单项选择题 10.publicclassSuperCaic{11.protectedstaticintmultiply（inta，intb）{returna*b；}12.}and：20.publicclassSubCalcextendsSuperCalc{21.publicstaticintmultiply（inta，intb）{22.intc=super.multiply（a，b）；23.returnc；24.}25.}and：30.SubCalcsc=newSubCalc（）；31.System.out.println（sc.multiply（3，4））；32.System.out.println（SubCalc.multiply（2，2））；Whatistheresult？（）A.124B.Thecoderunswithnooutput.C.Anexceptionisthrownatruntime.D.Compilationfailsbecauseofanerrorinline21.E.Compilationfailsbecauseofanerrorinline22.F.Compilationfailsbecauseofanerrorinline31.

单项选择题 importjava.util.*；publicclassPQ{publicstaticvoidmain（String[]args）{PriorityQueuepq=newPriorityQueue（）；pq.add（”carrot”）；pq.add（”apple”）；pq.add（”banana”）；System.out.println（pq.poll（）+”：”+pq.peek（））；}}Whatistheresult？（）A.apple：appleB.carrot：appleC.apple：bananaD.banana：appleE.carrot：carrotF.carrot：banana

单项选择题 1.importjava.util.*；2.publicclassTestSet{3.enumExample{ONE，TWO，THREE}4.publicstaticvoidmain（String[]args）{5.Collectioncoll=newArrayList（）；6.coll.add（Example.THREE）；7.coll.add（Example.THREE）；8.coll.add（Example.THREE）；9.coll.add（Example.TWO）；10.coll.add（Example.TWO）；11.coll.add（Example.ONE）；12.Setset=newHashSet（coll）；13.}14.}Whichstatementistrueaboutthesetvariableonline12？（）A.Thesetvariablecontainsallsixelementsfromthecollcollection，andtheorderisguaranteedtobepreserved.B.Thesetvariablecontainsonlythreeelementsfromthecollcollection，andtheorderisguaranteedtobepreserved.C.Thesetvariablecontainsallsixelementsfromthecoilcollection，buttheorderisNOTguaranteedtobepreserved.D.Thesetvariablecontainsonlythreeelementsfromthecoilcollection，buttheorderisNOTguaranteedtobepreserved.

单项选择题 1.interfaceA{publicvoidaMethod（）；}2.interfaceB{publicvoidbMethod（）；}3.interfaceCextendsA，B{publicvoidcMethod（）；}4.classDimplementsB{5.publicvoidbMethod（）{}6.}7.classEextendsDimplementsC{8.publicvoidaMethod（）{}9.publicvoidbMethod（）{}10.publicvoidcMethod（）{}11.}Whatistheresult？（）A.Compilationfailsbecauseofanerrorinline3.B.Compilationfailsbecauseofanerrorinline7.C.Compilationfailsbecauseofanerrorinline9.D.IfyoudefineDe=newE（），thene.bMethod（）invokestheversionofbMethod（）definedinLine5.E.IfyoudefineDe=（D）（newE（）），thene.bMethod（）invokestheversionofbMethod（）definedinLine5.F.IfyoudefineDe=（D）（newE（）），thene.bMethod（）invokestheversionofbMethod（）definedinLine9.

单项选择题 11.classAnimal{publicStringnoise（）{returnpeep”；}}12.classDogextendsAnimal{13.publicStringnoise（）{returnbark”；}14.}15.classCatextendsAnimal{16.publicStringnoise（）{returnmeow”；}17.}.....30.Animalanimal=newDog（）；31.Catcat=（Cat）animal；32.System.out.printIn（cat.noise（））；Whatistheresult？（）A.peepB.barkC.meowD.Compilationfails.E.Anexceptionisthrownatruntime.

单项选择题 11.abstractclassVehicle{publicintspeed（）{return0；}}12.classCarextendsVehicle{publicintspeed（）{return60；}}13.classRaceCarextendsCar{publicintspeed（）{return150；}}......21.RaceCarracer=newRaceCar（）；22.Carcar=newRaceCar（）；23.Vehiclevehicle=newRaceCar（）；24.System.out.println（racer.speed（）+，?+car.speed（）25.+，+vehicle.speed（））；Whatistheresult？（）A.0，0，0B.150，60，0C.Compilationfails.D.150，150，150E.Anexceptionisthrownatruntime.

单项选择题 10.publicclassHello{11.Stringtitle；12.intvalue；13.publicHello（）{14.title+=World”；15.}16.publicHello（intvalue）{17.this.value=value；18.title=Hello”；19.Hello（）；20.}21.}and：30.Helloc=newHello（5）；31.System.out.println（c.title）；Whatistheresult？（）A.HelloB.HelloWorldC.Compilationfails.D.HelloWorld5E.Thecoderunswithnooutput.F.Anexceptionisthrownatruntime.

