2024年計(jì)算機(jī)考試-Java認(rèn)證考試近5年真題附答案

（圖片大小可自由調(diào)整）2024年計(jì)算機(jī)考試-Java認(rèn)證考試近5年真題薈萃附答案第I卷一.參考題庫(共100題)1.Which?three?statements?are?true？（）A、?The?default?constructor?initializes?method?variables.B、?The?default?constructor?has?the?same?access?as?its?class.C、?The?default?constructor?invoked?the?no-arg?constructor?of?the?superclass.D、?If?a?class?lacks?a?no-arg?constructor，?the?compiler?always?creates?a?default?constructor.?E、?The?compiler?creates?a?default?constructor?only?when?there?are?no?other?constructors?for?theclass.2.哪兩個(gè)是同步的？（）A、?java.util.TreeSetB、?java.util.HashtableC、?java.util.VectorD、?java.util.LinkedList3.多態(tài)應(yīng)用于（）A、重載B、覆蓋C、實(shí)現(xiàn)D、組合4.以下哪個(gè)類與Swing?GUI菜單類無關(guān)？（）?A、JMenuB、JMenuBarC、JMenuItemD、以上皆是5.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=?466.已知： 則下面哪段代碼是合法的（）A、B、C、D、7.什么是多態(tài)？面向?qū)ο蟪绦蛟O(shè)計(jì)為什么要引人多態(tài)的特性？使用多態(tài)有什么優(yōu)點(diǎn)？8.You?need?to?create?a?JavaBean?object?that?is?used?only?within?the?current?JSP?page.?It?must?NOT?beaccessible?to?any?other?page?including?those?that?this?page?might?import. Which?JSP?standard?action?canaccomplish?this?goal？（）A、B、C、D、9.this（）和super（）只能位于構(gòu)造函數(shù)中的第一句10.Socket通常也稱為套接字，用于描述（）和（）11.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.12.1.publicclassGC{ 2.privateObjecto； 3.privatevoiddoSomethingElse（Objectobj）{o=obj；} 4.publicvoiddoSomething（）{ 5.Objecto=newObject（）； 6.doSomethingElse（o）； 7.o=newObject（）； 8.doSomethingElse（null）； 9.o=null； 10.} 11.} WhenthedoSomethingmethodiscalled，afterwhichlinedoestheObjectcreatedinline5becomeavailableforgarbagecollection？（）A、Line5B、Line6C、Line7D、Line8E、Line9F、Line1013. What?is?the?result？（）A、?baz?has?a?value?of?0.B、?baz?has?a?value?of?1.C、?baz?has?the?value?of?2.D、?An?exception?is?thrown.E、?The?code?will?not?compile.14.涉及類MyClass的方法簽名足public?void??find（MyClass?a），那么該方法可接收的實(shí)際參數(shù)的類型可以是哪些？（）??A、MyClass類的類型B、MyClass子類的類型C、Object類型D、所有接口15.In?which?two?cases?does?the?compiler?supply?a?default?constructor?for?class?A？（）??A、?class?A{}B、?class?A?{?public?A（）{}?}C、?class?A?{?public?A（int?x）{}?}D、?class?Z?{}?class?A?extends?Z?{?void?A（）{}?}16.下面正確的創(chuàng)建Socket的語句是（）A、?Socket?a??=??new?Soeket（80）：B、?Socket?b??=??new?Socket（"130.?3.?4.?5"，?80）：C、?ServerSocket?c??=??new?Socket（80）D、?ServerSocket?d?=??new?Socket?（"130.?3.?4，?5"，?80）17.Assume?the?scoped?attribute?priority?does?NOT?yet?exist.?Which?two?create?and?set?new?request-scoped?attribute?priority?to?the?value?“medium”？（）?A、?${priority?=?‘medium’?}?B、?${requestScope[?‘priority’?]?=?‘medium’?}?C、??D、?medium?E、??F、?medium?G、?18.中間容器，原子組件，菜單欄，工具欄等都直接放在頂級容器下。19.What?is?the?result？（） A、Compilation?succeeds.B、Exactly?one?class?does?NOT?compile.C、Exactly?two?classes?do?NOT?compile.D、Exactly?four?classes?do?NOT?compile.E、Exactly?three?classes?do?NOT?compile.20.多線程之間怎樣進(jìn)行同步？21.What?is?the?result？（） A、hi?hiB、hi?worldC、world?worldD、Compilation?fails.E、An?exception?is?thrown?at?runtime.22.下面哪些說法是正確的（）A、靜態(tài)方法不能被覆蓋B、私有方法不能被重載C、實(shí)例變量能夠被隱藏D、靜態(tài)方法能夠被重載23.