2024年Java認(rèn)證筆試歷年真題薈萃含答案

2024年Java認(rèn)證筆試歷年真題薈萃含答案（圖片大小可自由調(diào)整）答案解析附后卷I一.參考題庫(共25題)1.class?Rectangle?｛?? public?static?void?main（String?[]?args）?｛?? int?[]?x?＝?｛1，2，3｝；?? x[1]?＝?（x[1]?〉?1）?？?x[2]?：?0；?? System.out.println（x[1]）；?? ｝?? ｝?? 結(jié)果為：（）??A、0B、1C、2D、32.Which?code，?inserted?at?line?14，?allows?the?Sprite?class?to?compile？（） A、Direction?d?=?NORTH；B、Nav.Direction?d?=?NORTH；C、Direction?d?=?Direction.NORTH；D、Nav.Direction?d?=?Nav.Direction.NORTH；3.public?class?TestApp{?? public?static?void?main（String[]?args）{?? try{?? String?myname?=?null；?? if（myname.length（）>2）?? System.out.print（“1”）；?? }catch（NullPointerException?e）{?? System.out.print（“2”）；??}??}??}?? 上述程序運行后的輸出是哪項？（）?A、?1B、?12C、?21D、?24.現(xiàn)有：? class?Thread2?implements?Runnable??{????? void?run（）??{????? System.out.print?（"go¨）；????? }????? public?static?void?main（String??[]??args）??{??????? Thread2?t2=new?Thread2（）；????? Thread?t=new?Thread（t2）；????? t.start（）；????? }????? }????? 結(jié)果為：（）????A、goB、運行時異常被拋出C、代碼運行，無輸出結(jié)果D、編譯失敗5.現(xiàn)有：? 1.?interface?Animal?{? 2.?void?eat（）；? 3.?}? 4.? 5.?//?insert?code?here? 6.? 7.?public?class?HouseCat?extends?Feline?{? 8.?public?void?eat（）?{?}? 9.?}?? 和五個聲明：? abstract?class?Feline?implements?Animal?{?}? abstract?class?Feline?implements?Animal?{?void?eat（）；?}? abstract?class?Feline?implements?Animal?{?public?void?eat（）；?}? abstract?class?Feline?implements?Animal?{?public?void?eat（）?{?}?}? abstract?class?Feline?implements?Animal?{?abstract?public?void?eat（）；?}? 分別插入到第5行，有幾個可以通過編譯？（）?A、0B、1C、2D、36.Given?that?a?scoped?attribute?cart?exist?only?in?a?user’s?session，?which?two，?taken?independently，?ensure?the?scoped?attribute?cart?no?longer?exists？（）A、?${cart?=?null?}?B、??C、??D、??E、?cartF、??G、?${cart}7.public?class?Pet{???? private?String?name；???? public?Pet（）{? System.out.print（1）；????}? public?Pet（String?name）{??????? System.out.print（2）；????}?}? public?class?Dog?extends?Pet{???? public?Dog（）{? System.out.print（4）；????}? public?Dog（String?name）{??????? this（）；? System.out.print（3）；????}?}? 執(zhí)行new?Dog（“棕熊”）；后程序輸出是哪項？（）??A、?143B、?423C、?243D、?11348.Which?two?are?characteristics?of?the?Service?Locator?pattern？（）A、It?encapsulates?component?lookup?procedures.B、It?increases?source?code?duplication?and?decreases?reuse.C、It?improves?client?performance?by?caching?context?and?factory?objects.D、It?degrades?network?performance?due?to?increased?access?to?distributed?lookup?services.9.Click?the?Exhibit?button. Given?the?JSP?code： 1. 5. Which?two，?inserted?at?line?5，?output?the?name?of?the?product?in?the?response？（）A、 B、?C、?D、10.public?class?Employee{?? private?String?name；?? public?Employee（String?name）{?? ?=?name；??}?? public?String?getName（）{?? return?name；??}??