翻译文献-jsp.7.4验证

外文原文JSP74VALIDATIONTHEREAREANUMBEROFREASONSWHYTHESTRUCTUREOFAJSPPAGESHOULDCONFORMTOSOMEVALIDATIONRULESREQUESTTIMESEMANTICSEGASUBELEMENTMAYREQUIRETHEINFORMATIONFROMSOMEENCLOSINGELEMENTATREQUESTTIMEAUTHORINGTOOLSUPPORTEGATOOLMAYREQUIREANORDERINGINTHEACTIONSMETHODOLOGICALCONSTRAINTSEGADEVELOPMENTGROUPMAYWANTTOCONSTRAINTHEWAYSOMEFEATURESAREUSEDVALIDATIONCANBEDONEEITHERATTRANSLATIONTIMEORATREQUESTTIMEINGENERALTRANSLATIONTIMEVALIDATIONPROVIDESABETTERUSEREXPERIENCE,ANDTHEJSP20SPECIFICATIONPROVIDESAVERYFLEXIBLETRANSLATIONTIMEVALIDATIONMECHANISMJSP741TRANSLATIONTIMEMECHANISMSSOMETRANSLATIONTIMEVALIDATIONISREPRESENTEDINTHETAGLIBRARYDESCRIPTORINSOMECASESATAGEXTRAINFOCLASSNEEDSTOBEPROVIDEDTOSUPPLEMENTTHISINFORMATIONJSP7411ATTRIBUTEINFORMATIONTHETAGLIBRARYDESCRIPTORCONTAINSTHEBASICSYNTACTICINFORMATIONINPARTICULAR,THEATTRIBUTESAREDESCRIBEDINCLUDINGTHEIRNAME,WHETHERTHEYAREOPTIONALORMANDATORY,ANDWHETHERTHEYACCEPTREQUESTTIMEEXPRESSIONSADDITIONALLYTHEBODYCONTENTELEMENTCANBEUSEDTOINDICATETHATANACTIONMUSTBEEMPTYALLCONSTRAINTSDESCRIBEDINTHETLDMUSTBEENFORCEDATAGLIBRARYAUTHORCANASSUMETHATTHETAGHANDLERINSTANCECORRESPONDSTOANACTIONTHATSATISFIESALLCONSTRAINTSINDICATEDINTHETLDJSP7412VALIDATORCLASSESATAGLIBRARYVALIDATORCLASSMAYBELISTEDINTHETLDFORATAGLIBRARYTOREQUESTTHATAJSPPAGEBEVALIDATEDTHEXMLVIEWOFAJSPPAGEISEXPOSEDTHROUGHAPAGEDATACLASS,ANDTHEVALIDATORCLASSCANDOANYCHECKSTHETAGLIBRARYAUTHORMAYHAVEFOUNDAPPROPRIATETHEJSPCONTAINERMUSTUNIQUELYIDENTIFYALLXMLELEMENTSINTHEXMLVIEWOFAJSPPAGETHROUGHAJSPIDATTRIBUTETHISATTRIBUTECANUSEDTOPROVIDEBETTERINFORMATIONONTHELOCATIONOFANERRORTHEVALIDATORCLASSMECHANISMISNEWASOFTHEJSP12SPECIFICATIONATAGLIBRARYVALIDATORCANBEPASSEDSOMEINITIALIZATIONPARAMETERSINTHETLDTHISEASESTHEREUSEOFVALIDATORCLASSESWEEXPECTTHATVALIDATORCLASSESWILLBEWRITTENBASEDONDIFFERENTXMLSCHEMAMECHANISMSDTDS,XSCHEMA,RELAXX,OTHERSSTANDARDVALIDATORCLASSESMAYBEINCORPORATEDINTOALATERVERSIONOFTHEJSPSPECIFICATIONIFACLEARSCHEMASTANDARDAPPEARSATSOMEPOINTJSP7413TAGEXTRAINFOCLASSVALIDATIONTAGEXTRAINFOADDITIONALTRANSLATIONTIMEVALIDATIONCANBEDONEUSINGTHEVALIDATEMETHODINTHETAGEXTRAINFOCLASSTHEVALIDATEMETHODISINVOKEDATTRANSLATIONTIMEANDISPASSEDATAGDATAINSTANCEASITSARGUMENTASOFJSP20,THEDEFAULTBEHAVIOROFVALIDATEISTOCALLTHEISVALIDMETHODTHEISVALIDMECHANISMWASTHEORIGINALVALIDATIONMECHANISMINTRODUCEDINJSP11WITHTHERESTOFTHETAGEXTENSIONMACHINERYTAGLIBRARIESTHATAREDESIGNEDTORUNINJSP12CONTAINERSORHIGHERSHOULDUSETHEVALIDATORCLASSMECHANISMTAGLIBRARIESTHATAREDESIGNEDTORUNINJSP20CONTAINERSORHIGHERTHATWISHTOUSETHETAGEXTRAINFOVALIDATIONMECHANISMAREENCOURAGEDTOIMPLEMENTTHEVALIDATEMETHODINFAVOROFTHEISVALIDMETHODDUETOTHEABILITYTOIMPLEMENTINGBOTHISNOTRECOMMENDEDJSP742REQUESTTIMEERRORSINSOMECASES,ADDITIONALREQUESTTIMEVALIDATIONWILLBEDONEDYNAMICALLYWITHINTHEMETHODSINTHETAGHANDLERIFANERRORISDISCOVERED,ANINSTANCEOFJSPEXCEPTIONCANBETHROWNIFUNCAUGHT,THISOBJECTWILLINVOKETHEERRORPAGEMECHANISMOFTHEJSPSPECIFICATIONJSP75CONVENTIONSANDOTHERISSUESTHISSECTIONISNOTNORMATIVE,ALTHOUGHITREFLECTSGOODDESIGNPRACTICESJSP751HOWTODEFINENEWIMPLICITOBJECTSWEADVOCATETHEFOLLOWINGSTYLEFORTHEINTRODUCTIONOFIMPLICITOBJECTSDEFINEATAGLIBRARYADDANACTIONCALLEDDEFINEOBJECTSTODEFINETHEDESIREDOBJECTSTHEJSPPAGECANMAKETHESEOBJECTSAVAILABLEASFOLLOWSSTARTUSINGTHEOBJECTSTHISAPPROACHHASTHEADVANTAGEOFREQUIRINGNONEWMACHINERYANDOFMAKINGVERYEXPLICITTHEDEPENDENCYINSOMECASESTHEREMAYBEANIMPLEMENTATIONDEPENDENCYINMAKINGTHESEOBJECTSAVAILABLEFOREXAMPLE,THEYMAYBEPROVIDINGACCESSTOSOMEFUNCTIONALITYTHATEXISTSONLYINAPARTICULARIMPLEMENTATIONTHISCANBEDONEBYHAVINGTHETAGEXTENSIONCLASSTESTATRUNTIMEFORTHEEXISTENCEOFSOMEIMPLEMENTATIONDEPENDENTFEATUREANDRAISEARUNTIMEERRORTHIS,OFCOURSE,MAKESTHEPAGENOTJ2EECOMPLIANTTHISMECHANISM,TOGETHERWITHTHEACCESSTOMETADATAINFORMATIONALLOWSFORVENDORSTOINNOVATEWITHINTHESTANDARDNOTEIFAFEATUREISADDEDTOAJSPSPECIFICATION,ANDAVENDORALSOPROVIDESTHATFEATURETHROUGHITSVENDORSPECIFICMECHANISM,THESTANDARDMECHANISM,ASINDICATEDINTHEJSPSPECIFICATIONWILL“WIN”THISMEANSTHATVENDORSPECOFICMECHANISMSCANSLOWLYMIGRATEINTOTHESPECIFICATIONASTHEYPROVETHEIRUSEFULNESSJSP752ACCESSTOVENDORSPECIFICINFORMATIONIFAVENDORWANTSTOASSOCIATESOMEINFORMATIONTHATISNOTDESCRIBEDINTHECURRENTVERSIONOFTHETLDWITHSOMETAGLIBRARY,ITCANDOSOBYINSERTINGTHEINFORMATIONINADOCUMENTITCONTROLS,INSERTINGTHEDOCUMENTINTHEWEBINFPORTIONOFTHEWEBAPPLICATIONWHERETHETAGLIBRARYRESIDES,ANDUSINGTHESTANDARDSERVLET24MECHANISMSTOACCESSTHATINFORMATIONJSP753CUSTOMIZINGATAGLIBRARYATAGLIBRARYCANBECUSTOMIZEDATASSEMBLYANDDEPLOYMENTTIMEFOREXAMPLE,ATAGLIBRARYTHATPROVIDESACCESSTODATABASESMAYBECUSTOMIZEDWITHLOGINANDPASSWORDINFORMATIONTHEREISNOCONVENIENTPLACEINWEBXMLINTHESERVLET24SPECFORCUSTOMIZATIONINFORMATIONASTANDARDIZEDMECHANISMISPROBABLYGOINGTOBEPARTOFAFORTHCOMINGJSPSPECIFICATION,BUTINTHEMEANTIMETHESUGGESTIONISTHATATAGLIBRARYAUTHORPLACETHISINFORMATIONINAWELLKNOWNLOCATIONATSOMERESOURCEINTHEWEBINF/PORTIONOFTHEWEBAPPLICATIONANDACCESSITVIATHEGETRESOURCECALLONTHESERVLETCONTEXTCHAPTERJSP8TAGFILESTHISCHAPTERDESCRIBESTHEDETAILSOFTAGFILES,AJSP20FACILITYTHATALLOWSPAGEAUTHORSTOAUTHORTAGEXTENSIONSUSINGONLYJSPSYNTAXINTHEPAST,THEABILITYTOENCAPSULATEPRESENTATIONLOGICINTOREUSABLE,FULLFEATUREDTAGLIBRARIESWASONLYAVAILABLETODEVELOPERSTHATHADAREASONABLEAMOUNTOFJAVAEXPERIENCETAGFILESBRINGTHEPOWEROFREUSETOTHEBASICPAGEAUTHOR,WHOARENOTREQUIREDTOKNOWJAVAWHENUSEDTOGETHERWITHJSPFRAGMENTSANDSIMPLETAGHANDLERS,THESECONCEPTSHAVETHEABILITYTOSIMPLIFYJSPDEVELOPMENTSUBSTANTIALLY,EVENFORDEVELOPERSWHODOKNOWJAVAJSP81OVERVIEWASOFJSPVERSION20,THEJSPCOMPILERISREQUIREDTORECOGNIZETAGFILESATAGFILEISASOURCEFILETHATPROVIDESAWAYFORAPAGEAUTHORTOABSTRACTASEGMENTOFJSPCODEANDMAKEITREUSABLEVIAACUSTOMACTIONTAGFILESALLOWAJSPPAGEAUTHORTOCREATETAGLIBRARIESUSINGJSPSYNTAXTHISMEANSTHATPAGEAUTHORSNOLONGERNEEDTOKNOWJAVAORASKSOMEONEWHOKNOWSJAVATOWRITEATAGEXTENSIONEVENFORPAGEAUTHORSORTAGLIBRARYDEVELOPERSWHOKNOWJAVA,WRITINGTAGFILESISMORECONVENIENTWHENDEVELOPINGTAGSTHATPRIMARILYOUTPUTTEMPLATETEXTTHEREQUIREDFILEEXTENSIONFORATAGFILEARETAGORTAGXASISTHECASEWITHJSPFILES,THEACTUALTAGMAYBECOMPOSEDOFATOPFILETHATINCLUDESOTHERFILESTHATCONTAINEITHERACOMPLETETAGORASEGMENTOFATAGFILEJUSTASTHERECOMMENDEDEXTENSIONFORASEGMENTOFAJSPFILEISJSPF,THERECOMMENDEDEXTENSIONFORASEGMENTOFATAGFILEISTAGFJSP82SYNTAXOFTAGFILESTHESYNTAXOFATAGFILEISSIMILARTOTHATOFAJSPPAGE,WITHTHEFOLLOWINGEXCEPTIONSDIRECTIVESSOMEDIRECTIVESARENOTAVAILABLEORHAVELIMITEDAVAILABILITY,ANDSOMETAGFILESPECIFICDIRECTIVESAREAVAILABLESEESECTIONJSP85,”TAGFILEDIRECTIVES”FORADISCUSSIONONTAGFILEDIRECTVESTHEANDSTANDARDACTIONSCANONLYBEUSEDINTAGFILESTHEEBNFGRAMMARINSECTIONJSP1310,”JSPSYNTAXGRAMMAR”DESCRIBESTHESYNTAXOFTAGFILESTHEROOTPRODUCTIONFORATAGFILESISJSPTAGDEFSEESECTIONJSP86FORDETAILSONTAGFILESINXMLSYNTAXJSP83SEMANTICSOFTAGFILESFOREACHTAGFILEINTHEWEBAPPLICATION,ATAGHANDLERISMADEAVAILABLETOJSPPAGESANDOTHERTAGFILESTHESPECIFICSOFHOWTHISISDONEARELEFTUPTOTHECONTAINERIMPLEMENTATIONFOREXAMPLE,SOMECONTAINERSMAYCHOOSETOCOMPILETAGFILESINTOJAVATAGHANDLERS,WHEREASOTHERSMAYDECIDETOINTERPRETTHETAGHANDLERSHOWEVERTHECONTAINERCHOOSESTOPREPARETHETAGHANDLER,THEFOLLOWINGCONDITIONMUSTHOLDTRUEFORALLTAGHANDLERSDEFINEDASTAGFILESTHETAGFILEIMPLEMENTATIONMUSTKEEPACOPYOFTHEJSPCONTEXTINSTANCEPASSEDTOITBYTHEINVOKINGPAGEVIATHESETJSPCONTEXTMETHODTHISISCALLEDTHEINVOKINGJSPCONTEXTTHETAGFILEIMPLEMENTATIONMUSTCREATEANDMAINTAINASECONDINSTANCEOFJSPCONTEXTCALLEDAJSPCONTEXTWRAPPERIFTHEINVOKINGJSPCONTEXTISANINSTANCEOFPAGECONTEXT,THEJSPCONTEXTWRAPPERMUSTALSOBEANINSTANCEOFPAGECONTEXTTHISWRAPPERMUSTBERETURNEDWHENGETJSPCONTEXTISCALLEDFOREACHINVOCATIONTOTHETAG,THEJSPCONTEXTWRAPPERMUSTPRESENTACLEANPAGESCOPEMUSTBEIDENTICALTOTHOSEINTHEINVOKINGJSPCONTEXTANDMUSTBEMODIFIEDACCORDINGLYWHENUPDATESAREMADETOTHOSESCOPESINTHEJSPCONTEXTWRAPPERANYMODIFICATIONSTOTHEPAGESCOPE,HOWEVER,MUSTNOTAFFECTTHEINVOKINGJSPCONTEXTFOREACHATTRIBUTEDECLAREDANDSPECIFIED,APAGESCOPEDVARIABLEMUSTBECREATEDINTHEPAGESCOPEOFTHEJSPCONTEXTWRAPPERTHENAMEOFTHEVARIABLEMUSTBETHESAMEASTHEDECLAREDATTRIBUTENAMETHEVALUEOFTHEVARIABLEMUSTBETHEVALUEOFTHEATTRIBUTEPASSEDINDURINGINVOCATIONFOREACHATTRIBUTEDECLAREDASOPTIONALANDNOTSPECIFIED,NOPAGESCOPEDVARIABLEISCREATEDIFTHETAGACCEPTSDYNAMICATTRIBUTES,THENTHENAMESANDVALUESOFTHOSEDYNAMICATTRIBUTESMUSTBEEXPOSEDTOTHETAGFILEASSPECIFIEDINTABLEJSP82FORALLINTENTSANDPURPOSESOTHERTHANFORSYNCHRONIZINGTHEAT_BEGIN,NESTED,ANDAT_ENDSCRIPTINGVARIABLES,THEEFFECTIVEJSPCONTEXTFORTHETAGFILEISTHEJSPCONTEXTWRAPPERFOREXAMPLE,THEJSPCONTEXTSCRIPTINGVARIABLEMUSTPOINTTOTHEJSPCONTEXTWRAPPERINSTEADOFTHEINVOKINGJSPCONTEXTTHETAGHANDLERMUSTBEHAVEASTHOUGHATAGLIBRARYDESCRIPTORENTRYWASDEFINEDFORIT,INACCORDANCEWITHTHETAG,ATTRIBUTE,ANDVARIABLEDIRECTIVESTHATAPPEARINTHETAGFILETRANSLATIONUNITITISLEGALFORATAGFILETOFORWARDTOAPAGEVIATHESTANDARDACTIONJUSTASFORJSPPAGES,THEFORWARDISHANDLEDTHROUGHTHEREQUESTDISPATCHERUPONRETURNFROMTHEREQUESTDISPATCHERFORWARDMETHOD,THEGENERATEDTAGHANDLERMUSTSTOPPROCESSINGOFTHETAGFILEANDTHROWJAVAXSERVLETJSPSKIPPAGEEXCEPTIONSIMILARLY,IFATAGFILEINVOKESACLASSICTAGHANDLERWHICHRETURNSSKIP_PAGEFROMTHEDOENDTAGMETHOD,ORIFITINVOKESASIMPLETAGHANDLERWHICHTHROWSSKIPPAGEEXCEPTIONINTHEDOTAGMETHOD,THEGENERATEDTAGHANDLERMUSTTERMINATEANDSKIPPAGEEXCEPTIONMUSTBETHROWNINEITHEROFTHESETWOCASES,THEDOCATCHANDDOFINALLYMETHODSMUSTBECALLEDONENCLOSINGTAGSTHATIMPLEMENTTHETRYCATCHFINALLYINTERFACEBEFORERETURNINGTHEDOENDTAGMETHODSOFENCLOSINGCLASSICTAGSMUSTNOTBECALLEDCARESHOULDBETAKENWHENINVOKINGACLASSICTAGHANDLERFROMATAGFILEINGENERAL,SIMPLETAGEXTENSIONSCANBEUSEDINENVIRONMENTSOTHERTHANSERLETENVIRONMENTSHOWEVER,BECAUSETHETAGINTERFACERELIESONPAGECONTEXT,WHICHINTURNASSUMESASERVLETENVIRONMENT,USINGCLASSICTAGHANDLERSINDIRECTLYBINDSTHEUSEOFTHETAGFILETOSERLETENVIRONMRNTSNONETHELESS,THEJSPCONTAINERMUSTALLOWSUCHANINVOCATIONTOOCCURWHENATAGFILEATTEMPTSTOINVOKEACLASSICTAGHANDLERIEONETHATIMPLEMENTSTHETAGINTERFACE,ITMUSTCASTTHEJSPCONTEXTPASSEDTOTHESIMPLETAGINTOAPAGECONTEXTINTHEEVENTTHATTHECLASSCASTFAILS,THEINVOCATIONOFTHEECLASSICTAGFAILS,ANDAJSPEXCEPTIONMUSTBETHROWNJSP84PACKAGINGTAGFILESONEOFTHEGOALSOFTAGFILESASATECHNOLOGYISTOMAKEITASEASYTOWRITEATAGHANDLERASITISTOWRITEAJSPTRADITIONALLY,WRITINGTAGHANDLERHASBEENATEDIOUSTASK,WITHALO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些只存在于某一特定的执行的功能。由标签扩展类测试在运行时间上存在某些执行依赖特征及提出一个运行时间错误这是可以做到的（当然，这使网页的J2EE兼容）。这个机制，加上有权使用元始据信息允许提供给厂商，使厂商的创新符合标准。注释如果一个特点被增加了一个JSP的规范，并且厂商还提供了通过其供应商的具体运作机制的功能，标准的机制也显示出JSP的规范将“胜利“。这意味着厂商规格机制可以慢慢迁移到规范的，因为它们证明了其有效性。JSP752获得供应商的具体信息如果供应商联合一些资料，这没有被描述在目前版本的TLD的一些标签库，它可以这样做通过插上的一份它控制的资料文件，在在标签库居住的网站应用的WEBINF部分插入该文件，并使用标准的SERVLET24机制，以获得这方面的资料。JSP753定制标签库一个标签库可以在装配和部署时间进行定制。例如，一个标签库，可提供存取至数据库，可定制的登录名和密码信息。