单项选择题 classClassA{publicintnumberOfinstances；protectedClassA（intnumberOfinstances）{this.numberOflnstances=numberOfinstances；}}publicclassExtendedAextendsClassA{privateExtendedA（intnumberOfinstances）{super（numberOflnstances）；}publicstaticvoidmain（String[]args）{ExtendedAext=newExtendedA（420）；System.out.print（ext.numberOflnstances）；}}Whichistrue？（）A.420istheoutput.B.Anexceptionisthrownatruntime.C.Allconstructorsmustbedeclaredpublic.D.ConstructorsCANNOTusetheprivatemodifier.E.ConstructorsCANNOTusetheprotectedmodifier.

单项选择题 publicclassBase{publicstaticfinalStringFOO=foo”；publicstaticvoidmain（String[]args）{Baseb=newBase（）；Subs=newSub（）；System.out.print（Base.FOO）；System.out.print（Sub.FOO）；System.out.print（b.FOO）；System.out.print（s.FOO）；System.out.print（（（Base）s）.FOO）；}}classSubextendsBase{publicstaticfinalStringFOO=bar；}Whatistheresult？（）A.foofoofoofoofooB.foobarfoobarbarC.foobarfoofoofooD.foobarfoobarfooE.barbarbarbarbarF.foofoofoobarbarG.foofoofoobarfoo

单项选择题 classDemoApp{publicstaticvoidmain（String[]args）{intx=5；inty=＋＋x＋x＋＋；System.out.println（y=”＋y＋”，x=”＋x）；}}以上程序运行后的输出结果是哪项？（）

单项选择题 Youarebuildingyourownlayoutmechanismbyincludingdynamiccontentforthepage’sheaderandfootersections.Thefooterisalwaysstatic，buttheheadergeneratesthe<title>tagthatrequiresthepagenametobespecifieddynamicallywhentheheaderisimported.WhichJSPcodesnippetperformstheimportoftheheadercontent？（）A.<jsp：includepage=’/WEB-INF/jsp/header.jsp’><jsp：paramname=’pageName’value=’WelcomePage’/></jsp：include>B.<jsp：importpage=’/WEB-INF/jsp/header.jsp’><jsp：paramname=’pageName’value=’WelcomePage’/></jsp：import>C.<jsp：includepage=’/WEB-INF/jsp/header.jsp’><jsp：attributename=’pageName’value=’WelcomePage’/>.</jsp：include>D.<jsp：importpage=’/WEB-INF/jsp/header.jsp’>.<jsp：attributename=’pageName’value=’WelcomePage’/>.</jsp：import>

单项选择题 WhichisabenefitofprecompilingaJSPpage？（）

单项选择题 TheJSPdeveloperwantsacommenttobevisibleinthefinaloutputtothebrowser.WhichcommentstyleneedstobeusedinaJSPpage？（）

单项选择题 WhichensuresthataJSPresponseisoftype'text／plain'？（）

单项选择题 WhichHttpSessionmethodstoresanobjectinasession？（）

单项选择题 ACompany.comdeveloperisdesigningamulti-tierwebapplicationanddiscoversaneedtohidethedetailsofestablishingandmaintainingremotecommunicationsfromtheclient.Inaddition，becausethebusinessandresourcetiersaredistributed，theapplicationneedstominimizetheinter-tiernetworktrafficrelatedtoservicingclientrequests.Whichdesignpatterns，workingtogether，addresstheseissues？（）A.FrontControllerandTransferObjectB.FrontControllerandServiceLocatorC.BusinessDelegateandTransferObjectD.BusinessdelegateandInterceptingFilterE.Model-View-ControllerandInterceptingFilter

单项选择题 Whichinterfacemustasessionattributeimplementifitneedstobenotifiedwhenawebcontainerpersistsasession？（）

单项选择题 AwebapplicationusestheHttpSessionmechanismtodetermineifauseris"loggedin."Whenausersuppliesavalidusernameandpassword，anHttpSessioniscreatedforthatuser.Theuserhasaccesstotheapplicationforonly15minutesafterloggingin.Thecodemustdeterminehowlongtheuserhasbeenloggedin，andifthistimeisgreaterthan15minutes，mustdestroytheHttpSession.Whichmethodin HttpSessionisusedtoaccomplishthis？（）A.GetcreationtimeB.InvalidateafterC.GetlastaccessedtimeD.Getmaxinactiveinterval

单项选择题 GivenanHttpServletRequestrequestandanHttpServletResponseresponse：41.HttpSessionsession=null；42.//insertcodehere43.if（session==null）{44.//dosomethingifsessiondoesnotexist45.}else{46.//dosomethingifsessionexists47.}Toimplementthedesignintent，whichstatementmustbeinsertedatline42？（）A.session=response.getSession（）；B.session=request.getSession（）；C.session=request.getSession（true）；D.session=request.getSession（false）；E.session=request.getSession（"jsessionid"）；

单项选择题 WhichmethodmustbeusedtoencodeaURLpassedasanargumenttoHttpServletResponse.sendRedirectwhenusingURLrewritingforsessiontracking？（）