}?? public?class?Manager?extends?Employee{?? private?String?department；?? public?Manager（String?name，String?department）{?? this.department?=?department；?? super（name）；?（應(yīng)于上一行掉位置）?? System.out.println（getName（））；??}??}?? Super的位置是否在方法的首行?? 執(zhí)行語句new?Manager（“smith”，”SALES”）后程序的輸出是哪項？（）A、?smithB、?nullC、?SALESD、?編譯錯誤11.Assume?the?tag?handler?for?a?st：simple?tag?extends?SimpleTagSupport. In?what?way?can?scriptlet?code?beused?in?the?body?of?st：simple？（）A、Set?the?body?content?type?to?JSP?in?the?TLDB、Scriptlet?code?is?NOT?legal?in?the?body?of?st：simple.C、Add?scripting-enabled="true"?to?the?start?tag?for?the?st：simple?elementD、Add?a?pass-through?Classic?tag?with?a?body?content?type?of?JSP?to?the?body?of?st：simple，?and?place?thescriptlet?code?in?the?body?of?that?tag12.String?s=?"hello"；???? String?t?=?"hello"；? char?c[]?=?{’h’，’e’，’l’，’l’，’o’}?；???? Which?return?true？（）???A、?s.equals（t）；B、?t.equals（c）；C、?s==t；D、?t.equals（new?String（"hello"））；E、?t==c；13.求四位的水仙花數(shù)。即滿足這樣條樣的四位數(shù)：各位數(shù)字的4次方和等于該數(shù)自身。14.Java語言中表達(dá)式-12>>3?的結(jié)果是哪項？（）?（12的二進(jìn)制00001100，-12的二進(jìn)制11110100）??A、?-4B、?-9C、?-1D、?-215.以下關(guān)于Java包的描述中，錯誤的是（）A、有利于程序的模塊與各個模塊的重復(fù)使用B、包是由一系列類和接口所組成的具有一定功能的集合C、一個包就是一個源文件D、兩個類如果名字相同，只要所屬的包不同，Java就會認(rèn)為它們是不同類16.一下關(guān)于內(nèi)容窗格的描述中，正確的是（）A、?內(nèi)容窗格直接屬于框架，是框架的重要組成部分B、?當(dāng)改變框架的大小時，內(nèi)容窗格的大小也自動改變C、?圖形界面的所有組件都放在內(nèi)容窗格上D、?內(nèi)容窗格放在分層窗格的深度為-30000的那一層，以保證它位于所有其他內(nèi)容的最下面E、?當(dāng)把組件放在框架上時，Java內(nèi)部時間實際上將它放到內(nèi)容窗格上17.Which?statement?is?true?for?the?class?java.util.ArrayList？（）??A、?The?elements?in?the?collection?are?ordered.B、?The?collection?is?guaranteed?to?be?immutable.C、?The?elements?in?the?collection?are?guaranteed?to?be?unique.D、?The?elements?in?the?collection?are?accessed?using?a?unique?key.E、?The?elements?in?the?collections?are?guaranteed?to?be?synchronized.18.現(xiàn)有：????? class?Pencil??{? public?void?write?（String?content）{? System.out.println?（"Write"+content）；?????}?????}? class?RubberPencil?extends?Pencil{?????public?void?write?（String?content）{? System.out.println?（"Rubber?Write"+content）；?????}? public?void?erase?（String?content）{?????System.out.println?（"Erase?"+content）；?????}?????} 執(zhí)行下列代碼的結(jié)果是哪項？（）? Pencil?pen=new?RubberPencil（）；????? pen.write（"Hello"）；?????A、??Write?HelloB、??Rubber?Write?HelloC、編譯錯誤D、運行時拋出異常19.Given：? int[]?myArray=newint[]?{1，?2，3，4，?5}；? What?allows?you?to?create?a?list?from?this?array？（）?A、?List?myList?=?myArray.asList（）；B、?List?myList?=?Arrays.asList（myArray）；C、?List?myList?=?new?ArrayList（myArray）；D、?List?myList?=?Collections.fromArray（myArray）；20.Which?declaration?prevents?creating?a?subclass?of?an?outer?class？（）A、?Static?class?FooBar{}B、?Private?class?FooBar{}C、?Abstract?public?class?FooBar{}D、?Final?public?class?FooBar{}E、?Final?abstract?class?FooBar{}21.What?is?the?numerical?range?of?a?char？