAPPLICATIONMODULES,APPLICATIONCLIENTS,ANDRESOURCEADAPTERSWEWILLALSOLOOKATTHERELATIONSHIPBETWEENTHEJAVAEESERVERANDTHEFOURJAVAEECONTAINERSTHATITSUPPORTS,ANDEXPLORESOMEOFTHESERVICESTHATAREPROVIDEDBYAJAVAEESERVERFOLLOWINGABRIEFOVERVIEWOFTHEDEPLOYMENTTASKS,INWHICHWEINTRODUCEMUCHOFTHEDEPLOYMENTTERMINOLOGY,WEOFFERALOOKATTHEJAVAEEINFRASTRUCTURECOMPONENTSTHEJAVAEESERVERANDCONTAINERSTHATSUPPORTDEPLOYMENTWEEXPLORETHEDIFFERENTTYPESOFJAVAEEMODULESANDHOWTHEYFITTOGETHER,ANDHOWYOUSPECIFYTHEDEPLOYMENTDESCRIPTORSMETADATAFILESTHATDEFINEEACHMODULEASECTIONONLIBRARYCOMPONENTSEXPLAINSHOWTODECLARECLASSPATHDEPENDENCIESBETWEENJAVAEEMODULESANDLIBRARYCOMPONENTSWETHENPROVIDEAMOREDETAILEDEXAMINATIONOFTHEASSEMBLERANDDEPLOYERROLES,ANDCONCLUDEWITHTHEDEPLOYMENTREQUIREMENTSTHATARESPECIFICTOEJBMODULESANDJPAPERSISTENCEUNITSAFTERREADINGTHISCHAPTER,YOUSHOULDHAVEAGOODUNDERSTANDINGOFHOWTODOTHEFOLLOWINGGROUPYOUREJB,JPA,ANDOTHERAPPLICATIONCOMPONENTSINTOJAVAEEMODULESANDLIBRARYCOMPONENTSRESOLVENAMINGCOLLISIONSANDREDUNDANCIESFOUNDINEXTERNALREFERENCESPACKAGEAJAVAEEAPPLICATIONCONSISTINGOFONEORMOREJAVAEEMODULESANDLIBRARYCOMPONENTSDECLARECLASSPATHDEPENDENCIESBETWEENMODULESANDLIBRARIESBINDEXTERNALREFERENCESTOPHYSICALRESOURCESINTHEAPPLICATIONSERVERENVIRONMENTANOTEONDEPLOYMENTTOOLSTHISCHAPTERPROVIDESSOMEEXAMPLESOFHOWTOSTRUCTUREYOURAPPLICATIONARCHIVES,BUTITISASSUMEDTHATYOUHAVEACCESSTOSOFTWARETOOLS,TYPICALLYOFFEREDTHROUGHANINTEGRATEDDEVELOPMENTENVIRONMENTIDE,TOASSISTYOUINTHEASSEMBLYANDDEPLOYMENTOFYOURJAVAEEAPPLICATIONSTHEREHAVEBEENEFFORTSINTHEJAVACOMMUNITYPROCESSJCPTOSTANDARDIZEINTHISAREASEEJSR88,THEJAVAEEAPPLICATIONDEPLOYMENTAPI,BUTDEPLOYMENTINEVITABLYREQUIRESAPPLICATIONSERVERSPECIFICCONFIGURATIONTASKSFORTUNATELY,APPLICATIONSERVERSGENERALLYPROVIDEANTTASKSTOINVOKETHEIROWNDEPLOYMENTUTILITIES,ANDYOUMAYALSOUSEANTTOCREATETHEDEPLOYABLEARCHIVESTHEUSEOFANTISPREVALENTINMANYDEVELOPMENTENVIRONMENTS,ANDISNEARLYUBIQUITOUSINPRODUCTIONENVIRONMENTSINWHICHAUTOMATEDSCRIPTSAREREQUIREDTODEPLOYTHESAMEJAVAEEAPPLICATIONSTOMULTIPLEJAVAEESERVERINSTANCESMANYOFTHECUSTOMIZATIONSTEPSTHATAREDESCRIBEDINTHISCHAPTERREQUIRETHEUSEOFINTERACTIVEEDITORS,MAINLYFORUPDATINGJAVAEEGENERICANDPLATFORMSPECIFICXMLDEPLOYMENTDESCRIPTORSFORTHESETASKS,ANIDECANPROVEINVALUABLE,ANDMANYIDESPROVIDEPLATFORMSPECIFICDEPLOYMENTSUPPORTTHATGUIDESYOUINPACKAGING,CONFIGURING,ANDDEPLOYINGYOURJAVAEEAPPLICATIONSNOTETHEAPRESSWINESONLINEAPPLICATIONCOVEREDINCHAPTER7,ANDSEVERALOTHERSAMPLEAPPLICATIONSTHATACCOMPANYTHISBOOKPROVIDEDATWWWAPRESSCOM,DEMONSTRATETHEUSEOFANTSCRIPTSTOPERFORMMANYOFTHEDEPLOYMENTTASKSDESCRIBEDINTHISCHAPTEROVERVIEWOFTHEDEPLOYMENTPROCESSDEPLOYMENTISTHEPROCESSOFINSTALLINGJAVAEECOMPONENTSINANAPPLICATIONSERVERSOTHATTHEYCANBEFOUNDANDEXECUTEDWHENYOURUNYOURAPPLICATIONTHISPROCESSINVOLVESMULTIPLETASKSTHATMUSTBEPERFORMEDROUGHLYINSEQUENCETHESETASKSARESUMMARIZEDINTHEFOLLOWINGSECTIONS,ANDEACHISDESCRIBEDINGREATERDETAILANDAPPLIEDSPECIFICALLYTOEJBANDJPADEPLOYMENTLATERINTHISCHAPTERSOMESTEPSWILLONLYNEEDTOBEPERFORMEDUNDERSPECIALCIRCUMSTANCES,SOACTUALDEPLOYMENTMAYINVOLVEONLYASUBSETOFTHESETASKSTHEPROVIDERGENERALLYSPEAKING,THEPROVIDERTHEREMAYBEMANYFORAGIVENPROJECTPRODUCESTHEJAVAEEAPPLICATIONCOMPONENTSASAPRECURSORTODEPLOYMENTTHETASKSASSOCIATEDWITHTHEPROVIDER,ALONGWITHTHEFILESDELIVEREDBYTHISROLE,ARESHOWNINFIGURE111FIGURE111TASKSANDDELIVERABLESOFTHEAPPLICATIONCOMPONENTPROVIDERTHEDELIVERABLESFROMTHEPROVIDERAREAPPLICATIONCOMPONENTSANDPOSSIBLYMODULEDESCRIPTORS,EITHERASFILESONDISKORPACKAGEDINTOJAVAARCHIVEJARFILESTHEASSEMBLERTHEASSEMBLERTAKESTHEOUTPUTFROMTHEPROVIDER,ANDWITHITPERFORMSTHETASKSANDPRODUCESTHEDELIVERABLESILLUSTRATEDINFIGURE112FIGURE112DEPLOYMENTTASKSANDDELIVERABLESOFTHEAPPLICATIONASSEMBLERGROUPINGCOMPONENTSBYCONTAINERTYPETOPRODUCEJAVAEEMODULESTHEOUTPUTOFTHEPROVIDERISASETOFJAVAEECOMPONENTS,SUCHASEJBS,JPAENTITIES,JSFJAVASERVERFACESPAGES,APPLICATIONCLIENTCLASSES,ANDPOSSIBLYOTHERSTHEPROVIDERMAYALSOPRODUCENONJAVAEECOMPONENTS,LIKEORDINARYJAVACLASSESTHEASSEMBLERGROUPSTHEJAVAEECOMPONENTSTOGETHERSUCHTHATEACHGROUPCONTAINSCOMPONENTSOFONLYONEJAVAEECOMPONENTTYPEWHENEVERTHEPROVIDERHASDEFINEDAMODULELEVELDEPLOYMENTDESCRIPTORXMLFILE,THEASSEMBLERMAYFOLLOWANYDIRECTIVESINTHATFILETOCOMPOSETHEGROUPS,ORTHEASSEMBLERMAYCHOOSETOEITHERMERGEORSPLITDESCRIPTORSTOINCREASEORDECREASETHENUMBEROFJAVAEECOMPONENTSINEACHGROUPATTHEENDOFTHISPROCESS,EACHRESULTINGGROUPWILLBECOMEAJAVAEEMODULETHENONJAVAEECLASSESANDRESOURCESTHATARELEFTOVERMAYBEBUNDLEDINTOTHEJAVAEEMODULES,ORISOLATEDINTOTHEIROWNGROUPSTOBECOMESHARABLELIBRARYCOMPONENTSDEFININGMODULELEVELDEPLOYMENTDESCRIPTORSOPTIONALFOREACHJAVAEEMODULETHATISFORMED,THEASSEMBLERMAYLOCATEANDASSIGNADEPLOYMENTDESCRIPTORTOREPRESENTTHATMODULEINJAVAEE5,THISSTEPISOPTIONAL,SINCEANNOTATIONSNOWMAKEITPOSSIBLETOIDENTIFYTHEMODULETYPEBYANALYZINGITSFILECONTENTSFORINSTANCE,YOUINTHEROLEOFEITHERTHEPROVIDERORTHEASSEMBLERAREFREETODEFINEANEJBJARXMLDEPLOYMENTDESCRIPTORBUTUNLESSYOUAREOVERRIDINGINFORMATIONTHATISCAPTUREDINJAVAANNOTATIONS,ORYOUHAVECHOSENTONOTUSEANNOTATIONS,ITISNOLONGERNECESSARYINJAVAEE5,ANEJBMODULEISDEFINEDSIMPLYBYTHEPRESENCEOFACLASSINAFILEGROUPTHATISANNOTATEDSTATELESS,STATEFUL,ORMESSAGEDRIVENPACKAGINGCOMPONENTSWITHOPTIONALDESCRIPTORSINTOJARFILESINTHISSTAGE,THECOMPONENTGROUPSIDENTIFIEDINTHEFIRSTSTAGEAREPACKAGED,TOGETHERWITHTHEIRMODULELEVELDEPLOYMENTDESCRIPTORS,IFDEFINED,INTOFILESUSINGTHEJARFORMATEJBMODULESAREARCHIVEDINTOEJBJARFILESWITHAJAREXTENSION,WEBAPPLICATIONMODULESAREARCHIVEDINTOWEBARCHIVEWARFILESWITHAWAREXTENSION,APPLICATIONCLIENTSAREARCHIVEDINTOJARFILESWITHAJAREXTENSION,ANDSOONJPAPERSISTENCEUNITSMAYBEARCHIVEDINTOTHEIROWNJARFILESWITHJAREXTENSIONSORARCHIVEDDIRECTLYINTOEJBJARORWARFILESWELLCOVERTHISDETAILINTHE“ASSEMBLINGAPERSISTENCEUNIT”SECTIONLATERINTHECHAPTERINADDITION,NONJAVAEECOMPONENTS,SUCHASORDINARYJAVACLASSES,MAYBEADDEDTOTHESEJAVAEEMODULEARCHIVESORTHEASSEMBLERMAYARCHIVETHEMINTOTHEIROWNJARFILESTOBEDEPLOYEDASLIBRARYCOMPONENTSCREATINGANENTERPRISEARCHIVEEARFILEOPTIONALIFYOUASTHEASSEMBLERHAVECREATEDMULTIPLEARCHIVESTHATYOUWANTTODEPLOYTOGETHERASALOGICALGROUP,YOUWILLNEEDTOBUNDLETHESEARCHIVESTOGETHERINSIDEAWRAPPERJARFILEKNOWNASANEARFILE,WHICHUSESTHESUFFIXEARTHISEARFILEISREFERREDTOASAJAVAEEAPPLICATIONIFYOUHAVECREATEDONLYASINGLEEJBJARORWARARCHIVE,NOFURTHERPACKAGINGISREQUIREDYOUCANSKIPTHESTEPOFCREATINGAWRAPPEREARFILE,ANDDEPLOYTHEEJBJARORWARFILEASASTANDALONEMODULEANAPPLICATIONACTSASAPACKAGINGBOUNDARY,ENSURINGTHATTHEJAVAEECOMPONENTSINALLMODULESAREABLETOCOMMUNICATEWITHEACHOTHERWITHINASINGLENAMINGCONTEXTAJAVAEEAPPLICATIONDOESNOTNECESSARILYCORRESPONDTOANACTUALENDUSERAPPLICATIONITMAYBEUSEDBYMANYDIFFERENTCLIENTAPPLICATIONSBUTITALLOWSCLIENTAPPLICATIONSTOCONNECTTOTHEJAVAEEAPPLICATIONONCEANDACCESSTHEJAVAEECOMPONENTSINTHATAPPLICATIONFROMASINGLECONTEXTANEARFILEMAYCONTAINANAPPLICATIONLEVELDEPLOYMENTDESCRIPTOR,APPLICATIONXML,INITSMETAINFDIRECTORYTHISFILEISOPTIONALINJAVAEE5,SINCEITISNOWPOSSIBLETORELYONDEFAULTRULESTOPROVIDEDEFAULTNAMESANDPROPERTIESFOREACHMODULEBYDEFAULT,EACHMODULENAMEDEFAULTSTOTHESHORTNAMEOFITSARCHIVEFILE,MINUSTHEFILESUFFIXJAR,WAR,ETCDEFININGANAPPLICATIONXMLDESCRIPTORALLOWSYOUTOREFINETHEDEFAULTNAMESANDPROPERTIES,ANDTOSELECTIVELYCHOOSEWHICHMODULESINTHEEARFILETOINCLUDEINTHEAPPLICATIONFORAPARTICULARDEPLOYMENTASSEMBLERSPECIFICTASKSDEPENDINGONTHECOMPLETENESS,ANDTHECOMPLEXITY,OFTHEDEPLOYMENTDESCRIPTORSFOREACHMODULE,THEASSEMBLERMAYBEREQUIREDTOCOMPLETEORREFINESOMEOFTHEEXTERNALREFERENCESDECLAREDBYTHEPROVIDERINMANYCASES,THEMODULESARESUFFICIENTLYSELFCONTAINEDANDCOMPLETETHATTHEREISNOFURTHERWORKFORTHEASSEMBLERTOPERFORM,EVENWHENADEPLOYMENTDESCRIPTORISNOTSUPPLIEDBYTHEPROVIDERINMORECOMPLEXDEPLOYMENTSCENARIOS,WHENPROVIDERSUPPLIEDDOCUMENTATIONPOSSIBLYCOMMUNICATEDTHROUGHDESCRIPTIONPROPERTIESONEITHERTHEANNOTATIONSORINTHEDEPLOYMENTDESCRIPTORISUSED,THEASSEMBLERMAYNEEDTOCONSOLIDATESEMANTICALLYEQUIVALENTBUTDISPARATELYNAMEDRESOURCESINTOAMINIMAL,DISTINCTSETCONVERSELY,THEASSEMBLERMAYNEEDTOAVOIDRESOURCENAMECOLLISIONSBYRENAMINGRESOURCEREFERENCESTHATSHARETHESAMENAMEBUTHOLDDIFFERENTSEMANTICSFOREXAMPLE,IFTHEASSEMBLERISBUNDLINGTWOJAVAEEMODULESPRODUCEDBYDIFFERENTPROVIDERSINTOASINGLEJAVAEEAPPLICATION,BOTHPROVIDERSMAYREFERENCETHESAMELOGICALEJBBUTUSEDIFFERENTNAMES,ORREFERENCETHEMWITHTHENAMESNOTYETBOUNDITISTHERESPONSIBILITYOFTHEASSEMBLERTODETECTCASESSUCHASTHIS,USINGTHEDOCUMENTATIONPROVIDEDBYTHEPROVIDERS,ANDUPDATETHEEJBREFERENCESTOBINDTOASINGLENAMETHISNAMEMAYBECHOSENBYTHEASSEMBLERANDASSIGNEDTOTHEEJBINTHATAPPLICATIONCONTEXTANYCHANGESMADEBYTHEASSEMBLERAREAPPLIEDONLYTOTHEMODULEANDAPPLICATIONDEPLOYMENTDESCRIPTORFILES,ANDNOTTOTHEJAVASOURCETHISPROCESSWORKSBECAUSEOFTHERULESOFPRECEDENCEDICTATEDBYJAVAEETHATINTHECASEOFCONFLICTINGMETADATAPROPERTIESDEFINEDBOTHINTHEJAVAANNOTATIONSOURCEANDTHEXMLDEPLOYMENTDESCRIPTORS,THEDEPLOYMENTDESCRIPTORSPREVAILTHEASSEMBLERISABLETORESOLVEINCONSISTENCIESINTHEJAVASOURCEBYWORKINGONLYWITHTHEDEPLOYMENTDESCRIPTORFILESTHEDEPLOYERTHETASKSANDDELIVERABLESOFTHEDEPLOYERAREDEPICTEDINFIGURE113FIGURE113TASKSANDDELIVERABLESOFTHEAPPLICATIONDEPLOYERDEPLOYERSPECIFICTASKSUSINGINSTRUCTIONSFROMTHEASSEMBLERANDPROVIDERAGAIN,TYPICALLYCOMMUNICATEDTHROUGHDESCRIPTIONPROP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A持久化單元特定的部署需求。閱讀完本章之后，你應(yīng)該能很好地了解如何做到把EJB、JPA和其他應(yīng)用程序組件組織為JAVAEE模塊和庫組件。解決外部引用中的命名沖突和冗余。打包由一個或者多個JAVAEE模塊和庫組件構(gòu)成的JAVAEE應(yīng)用程序。聲明模塊和庫之間的類路徑相關(guān)性。把外部引用綁定到應(yīng)用服務(wù)器環(huán)境中的物理資源。111部署工具簡介本章提供一些示例，講解何如構(gòu)造應(yīng)用程序檔案，但是首先要有軟件工具通常通過集成開發(fā)環(huán)境（INTEGRATEDDEVELOPMENTENVIRONMENT，IDE）提供幫助你匯編和部署JAVAEE應(yīng)用程序。JAVACOMMUNITYPROCESS（JCP）曾致力于標(biāo)準(zhǔn)化這一領(lǐng)域參見JSR88，JAVAEE應(yīng)用程序部署API（JAVAEEAPPLIACTIONDEPLOYMENTAPI），但是部署工作不可避免地需要應(yīng)用服務(wù)器特定的配置任務(wù)。幸運地是，應(yīng)用服務(wù)器一般提供ANT任務(wù)調(diào)用它們自己的部署實用程序，并且你也可以使用ANT創(chuàng)建可部署的檔案。ANT的使用在很多部署環(huán)境中非常流行，并且?guī)缀踉谛枰詣踊_本（把同一個JAVAEE應(yīng)用程序部署到多個JAVAEE服務(wù)器實例）的產(chǎn)品環(huán)境中無處不在。本章中很多定制的步驟需要使用交互編輯器，主要用于更新JAVAEE通用的和平臺專用的XML部署描述文件。對于這些任務(wù)，IDE的價值無法衡量，很多IDE提供平臺特定的部署支持，引用你打包、部署和部署JAVAEE應(yīng)用程序。注釋第七章中講解的APRESS酒類在線（APRESSWINESONLINE）應(yīng)用程序，以及一些其他應(yīng)用程序是本書附帶的（可以在WWWAPRESSCOM找到），它們演示了如何使用ANT腳本執(zhí)行本章中介紹的多個部署任務(wù)。112部署過程概述部署是這樣一過程把JAVAEE組件安裝到應(yīng)用服務(wù)器中，以便當(dāng)你運行你的應(yīng)用程序時能夠找到并且執(zhí)行它們。這個過程涉及必須大致依次執(zhí)行的多個任務(wù)。下面幾節(jié)將對這些任務(wù)進(jìn)行概述，在本章后面的章節(jié)將詳細(xì)地講解它們，并將它們特別地用于EJB和JPA部署。一些步驟只在特定環(huán)境下才需要執(zhí)行，所以實際的部署可能只涉及這些任務(wù)的一個子集。