在SERVLET的24规格中为用户化信息的WEBXML中有没有方便的地方。一个规范的机制可能是一个即将到来的JSP规范的一部分，但在这段期间的建议是一个标签库作者把这个信息放置在一个中所周知的地点在一些资源在WEBINF/WEB应用的一部分和获得它通过GETRESOURCE号召SERVLETCONTEXT中。CHAPTERJSP8标签档案这一章描述了标签档案的细节，一个JSP的20设施，承认网页作者对作者标签延期只使用JSP的语法。在过去，概括陈述逻辑的可重新使用的能力，功能齐全的标签库只是提供给开发人员进行了合理数量的JAVA经验。标签档案，把重用的能力带给现有的基本页作者，他们不需要知道JAVA语言。当连同JSP的碎片和简单的标签处理使用时，这些观念有能力简化JSP大幅度开发，甚至使那些知道JAVA语言的开发者。JSP81总的看法截至JSP的20版本，JSP的编译器必须承认标签档案。标签文件是一个源文件，提它为一页作者提供了JSP代码的摘要部分的方法，并使之通过一个可以再用的定制的行动。标签文件允许JSP页面作者使用JSP语法创造标签库。这意味着页面作者不再需要知道JAVA或去问谁知道怎样用JAVA写标签扩展名。即使是页面作者或知道JAVA的标签库的开发者，当发展的标签主要输出模板文本时，写标签档案也会更方便。所需文件扩展为一个标签档案是TAG或者TAGX。如本例用JSP档案，但实际标签，可组成一个最高档案，其中包括其它文件，它们中包含或一个完整的标签或部分标签档案。正如一个JSP的文件被建议延长为一个部分是JSPF，建议延长为一个部分的标签档案是TAGF。JSP82标签文件的语法一个标签文件的语法类似一个JSP页面，符合下列情况除外指令一些指令，不具备或只具备有限的可用性，并为一些标签文件的具体指示是可利用的。见第JSP85，“标记的文件指示，“来直接讨论标签档案。和标准行动只可能用在标签档案上。在JSP1310节中的EBNF语法，“JSP语法文法”叙述了标记档案的语法。生产赞助的标签档案是JSPTAGDEF。详情见标签档案的XML语法中的JSP86。JSP83标签档案的语义学对于每个标签文件中的WEB应用，标签处理器使JSP页面和其他标签档案可利用。如何这么做的具体情况被放在容器实施。举例来说，有些容器可以选择编译标签档案转换成JAVA的标签处理，而其他的可能决定解释标签处理。但是容器选择编写标签处理程序，下列条件必须适用于所有的标签处理程序定义为标签档案标签文件的执行必须保留一份该JSPCONTEXT的实例通过给它援引页面经SETJSPCONTEXT方法。这就是所谓援引JSP的背景。标签文件的执行必须创造并维持一个第二审的JSPCONTEXT，称为JSP的背景封套。如果援引JSP的背景是一个实例PAGECONTEXT，JSP的背景封套还必须是一个实例PAGECONTEXT。GETJSPCONTEXT（）被调用时这个封套必须被归还。对于每次调用标签，JSP的背景封套必须出示一个明确的页面范围，它们必须对那些在援引JSP的背景相同，在JSP的背景封套时作出上述范围时必须作相应的修改更新工作。然而，任何页面范围的修改，必须不影响援引JSP的背景。对于每个公布和指定的属性，一个可变的网页必须建立在一个JSP的背景封套的页面范围。变量的名字必须和申报的属性名称相同。变量的价值必须在调用时通过的属性的价值。每个宣布的属性为可选并没有具体说明的，没有页面范围的变量就诞生了。如果标签接受动态属性，然后名字和价值观这些动态属性必须揭露以标签文件，详见作为表JSP82。对于所有意图和目的不同于同步的AT_BEGIN,NESTED,和AT_END脚本变量，有效的JSPCONTEXT标签文件是JSP的背景封套。举例来说，JSPCONTEXT脚本变量必须点到JSP的背景封套，而非援引JSP的背景。标签处理程序必须表现得好象标签库描述符登陆被界定为它一样，根据标签，属性，和可变指示出现在标签文件的翻译单位。对于一个将来的网页标签档案它是合法的标准行动。正如为JSP页面，远期是经过处理的请求调度。从REQUESTDISPATCHERFORWARD方法返回后，生成的标记处理器必须停止加工标签文件并扔出JAVAXSERVLETJSPSKIPPAGEEXCEPTION。同样，如果一个标签文件引用的一个典型标签处理程序，其中从DOENDTAG方法返回的SKIP_PAGE，或者如果它引用一个简单的标签处理，其中在DOTAGMETHOD中扔出SKIPPAGEEXCEPTION，生成的标记处理程序必须终止并且SKIPPAGEEXCEPTION必须被抛出。无论是这两种情况下，DOCATCH和DOFINALLY方法，必须被迫圈中标签，它在返回前执行TRYCATCHFINALLY接口。该圈中经典标签的DOENDTAG方法不能被执行。当从标签档案调用一个典型标签处理程序应该小心。一般来说，SIMPLETAG扩展可用于除SERLE