猴子摘桃問題猴子第1天摘下若干桃子，當(dāng)即吃掉一半，又多吃一個(gè)，第二天將剩余的部分吃掉一半還多一個(gè)；以此類推，到第10天只剩余1個(gè)。問第1天共摘了多少桃子24.現(xiàn)有如下類型：?? a?-?java.util.Hashtable? b?-?java.util.List? c?-?java.util.ArrayList? d?-?java.util.SortedSet? 和定義：? 1?–?使用本接口，允許用戶控制集合中每個(gè)元素的插入位置。?? 2?–?使用本集合，確保用戶可以按照遞增或元素的自然順序遍歷集合。?? 3?–?本具體類型允許空元素及基于索引的訪問。??? 4?–?本集合是同步的。?? 哪一組匹配是對的？（）?A、?1?描述?b；?3?描述?c。B、?2?描述?d；?3?描述?b。C、?3?描述?a；?4?描述?b。D、?4?描述?a；?2?描述?c。25.public?class?Plant?{? private?String?name；? public?Plant（String?name）?{??=?name；?}? public?String?getName（）?{?return?name；?}? }? public?class?Tree?extends?Plant?{? public?void?growFruit（）?{?}? public?void?dropLeaves（）?{?}? }? Which?is?true？（）?A、?The?code?will?compile?without?changes.B、?The?code?will?compile?if?public?Tree（）?{?Plant（）；?}?is?added?to?the?Tree?class.C、?The?code?will?compile?if?public?Plant（）?{?Tree（）；?}?is?added?to?the?Plant?class.D、?The?code?will?compile?if?public?Plant（）?{?this（”fern”）；?}?is?added?to?the?Plant?class.E、?The?code?will?compile?if?public?Plant（）?{?Plant（”fern”）；?}?is?added?to?the?Plant?class.26.Which?two?create?an?instance?of?an?array？（）?A、?int?ia?=?new?int?[15]；B、?float?fa?=?new?float?[20]；C、?char?ca?=?“Some?String”；D、?Object?oa?=?new?float[20]；E、?Int?ia?=?（4，?5，?6）?（1，?2，?3）27.public?abstract?class?Shape?{? int?x；? int?y；? public?abstract?void?draw（）；? public?void?setAnchor（int?x，?int?y）?{? this.x?=?x；? this.y?=?y；? }? }? and?a?class?Circle?that?extends?and?fully?implements?the?Shape?class.?Which?is?correct？（）?A、?Shape?s?=?new?Shape（）；?s.setAnchor（10，10）；?s.draw（）；B、?Circle?c?=?new?Shape（）；?c.setAnchor（10，10）；?c.draw（）；C、?Shape?s?=?new?Circle（）；?s.setAnchor（10，10）；?s.draw（）；D、?Shape?s?=?new?Circle（）；?s->setAnchor（10，10）；?s->draw（）；E、?Circle?c?=?new?Circle（）；?c.Shape.setAnchor（10，10）；?c.Shape.draw（）；28.ArraryList?a?=?new?ArrayList（）；? a.add（“Alpha”）；? a.add（“Bravo”）：? a.add（“Charlie”）；? a.add（“Delta”）；? Iterator?iter?=?a.iterator（）； Which?two，?added?at?line?17，?print?the?names?in?the?ArrayList?in?alphabetical?order？（）A、?for?（int?i=0；?i29.class?java?{? public?static?void?main（String?[]?java）?{?? for?（int?Java?=?1；?Java?〈?java.length；?Java++）?? System.out.print（"java?"）；?? }?? }?? 和命令行：? java?java?java?java?java?? 結(jié)果為：（）??A、javaB、java?javaC、java?java?javaD、編譯失敗30.Click?the?’Select?and?Place’?button. Place?the?events?in?the?order?they?occur. 31.Which?thetwo?are?true?about?the?JSTL?core?iteration?custom?tags？（）A、?It?may?iterate?over?arrays，?collections，?maps?and?strings.B、?The?body?of?the?tag?may?contain?EL?code，?but?not?scripting?code.C、?When?looping?over?collections，?a?loop?status?object?may?be?used?in?the?tag?body.D、?It?may?iterate?over?a?map，?but?only?the?key?of?the?mapping?may?be?used?in?the?tag?body.E、?When?looping?over?integers?（for?example?begin1=’1’?end=’10’），?a?loop?status?object?may?not?beused?in?the?tag?body.32.在Swing中，一下列出的面板的作用中，錯(cuò)誤的是（）A、?放置并排列組件B、?顯示背景圖案C、?接收事件D、?顯示面板的邊框33.package?test；? class?Target?{? public?String?name?=?“hello”；? }? What?can?directly?access?and?change?the?value?of?the?variable?name？