计算机专业英文翻译

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1、UsingScriptingElementsImplicitJSPScriptingObjectsScriptingelementscanusepredefinedvariablesthatthecontainerassignsasreferencestoimplicitobjects(Table16-1)toaccessrequestandapplicationdata.TheseobjectsareinstancesofclassesdefinedbytheservletandJSPspecifications.AppendixDcont

2、ainscompletedescriptionsofallmethodsforeachclass,andtheyarebrieflyintroducedhereandusedinanumberofexamplesinthischapter.Table16-1.ImplicitJSPobjectsVariablenameJavatypeapplicationjavax.servlet.ServletContextconfigjavax.servlet.ServletConfigexceptionjava.lang.Throwableoutjav

3、ax.servlet.jsp.JspWriterpagejava•lang•ObjectpageContextjavax.servlet.jsp.PageContextrequestjavax•servlet•http-HttpServletRequestresponsejavax•servlet.http.HttpServletResponsesessionjavax.servlet.http.HttpSessionTheseobjectsprovideaccesstothesameinformation(andmore)astheimpl

4、icitvariablesyoucanuseinELexpressions,butit'snotaone-to-onematch:pageContextThepageContextvariablecontainsareferencetoaninstanceoftheclassnamedjavax.servlet.jsp.PageContext.Itprovidesmethodsforaccessingreferencestoalltheotherobjectsandattributesforholdingdatathatissharedbet

5、weencomponentsinthesamepage.It'sthesameobjectthatyoucanaccesswiththe${pageContext}ELexpression.Attributevaluesforthisobjectrepresentthepagescope;theyarethesameobjectsasareavailabletotheELworldasaMaprepresentedbythe${pageScope}expression.requestTherequestvariablecontainsaref

6、erencetoaninstanceofaclassthatimplementsaninterfacenamedjavax.servlet.http.HttpServletRequest.Itprovidesmethodsforaccessingalltheinformationthat*savailableaboutthecurrentrequest,suchasrequestparameters,attributes,headers,andcookies.It'sthesameobjectthatyoucanaccesswiththe${

7、pageContext.request}ELexpression.Attributevaluesforthisobjectrepresenttherequestscope;theyarethesameobjectsasareavailabletotheELworldasaMaprepresentedbythe${requestScope}expression.responseTheresponsevariablecontainsareferencetoanobjectrepresentingthecurrentresponsemessage.

8、Itsaninstanceofaclassthatimplementsthejavax.servlet.http.HttpServletResponseinterf