翻译文献-ejb 3部署

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,TYPICALLYCOMMUNICATEDTHROUGHDESCRIPTIONPROPERTIESINTHEDEPLOYMENTDESCRIPTORSORSOURCEANNOTATIONSTHEDEPLOYERISREQUIREDTOBINDALLEXTERNALREFERENCESONTOCONCRETERESOURCESEJBREFERENCES,RESOURCEREFERENCES,PERSISTENCEUNITREFERENCES,ETCINTHETARGETAPPLICATIONSERVERENVIRONMENTONLYTHEDEPLOYERCANPRESUMETOKNOWABOUTTHETARGETSERVERENVIRONMENT,ANDJAVAEEHASDELIBERATELYADDEDALAYEROFINDIRECTIONTOALLRESOURCEUSAGETOALLOWTHISBINDINGTOOCCURWITHOUTAFFECTINGTHEWORKOFEITHERTHEPROVIDERORTHEASSEMBLERTHISISWHYALLRESOURCESUSEDBYTHEJAVAEECOMPONENTSAREREFERREDTOVIAINDIRECTREFERENCESASWASTHECASEWITHTHEASSEMBLER,JAVAEEPOLICYDICTATESTHATTHEDEPLOYERISALLOWEDTOMAKECHANGESONLYTOTHEXMLDEPLOYMENTDESCRIPTORFILES,ANDNOTTOANNOTATIONSINTHEJAVASOURCEINVOKINGTHEAPPLICATIONSERVERSPECIFICDEPLOYMENTTOOLFINALLY,YOURJAVAEEMODULEORYOURJAVAEEAPPLICATIONISREADYTOBESUBMITTEDTOTHEAPPLICATIONSERVERYOURAPPLICATIONSERVERWILLPROVIDEADEPLOYMENTTOOLTHATLETSYOUCOMPLETETHEDEPLOYMENTANDINSTALLTHEJAVAEECOMPONENTSINTHEAPPSERVER,READYTOBEEXECUTEDBYENDUSERAPPLICATIONSDURINGTHISSTAGE,THEDEPLOYMENTTOOLWILLVALIDATETHEMODULESBEINGSUBMITTEDFORINTERNALINTEGRITY,ANDENSURETHATALLRESOURCESCANBEBOUNDTOACTUALOBJECTSTHATRESIDEINTHEAPPLICATIONSERVERENVIRONMENTIFANYREQUIREDRESOURCESCANNOTBELOCATEDATDEPLOYTIME,ORIFREFERENCEDLIBRARYCOMPONENTSARENOTFOUND,THEDEPLOYMENTWILLFAILSUMMARYOFOVERVIEWJAVAEEDEPLOYMENTLETSYOUDEPLOYINDIVIDUALMODULES,LIBRARYCOMPONENTS,ORCOMPLETEAPPLICATIONSINMANYCASES,ADEPLOYMENTMAYSIMPLYINVOLVEPACKAGINGTHECOMPILEDSOURCE,TOGETHERWITHTHEDESCRIPTORSAPERSISTENCEXMLFILEISMANDATORYFORPERSISTENCEUNITS,BUTANEJBJARXMLFILEISOPTIONALFOREJBJARFILES,ANDSUBMITTINGTOADEPLOYMENTTOOLWHENASSEMBLINGAPPLICATIONSFROMMULTIPLEMODULESTHATMAYHAVEBEENBUILTBYDIFFERENTCOMPONENTPROVIDERSANDMAYBEOFDIFFERINGVERSIONS,THEASSEMBLERROLETAKESONGREATERIMPORTANCEJAVAEEDEPLOYMENTINFRASTRUCTURENOWTHATWEHAVESUMMARIZEDTHEDEPLOYMENTPROCESS,LETUSEXPLORESOMEAREASOFTHEJAVAEEINFRASTRUCTURETHATARECENTRALTODEPLOYMENTANUNDERSTANDINGOFTHISTOPICISUSEFULWHENITCOMESTIMETOMAKEYOUROWNDECISIONSABOUTHOWTOPACKAGEYOURCODEINTOMODULES,ANDRESOLVEANDBINDEXTERNALREFERENCESTHEJAVAEESERVERTHEJAVAEESERVERISTHEPROGRAMRUNNINGINSIDEYOURAPPLICATIONSERVERTHATPROVIDESENTERPRISESERVICESTOYOURJAVAEECOMPONENTSWHENTHEYARERUNTHEJAVAEESERVERISALSORESPONSIBLEFORHANDLINGDEPLOYMENTREQUESTSANDREDIRECTINGTHEMTOTHEJAVAEECONTAINERSTHATITHOSTSTHEJAVAEESPECDEFINESTHELISTOFCORESERVICESTHATMUSTBESUPPORTEDBYAJAVAEESERVERTHESEINCLUDEMESSAGING,DATABASE,SECURITY,TRANSACTION,PERSISTENCE,ANDMANYOTHERSERVICESTHEJAVAEESERVERMAYALSOBEEXTENDEDTOPROVIDEADDITIONALSERVICES,ORALTERNATIVEIMPLEMENTATIONSOFEXISTINGSERVICES,BEYONDTHOSEMANDATEDBYTHESPECJAVAEEDEFINESHOWASERVERMAYBEEXTENDEDTOPROVIDEITSCONTAINERSWITHACCESSTOREMOTEANDEXTERNALSERVICES,BYADAPTINGTHEMINTOTHEJAVAEEENVIRONMENTUSINGRESOURCEADAPTERSTHROUGHTHEJAVAEECONNECTORAPITHEJAVAEECONTAINERSTHEPRIMARYPURPOSEOFTHEJAVAEESERVERISTOSUPPORTJAVAEECONTAINERS,WHICHPROVIDETHEENVIRONMENTSINWHICHJAVAEECOMPONENTSARERUNJAVAEE5SPECIFIESSUPPORTFORFOURJAVAEECONTAINERSEJB,WEB,APPLICATIONCLIENT,ANDAPPLETWHILETHEEJBANDWEBCONTAINERSEXECUTEINTHEAPPLICATIONSERVERRUNNINGINTHEMIDDLETIER,THEAPPLICATIONCLIENTCONTAINERTYPICALLYEXECUTESINAJAVASEENVIRONMENTONTHECLIENTTIER,ANDTHEAPPLETCONTAINERTYPICALLYRUNSINSIDEAWEBBROWSERNONETHELESS,THEYALLRELYONTHEIRUNDERLYINGJAVAEESERVERFORTHEMANYENTERPRISESERVICESTHATTHEYINTURNPROVIDE,THROUGHAPIS,TOTHECOMPONENTSTHATEXECUTEINSIDETHEIRCONTAINERENVIRONMENTFORINSTANCE,AJAVAEESERVERPROVIDESNATIVEMESSAGINGSERVICESTOAJAVAEECONTAINER,ANDTHECONTAINEREXPOSESMESSAGINGSERVICESTOITSCOMPONENTSTHROUGHTHEJMSJAVAMESSAGESERVICEAPISIMILARLY,THECONTAINEREXPOSESDATABASESERVICESTHROUGHJAVADATABASECONNECTIVITYJDBC,TRANSACTIONSERVICESTHROUGHJAVATRANSACTIONAPIJTA,ANDSOONTHEJAVAEECONTAINERSALSOINTERPOSEONALLCOMMUNICATIONBETWEENJAVAEEAPPLICATIONCOMPONENTSEXECUTINGINJAVAEECONTAINERS,TOPROVIDECOMPONENTANDRESOURCEINJECTIONINADDITIONTOTHEMANYBUILTINSERVICESOFFEREDTOJAVAEECOMPONENTSBYTHEJAVAEECONTAINERS,JAVAEEALLOWSFORTHEINTEGRATIONOFTHIRDPARTYSERVICESTHROUGHRESOURCEADAPTERSANDTHECONNECTORAPITHATAREEXPOSEDTOJAVAEECOMPONENTSTHROUGHTHEIRCONTAINERSUSINGTHEJAVAEESERVICEPROVIDERINTERFACESPI中文翻译EJB3部署到目前为止，本书都在讲解如果构造EJB、JPA和它们的客户，用于利用EJB容器提供的企业服务。用JAVAEE的说法，这些任务被归入应用程序组件提供者（APPLICATIONCOMPONENTPROVIDER）的角色，它在这里简称为提供者（PROVIDER）。本章讲解的主题围绕把组件打包为模块和库组件，把JAVAEE组件中声明的外部引用绑定到服务器环境中的实际资源，并把它全部发送给应用服务器，以便应用程序在运行时执行组件。这些责任由应用程序装配者（APPLICATIONASSEMBLER，简称装配者）和应用程序部署者（APPLICATIONDEPLOYER,简称部署者）的JAVAEE角色承担。虽然在实际中经常由单一个体扮演一个或者多个这些角色，或者由很多人扮演其中的任何一个角色，但是出于讲解这些主题的目的，我们将把部署任务划分为若干对应这些指定角色的阶段。我们将重点讲解EJB和JPA实体组件，但是也会介绍和部署有关的其它JAVAEE模块类型WEB应用程序模块、应用程序客户和资源适配器。我们还会介绍JAVAEE服务器和它支持的4种JAVAEE容器之间的关系，并且讲解JAVAEE服务器提供的一些服务。我们在部署任务的简要概述中将介绍大部分部署术语，然后，介绍支持部署的JAVAEE基础结构组件JAVAEE服务器和容器。我们讲解JAVAEE模块类型的区别和她它们如何整合在一起，以及如何指定定义每个模块的部署描述文件元数据文件。关于库组件的一节讲解如何声明JAVAEE模块和库组件之间的类路径相关性。然后更加详细地分析装配者（ASSEMBER）和部署者（DEPLOYER）角色，最后总结EJB模块和JPA持久化单元特定的部署需求。阅读完本章之后，你应该能很好地了解如何做到把EJB、JPA和其他应用程序组件组织为JAVAEE模块和库组件。解决外部引用中的命名冲突和冗余。打包由一个或者多个JAVAEE模块和库组件构成的JAVAEE应用程序。声明模块和库之间的类路径相关性。把外部引用绑定到应用服务器环境中的物理资源。111部署工具简介本章提供一些示例，讲解何如构造应用程序档案，但是首先要有软件工具通常通过集成开发环境（INTEGRATEDDEVELOPMENTENVIRONMENT，IDE）提供帮助你汇编和部署JAVAEE应用程序。JAVACOMMUNITYPROCESS（JCP）曾致力于标准化这一领域参见JSR88，JAVAEE应用程序部署API（JAVAEEAPPLIACTIONDEPLOYMENTAPI），但是部署工作不可避免地需要应用服务器特定的配置任务。幸运地是，应用服务器一般提供ANT任务调用它们自己的部署实用程序，并且你也可以使用ANT创建可部署的档案。ANT的使用在很多部署环境中非常流行，并且几乎在需要自动化脚本（把同一个JAVAEE应用程序部署到多个JAVAEE服务器实例）的产品环境中无处不在。本章中很多定制的步骤需要使用交互编辑器，主要用于更新JAVAEE通用的和平台专用的XML部署描述文件。对于这些任务，IDE的价值无法衡量，很多IDE提供平台特定的部署支持，引用你打包、部署和部署JAVAEE应用程序。注释第七章中讲解的APRESS酒类在线（APRESSWINESONLINE）应用程序，以及一些其他应用程序是本书附带的（可以在WWWAPRESSCOM找到），它们演示了如何使用ANT脚本执行本章中介绍的多个部署任务。112部署过程概述部署是这样一过程把JAVAEE组件安装到应用服务器中，以便当你运行你的应用程序时能够找到并且执行它们。