（）???A、?0?...?32767B、?0?...?65535C、?–256?...?255D、?–32768?...?32767E、?Range?is?platform?dependent.22.Given：? 1.?public?class?Method?Over?{? 2.?public?void?set?Var?（int?a，?int?b，?float?c）?{? 3.?}? 4.?}?? Which?two?overload?the?set?Var?method（）？A、?private?void?set?Var（int?a，?float?c，?int?b）?{}B、?protected?void?set?Var（int?a，?int?b，?float?c）?{}C、?public?int?set?Var（int?a，?float?c，?int?b）?{return?a：}D、?public?int?set?Var（int?a，?int?b，?float?c）?{return?a：}E、?protected?float?set?Var（int?a，?int?b，?float?c）?{return?c：}23.下面的說法正確的是（）A、帶有頁作用域的對象在一個web應(yīng)用程序的每個JSP中都存在B、指令指定與一個特定的JSP?請求不相關(guān)的全局信息。C、當(dāng)JSP容器遇到開始定制標(biāo)簽和結(jié)束定制標(biāo)簽時，分別調(diào)用doInitBody方法和doAfterBody方法。D、動作只在翻譯時處理一次。24.Which?statements?concerning?the?value?of?a?member?variable?are?true，?when?no?explicit?assignments?have?been?made？（）??A、The?value?of?an?int?is?undetermined.B、The?value?of?all?numeric?types?is?zero.C、The?compiler?may?issue?an?error?if?the?variable?is?used?before?it?is?initialized.D、The?value?of?a?String?variable?is?""?（empty?string）.E、The?value?of?all?object?variables?is?null.25.HTTPS是使用（）來保證信息安全的。A、SETB、IPSECC、SSLD、SSH卷II一.參考題庫(共25題)1.Which?statement?of?assigning?a?long?type?variable?to?a?hexadecimal?value?is?correct？（）A、?long?number?=?345L；B、?long?number?=?0345；C、?long?number?=?0345L；D、?long?number?=?0x345L；2.對于滿足SQL92標(biāo)準(zhǔn)的SQL語句：? select?foo，count（foo）from?pokes?where?foo>10group?by?foo?having?count?（*）>5?order?by?foo?? 其執(zhí)行順序應(yīng)該是（）。A、FROM->WHERE->GROUP?BY->HAVING->SELECT->ORDER?BYB、FROM->GROUP?BY->WHERE->HAVING->SELECT->ORDER?BYC、FROM->WHERE->GROUP?BY->HAVING->ORDER?BY->SELECTD、FROM->WHERE->ORDER?BY->GROUP?BY->HAVING->SELECT3.通過Ajax，客戶端獲取的數(shù)據(jù)主要有兩種類型：文本型和（）4.Given?an?HttpServletRequest?request： 22.String?id?=?request.getParameter（"jsessionid"）； 23.//?insert?code?here 24.String?name?=?（String）?session.getAttribute（"name"）； Which?three?can?be?placed?at?line?23?to?retrieve?anexisting?HttpSession?object？（）A、HttpSession?session?=?request.getSession（）；B、HttpSession?session?=?request.getSession（id）；C、HttpSession?session?=?request.getSession（true）；D、HttpSession?session?=?request.getSession（false）；E、HttpSession?session?=?request.getSession（"jsessionid"）；5.Which?constructs?a?DataOutputStream？（）??A、?New?dataInputStream（“in.txt”）；B、?New?dataInputStream（new?file（“in.txt”））；C、?New?dataInputStream（new?writer（“in.txt”））；D、?New?dataInputStream（new?FileWriter（“in.txt”））；E、?New?dataInputStream（new?InputStream（“in.txt”））；F、?New?dataInputStream（new?FileInputStream（“in.txt”））；6.JAVA語言的下面幾種數(shù)組復(fù)制方法中，哪個效率最高（）。A、for循環(huán)逐一復(fù)制B、System.arraycopyC、System.copyofD、使用clone方法7.Which?HTTP?method?has?the?characteristic?that?multiple?indential?requests?may?produce?side?effect?beyond?those?of?a?single?request（）？