戛Content。1.ScopeofSPobjects。2.ImplicitObjects。3,AnSPObjectApplicationExample&4.ExpressionLanguage(EL)2Bhy学1.ScopeofSPObjects3Bh9喜DefinitiononScopeofSPObjectsTheavailabilityofaSPobjectforusefromaparticularplaceoftheapplicationisdefinedasthescopeofthatSP0bject.2Bh9喜KindsObjectscopeinSPissegregatedintofourpartsaccordingtotheiravailablerangandlifetime。Pacescope。RedquestScope。SessionscopeApplicationscope21os5薯Pagescope。TheSPobjectcanbeaccessedonlyfromwithinthesamepagewhereitwascreated.Thedefaultscopefor3SP-objectscreatedusingtagispage.SPimplicitobjectsout,exception,response,config,pageContext,andpagehave“pagescope.2Bh9喜RequestscopeAJSPobjectcreatedusingtherequestscopecanbeaccessedfromanypagesthatservesthatrequest.。TheSPobjectwillbeboundtotherequestobject.。Implicitobjectrequesthastherequestscope:.2Bh9喜SessionscopetheSPobjectisaccessiblefrompagesthatbelongtothesamesessionfromwhereitwascreated.。TheJSPobjectthatiscreatedusingthesessionScopeisboundtothesessionobject.。ImplicitobjectsessionhastheSessionscope.2Bh9薯ApplicationscopeAJSPobjectcreatedusingtheapplicationscopecanbeaccessedfromanypagesacrosstheapplication.。TheJSPobjectisboundtotheapplicationobject.。Implicitobjectapplicationhasthe“applicationScope.2Bh9OperationonAttributesributeoperationmethodAnnotationpublicvoidsetAttribute(stringnameObjectob)Setthe“namerasthereferenceoftheobjectvob“publicObjectgetAttribute(Stringname)GetthevalueofattributenamepublicvoidremoveAtribute(StringnameRemovetheattributenamepublicEnumersticngeiAitibuteltamis01GetaltheatineutsswithintheavailebleccopepublicObjectgetAttribute(Stringnameintscope)publicvoidsetAttribute(stringnameObjectobjectintscope)publicvoidremoveAtribute(stringnameyintscopepublicEnumerationgetAtributeNamesInscopefintscope)SpecialmethodforPageContextUsedteaccessatribute“namerwithinscope“scope“.2Bh910学“2.ImplicitObiects3Bh9