1121提供者總的來說，提供者（PROVIDE）（給定工程可能有很多提供者）生成JAVAEE應(yīng)用程序組件，作為部署的前期準(zhǔn)備。和提供者相關(guān)的任務(wù)以及此角色提供的文件如圖111所示。提供者的交付是應(yīng)用程序組件和可能的模塊描述文件，要么作為磁盤上的文件，要么打包到JAR文件中。1122裝配者裝配者（ASSEMBER）采用提供者的輸出，并以此來執(zhí)行任務(wù)和生成交付，如圖112所示。1按照容器類型對組件分組以便生成JAVAEE模塊提供者的輸出是JAVAEE組件集合，比如EJB、JPA實體，JSF（JAVASERVERFACES）頁面、應(yīng)用程序客戶類，以及可能的其他。提供者也可能生成非JAVAEE組件，比如普通JAVA類。裝配者把JAVAEE組件分到一組，這樣每個組只包含一個JAVAEE組件類型。只要提供者定義了模塊級別的部署描述（XML）文件，裝配者就可以按照此文件中的指令進(jìn)行分組，裝配者也可以選擇合并或者拆描述文件，從而增加或者減少每個組內(nèi)JAVAEE組件的數(shù)量。在這個過程結(jié)束時，每個生成的組都將成為JAVAEE模塊。剩下的非JAVAEE類和資源可以捆綁JAVAEE模塊，也可以隔離到它們自己的組中，形成共享的庫組件。2定義模塊級別的部署描述文件（可選）對于形成的每個JAVAEE模塊，裝配者可以定義和分配表示此模塊的部署描述文件。在JAVAEE5中，這個步驟是可選的，因此此時注釋使得通過分析其文件內(nèi)容來標(biāo)識模塊類型成為可能。例如，你（以提供者或者裝配者的角色）可以自由的定義EJBJARXML部署描述文件，但是除非你要覆蓋JAVA注釋中所捕獲的信息，或者選擇不使用注釋，那么就沒這個必要。在JAVAEE5中，EJB模塊簡單地定義為被注釋為STATELESS、STATEFUL或者M(jìn)ESSAGEDRIVEN的文件組中的類的表現(xiàn)。3把組件（和可選的描述文件）打包為JAR文件在這個步驟中，第一個步驟所標(biāo)識的組件組（和它們的模塊級別的部署描述文件，如果定義了的話）被打包為JAR格式的文件。EJB模塊歸檔到以JAR為擴展名的EJBJAR文件中，WEB應(yīng)用程序模塊被歸檔到以WAR為擴展名的WEB檔案（WEBARCHIVE，WAR）文件中，應(yīng)用程序客戶被歸檔到以JAR為擴展名的JAR文件中，等等。JPA持久化單元可以被歸檔到它們自己的JAR文件中（以JAR為擴展名），或者直接歸檔到EJBJAR或WAR文件中。我們將在后章后面的118節(jié)中詳細(xì)介紹此內(nèi)容。此外，非JAVAEE組件（比如普通JAVA類）可以添加到這些JAVAEE模塊檔案中，或者裝配者可以把它們歸檔到它們自己的JAR文件中來作為庫組件部署。4創(chuàng)建EAR文件（可選）如果你（作為裝配者）創(chuàng)建了多個檔案，希望用一個邏輯組一起部署它們，那么你需要把這些檔案捆綁在包裝器JAR文件中，它被稱為EAR文件，以EAR為后綴，此EAR文件被引用為JAVAEE應(yīng)用程序。如果你只創(chuàng)建了一個EJBJAR或者WAR檔案，那么就不需要進(jìn)一步打包。你可以跳過創(chuàng)建包裝器EAR文件的步驟，把EJBJAR或者WAR文件作為獨立模塊部署。應(yīng)用程序作為打包邊界，確保所有模塊中的JAVAEE組件能夠在單一命名上下文相互通信。JAVAEE應(yīng)用程序并不一定對應(yīng)實際的最終用戶應(yīng)用程序（它可能被多個不同客戶應(yīng)用程序使用）但是它允許客戶應(yīng)用程序連接到JAVAEE應(yīng)用程序并且從單一上下文訪問此應(yīng)用程序中的JAVAEE組件EAR文件可以在其METAINF目錄中包含一個應(yīng)用程序級別的部署描述文件APPLICATIONXML。此文件在JAVAEE5中是可選的，因為現(xiàn)在可以依靠默認(rèn)規(guī)則提供每個模塊的默認(rèn)名稱和屬性。按照默認(rèn)，每個模塊名稱默認(rèn)為其檔案文件名減去文件名后綴（JAR、WAR等）的短名稱。定義APPLIACTIONXML描述文件允許你默認(rèn)名稱和屬性，并且選擇EAR文件中的哪些模塊包含在應(yīng)用程序的特定部署過程中。5裝配者待定任務(wù)根據(jù)每個模塊的部署描述文件的完整性和復(fù)雜性，可能需要裝備配完成或者調(diào)整提者聲明的一些外部引用。在很多情況下，模塊是充分自含和完整的，不需要裝配者進(jìn)行進(jìn)一步處理，即使是在提供者沒有提供部署描述文件的情況下。在更加復(fù)雜的部署環(huán)境中，當(dāng)使用提供者