A、?PUTB、?GETC、?INFOD、?POSTE、?HEADF、?TRACE8.java中下面哪個能創(chuàng)建并啟動線程（）。 A、AB、BC、CD、D9.如何設(shè)置彈性布局的約束？（）A、利用組件的setConstraints函數(shù)設(shè)置約束B、利用面板的setConstraints函數(shù)設(shè)置約束C、利用而已管理器的putConstraints函數(shù)設(shè)置約束D、利用SpringLayoutConstraints對象設(shè)置約束10.class?Output?｛? public?static?void?main（String?[]?args）?｛? int?i?＝?4；? System.out.print（"3"?+?i?+?"?"）；? System.out.print（i?+?4?+?"6"）；? System.out.println（i?+?"7"）；? ｝? ｝? 結(jié)果為（）?A、7?8611B、7?44647C、34?8611D、34?864711.//point?X? public?class?foo?（? public?static?void?main?（String[]args）?throws?Exception?{? printWriter?out?=?new?PrintWriter?（new? java.io.outputStreamWriter?（System.out），?true；? out.printIn（“Hello”）；? }? ）?? Which?statement?at?PointX?on?line?1?allows?this?code?to?compile?and?run？（）??A、?Import?java.io.PrintWriter；B、?Include?java.io.PrintWriter；C、?Import?java.io.OutputStreamWriter；D、?Include?java.io.OutputStreamWriter；E、?No?statement?is?needed.12.現(xiàn)有? class?Parser?extends?Utils?{? public?static?void?main?（String??[]??args）??{? try??{??System.out.print?（new?Parser?（）?.getlnt?（"42"））?????? }??catch?（Exception?e）?{? System.out.println?（"Exc"）?；??}????? }? int?getlnt?（String?arg）??throws?Exception??{???? return?Integer.parselnt?（arg）?；????? }????? }? class?Utils?{? int?getlnt?（）??{??return?42；??}???? }? 結(jié)果是什么？（）??????A、?42ExcB、?ExcC、?42D、編譯失敗13.下列有關(guān)main（）方法的簽名正確的是哪些？（）A、?public?static?void?main（String[]?args）{}B、?public?static?void?main（）{}C、?public?static?void?main（String?args[]）{}D、?public?void?static?main（String[]?args）{}14.String?a?=?“ABCD”；? String?b?=?a.toLowerCase（）；? b.replace（‘a(chǎn)’，?‘d’）；? b.replace（‘b’，?‘c’）；? System.out.println（b）；?? What?is?the?result？?（）?A、?abcdB、?ABCDC、?dccdD、?dcbaE、?Compilation?fails.F、?An?exception?is?thrown?at?runtime.15.下面哪些類可用于throw語句（）A、ErrorB、ExceptionC、EventD、Throwable16.下面有關(guān)struts1和struts2的區(qū)別，描述錯誤的是（）。A、Struts1要求Action類繼承一個抽象基類。Struts?2?Action類可以實現(xiàn)一個Action接口B、Struts1?Action對象為每一個請求產(chǎn)生一個實例。Struts2?Action是單例模式并且必須是線程安全的C、Struts1?Action?依賴于Servlet?API，Struts?2?Action不依賴于容器，允許Action脫離容器單獨被測試D、Struts1?整合了JSTL，Struts2可以使用JSTL，但是也支持OGNL17.What?is?the?result？（） A、hi?hiB、hi?worldC、world?worldD、Compilation?fails.E、An?exception?is?thrown?at?runtime.18.Less?Test{??? public?static?void?main（String[]?args）{?? for（int?x=0；x<7；++x）{? int?y=2；?? x=++y；?? }?? System.out.println（“y=”+y）；?? }?? }?? 結(jié)果為：（）??A、y=5B、y=6C、?y=7D、y=8E、編譯失敗F、運行時異常被拋出19.編寫一個應(yīng)用程序，對程序中給定的四個double型數(shù)據(jù)求其最大值和最小值。20.public?class?Pass?{? public?static?void?main（String?[1?args）?{? int?x?5；? Pass?p?=?new?Pass（）；? p.doStuff（x）；? System.out.print（”?main?x?=?“+?x）；? }? void?doStuff（int?x）?{? System.out.print（”?doStuff?x?=?“+?x++）；? }? }? What?is?the?result？（）?A、?Compilation?fails.B、?An?exception?is?thrown?at?runtime.C、?doStuffx?