这个过程涉及必须大致依次执行的多个任务。下面几节将对这些任务进行概述，在本章后面的章节将详细地讲解它们，并将它们特别地用于EJB和JPA部署。一些步骤只在特定环境下才需要执行，所以实际的部署可能只涉及这些任务的一个子集。1121提供者总的来说，提供者（PROVIDE）（给定工程可能有很多提供者）生成JAVAEE应用程序组件，作为部署的前期准备。和提供者相关的任务以及此角色提供的文件如图111所示。提供者的交付是应用程序组件和可能的模块描述文件，要么作为磁盘上的文件，要么打包到JAR文件中。1122装配者装配者（ASSEMBER）采用提供者的输出，并以此来执行任务和生成交付，如图112所示。1按照容器类型对组件分组以便生成JAVAEE模块提供者的输出是JAVAEE组件集合，比如EJB、JPA实体，JSF（JAVASERVERFACES）页面、应用程序客户类，以及可能的其他。提供者也可能生成非JAVAEE组件，比如普通JAVA类。装配者把JAVAEE组件分到一组，这样每个组只包含一个JAVAEE组件类型。只要提供者定义了模块级别的部署描述（XML）文件，装配者就可以按照此文件中的指令进行分组，装配者也可以选择合并或者拆描述文件，从而增加或者减少每个组内JAVAEE组件的数量。在这个过程结束时，每个生成的组都将成为JAVAEE模块。剩下的非JAVAEE类和资源可以捆绑JAVAEE模块，也可以隔离到它们自己的组中，形成共享的库组件。2定义模块级别的部署描述文件（可选）对于形成的每个JAVAEE模块，装配者可以定义和分配表示此模块的部署描述文件。在JAVAEE5中，这个步骤是可选的，因此此时注释使得通过分析其文件内容来标识模块类型成为可能。例如，你（以提供者或者装配者的角色）可以自由的定义EJBJARXML部署描述文件，但是除非你要覆盖JAVA注释中所捕获的信息，或者选择不使用注释，那么就没这个必要。在JAVAEE5中，EJB模块简单地定义为被注释为STATELESS、STATEFUL或者MESSAGEDRIVEN的文件组中的类的表现。3把组件（和可选的描述文件）打包为JAR文件在这个步骤中，第一个步骤所标识的组件组（和它们的模块级别的部署描述文件，如果定义了的话）被打包为JAR格式的文件。EJB模块归档到以JAR为扩展名的EJBJAR文件中，WEB应用程序模块被归档到以WAR为扩展名的WEB档案（WEBARCHIVE，WAR）文件中，应用程序客户被归档到以JAR为扩展名的JAR文件中，等等。JPA持久化单元可以被归档到它们自己的JAR文件中（以JAR为扩展名），或者直接归档到EJBJAR或WAR文件中。我们将在后章后面的118节中详细介绍此内容。此外，非JAVAEE组件（比如普通JAVA类）可以添加到这些JAVAEE模块档案中，或者装配者可以把它们归档到它们自己的JAR文件中来作为库组件部署。4创建EAR文件（可选）如果你（作为装配者）创建了多个档案，希望用一个逻辑组一起部署它们，那么你需要把这些档案捆绑在包装器JAR文件中，它被称为EAR文件，以EAR为后缀，此EAR文件被引用为JAVAEE应用程序。如果你只创建了一个EJBJAR或者WAR档案，那么就不需要进一步打包。你可以跳过创建包装器EAR文件的步骤，把EJBJAR或者WAR文件作为独立模块部署。应用程序作为打包边界，确保所有模块中的JAVAEE组件能够在单一命名上下文相互通信。JAVAEE应用程序并不一定对应实际的最终用户应用程序（它可能被多个不同客户应用程序使用）但是它允许客户应用程序连接到JAVAEE应用程序并且从单一上下文访问此应用程序中的JAVAEE组件EAR文件可以在其METAINF目录中包含一个应用程序级别的部署描述文件APPLICATIONXML。此文件在JAVAEE5中是可选的，因为现在可以依靠默认规则提供每个模块的默认名称和属性。按照默认，每个模块名称默认为其档案文件名减去文件名后缀（JAR、WAR等）的短名称。定义APPLIACTIONXML描述文件允许你默认名称和属性，并且选择EAR文件中的哪些模块包含在应用程序的特定部署过程中。5装配者待定任务根据每个模块的部署描述文件的完整性和复杂性，可能需要装备配完成或者调整提者声明的一些外部引用。在很多情况下，模块是充分自含和完整的，不需要装配者进行进一步处理，即使是在提供者没有提供部署描述文件的情况下。在更加复杂的部署环境中，当使用提供者