=?6?main?x?=?6D、?doStuffx?=?5?main?x?=?5E、?doStuffx?=?5?main?x?=?6F、?doStuffx?=?6?main?x?=?521.編寫一個程序，能將一個Java源程序中的空行及注釋去掉。22.A?JSP?page?needs?to?instantiate?a?JavaBean?to?be?used?by?only?that?page.?Which?two?jsp：useBean?attributes?must?be?used?to?access?this?attribute?in?the?JSP?page？（）A、?idB、?typeC、?nameD、?classE、?scopeF、?create23.現(xiàn)有：? interface?Data?{public?void?load（）；}? abstract?class?Info?{public?abstract?void?load（）；}????? 下列類定義中正確使用Data和Info的是哪項？（）?A、?public?class?Employee?implements?Info?extends?Data?{?public?void?load（）{／*dosomething*／}?????}B、public?class?Employee?extends?Inf.implements?Data{?public?void?load（）?{／*do?something*／}?????}C、public?class?Empl.yee?implements?Inf?extends?Data{?public?void?Data.1oad（）{*?do?something*／}?????public?void?load（）{／*do?something*／}?????}D、public?class?Employee?extends?Inf?implements?Data??{??public?void?Data.1oad（）??{／*do?something*／）?????public?void?info.1oad（）{/*do?something*/}????}24.Given?the?following?code：???? 1）?class?Parent?{???? 2）?private?String?name；???? 3）?public?Parent（）{}???? 4）?}? 5）?public?class?Child?extends?Parent?{???? 6）?private?String?department；? 7）?public?Child（）?{}? 8）?public?String?getValue（）{?return?name；?}???? 9）?public?static?void?main（String?arg[]）?{???? 10）?Parent?p?=?new?Parent（）；???? 11）?}? 12）?}? Which?line?will?cause?error？（）???A、?line?3B、?line?6C、?line?7D、?line?8E、?line?1025.Java語言中常量的定義是哪項？（）A、?public?staticB、?public?static?finalC、?finalD、?public?static?abstract卷III一.參考題庫(共25題)1.Which?two?statements?are?reserved?words?in?Java？（）?????????A、?RunB、?ImportC、?DefaultD、?Implement2.用迭代法編寫程序用于求解立方根。3.求數(shù)列2，4，8，16，32，…前若干項之和。當(dāng)和大于9000時，終止求和并輸出結(jié)果4.下面哪些代碼為正確的（）A、B、C、D、5.How?do?objects?pass?messages?in?Java？（）???A、They?pass?messages?by?modifying?each?other’s?member?variablesB、They?pass?messages?by?modifying?the?static?member?variables?of?each?other’s?classesC、They?pass?messages?by?calling?each?other’s?instance?member?methodsD、They?pass?messages?by?calling?static?member?methods?of?each?other’s?classes.6.表達(dá)式““.equals（null）的結(jié)果為x=10； 36.do{ 37.x--； 38.}while（x<10）； Howmanytimeswillline37beexecuted？（）A、tentimesB、zerotimesC、onetometimesD、morethantentimes8.1.?public?class?enclosingone?（? 2.?public?class?insideone{}? 3.?）? 4.?public?class?inertest（? 5.?public?static?void?main?（string[]args）（? 6.?enclosingone?eo=?new?enclosingone?（）；? 7.?//insert?code?here? 8.?）? 9.?）??? Which?statement?at?line?7?constructs?an?instance?of?the?inner?class？（）??A、?InsideOnew?ei=?eo.new?InsideOn（）；B、?Eo.InsideOne?ei?=?eo.new?InsideOne（）；C、?InsideOne?ei?=?EnclosingOne.new?InsideOne（）；D、?EnclosingOne.InsideOne?ei?=?eo.new?InsideOne（）；9.this（）表示（）A、引用當(dāng)前對象B、調(diào)用當(dāng)前對象C、調(diào)用當(dāng)前對象的方法D、調(diào)用當(dāng)前對象的構(gòu)造函數(shù)10.You?want?subclasses?in?any?package?to?have?access?to?members?of?a?superclass.?Which?is?the?most?restrictive?access?that?accomplishes?this?objective？（）??A、?publicB、?privateC、?protectedD、?transientE、?default?access11.Click?the?'Select?and?Place'?button. Place?the?events?in?the?order?they?occur. 12.java語言中，按照一定格式生成程序的文檔的工具是（）。A、javacB、javahC、javadocD、jar13.現(xiàn)有：D?? -?f?是一個對?java.io.File?實例的合法引用?? -?fw?是一個對?java.io.FileWriter?實例的合法引用?? -?bw?是一個對?java.io.BufferedWriter?實例的合法引用?? 以下哪一項無效？（）??A、?PrintWriter?prtWtr?＝?new?PrintWriter（f）；B、?PrintWriter?prtWtr?＝?new?PrintWriter（fw）；C、?PrintWriter?prtWtr?＝?new?PrintWriter（bw）；D、?BufferWriter?bufWtr?＝?new?BufferedWriter（f）；E、?BufferWriter?bufWtr?＝?new?BufferedWriter（fw）；F、?BufferWriter?bufWtr?＝?new?BufferedWriter（bw）；14.有5個人坐在一起，問第五個人多少歲？他說比第4個人大2歲。問第4個人歲數(shù)，他說比第3個人大2歲。問第三個人，又說比第2人大兩歲。問第2個人，說比第一個人大兩歲。最后問第一個人，他說是10歲。請問第五個人多大？15.現(xiàn)有：? class??Test4??{? public?static?void?main?（String??[]??args）??{??? boolean?X=true；?? boolean?y=false；??? short?Z=42；??? if（（z++==42）??＆＆??（y=true））z++；??? if（（x=false）??||????（++z==45））??z++；??? System.?out.println（¨z=”+z）；??? ?}??? }? 結(jié)果為：（）?A、??Z=42B、??z=44C、??Z=?45D、??z=?4616.現(xiàn)有：? class?HorseRadish??{????? ／／insert?code?here? protected?HorseRadish?（int?x）????{????? System.out.println?（"bok?choy"）；????? }????? }? class?Wasabi?extends?HorseRadish??{? public?static?void?main?（String??[]??args）{??? Wasabi?w-?new?Wasabi（）；???? }???? }? 分別插入到第2行，哪兩項允許代碼編譯并產(chǎn)生”bok?choy”輸出結(jié)果（）A、?protected?HorseRadish（）??{this?（42）；}B、??protected?HorseRadish（）??{}C、??／／just?a?commentD、??protected??HorseRadish（）??{??new?HorseRadish?（42）；}17.關(guān)于以下application，說法正確是什么（）。 A、4行與9行不能通過編譯，因為缺少方法名和返回類型B、編譯通過，執(zhí)行結(jié)果是：x=5C、編譯通過，執(zhí)行結(jié)果是：x=3D、9行不能通過編譯，因為只能有一個靜態(tài)初始化器18.java接口的方法修飾符可以為（）。（忽略內(nèi)部接口）A、privateB、protectedC、finalD、abstract19.12.?String?csv?=?“Sue，5，true，3”；? 13.?Scanner?scanner?=?new?Scanner（?csv）；? 14.?scanner.useDelimiter（”，”）；? 15.?int?age?=?scanner.nextInt（）；? What?is?the?result？（）?A、?Compilation?fails.B、?After?line?15，?the?value?of?age?is?5.C、?After?line?15，?the?value?of?age?is?3.D、?An?exception?is?thrown?at?runtime.20.我們定義一個Account類來描述銀行賬戶，銀行賬戶有賬戶名、金額等屬性特征，同時有存款、取款等行為特征，下述代碼適合描述的是哪項？（）?????A、class??Accountf?????

String?name；／／賬戶?????S

tring?amount；??／／金額?????

Account?（String?name）（????）

void?deposit?（double?mount）{??／／存款?????）

void?withdraw?（double?mount）{??／／取款?????}?????）B、class??Accountf?????

String?name；／／賬戶d

ouole?amount；??／／金額?????

Account（double?amount）{???}

void?deposit?（double?mount）{??／／存款?????）

void?withdraw?（double?mount）{??／／取款?????）?????）C、class??Accountf?????

String?name；／／賬戶

double?amount；??／／金額????

?Account?（String?name）{}

void?deposit?（double?mount）{／／存款?????）?