（）?A、?any?classB、?only?the?Target?classC、?any?class?in?the?test?packageD、?any?class?that?extends?Target34.Which?statements?concerning?the?effect?of?the?statement?gfx.drawRect（5，?5，?10，?10）?are?true，?given?that?gfx?is?a?reference?to?a?valid?Graphics?object？（）??A、The?rectangle?drawn?will?have?a?total?width?of?5?pixels.B、The?rectangle?drawn?will?have?a?total?height?of?6?pixels.C、The?rectangle?drawn?will?have?a?total?width?of?10?pixels.D、The?rectangle?drawn?will?have?a?total?height?of?11?pixels.35.1）?class?Person?{? 2）?public?void?printValue（int?i，?int?j）?{/*…*/?}???? 3）?public?void?printValue（int?i）{/*...*/?}???? 4）?}? 5）?public?class?Teacher?extends?Person?{???? 6）?public?void?printValue（）?{/*...*/?}???? 7）?public?void?printValue（int?i）?{/*...*/}???? 8）?public?static?void?main（String?args[]）{???? 9）?Person?t?=?new?Teacher（）；???? 10）?t.printValue（10）；???? 11）?}??? 12）?}? Which?method?will?the?statement?on?line?10?call？?（）??A、?on?line?2B、?on?line?3C、?on?line?6D、?on?line?736.public?class?Person?{? private?String?name，?comment；? private?int?age；? public?Person（String?n，?int?a，?String?c）?{? name?=?n；?age?=?a；?comment?=?c；? }? public?boolean?equals（Object?o）?{? if（!?（o?instanceof?Person））?return?false；? Person?p?=?（Person）o；? return?age?==?p.age?&&?name.equals（）；? }? }? What?is?the?appropriate?definition?of?the?hashCode?method?in?class?Person？（）?A、?return?super.hashCode（）；B、?return?name.hashCode（）?+?age?*?7；C、?return?name.hashCode（）?+?comment.hashCode（）?/2；D、?return?name.hashCode（）?+?comment.hashCode（）?/?2?-?age?*?3；37.class?Account?{?? private?int?balance；?? public?void?setBalance（int?b）?{?balance?=?b；?}? public?int?getBalance（）?{?return?balance；?}?? public?void?clearBalance（）?{?balance?=?0；?}?? }?? 哪一個(gè)改變可以使?Account?類線程安全？（）?A、在第2行加?synchronized?修飾符。B、在第3行加?synchronized?修飾符。C、在第3行、第4行和第6行加?synchronized?修飾符。D、在第4行、第6行和第8行加?synchronized?修飾符。38.Which?statement?is?true？（）??A、?A?flow?layout?can?be?used?to?position?a?component?that?should?resize?horizontally?when?the??container?is?resized.B、?A?grid?layout?can?be?used?to?position?a?component?tat?should?maintain?a?constant?size?even?when??the?container?is?resized.C、?A?border?layout?can?be?used?to?position?component?that?should?maintain?a?constant?size?even?when??the?container?is?resized.D、?The?grid?bag?layout?can?be?used?to?give?a?grid-like?layout?which?differs?from?the?normal?grid?in?that?individual?rows?and?columns?can?have?unique?sizes.E、?If?two?components?are?placed?in?the?same?column?of?a?grid?bag?layout，?and?one?component?resizes?horizontally，?then?the?other?component?must?resize?horizontally.39. What?is?the?value?of?the?variable?output?at?line?24？??40.public?static?void?main（String[]?args）?{? try?{? args=null；? args[0]?=?“test”；? System.out.println（args[0]）；? }?catch?（Exception?ex）?{? System.out.println（”Exception”）；? }?catch?（NullPointerException?npe）?{? System.out.println（”NullPointerException”）；? }? }? What?is?the?result？（）?A、?testB、?ExceptionC、?Compilation?fails.D、?NullPointerException41.In?which?two?web?application?directories?can?dependent?classes?and?libraries?be?located？?（）A、?/WEB-INF/lib?as?a?JAR?fileB、?/META-INF/lib?as?a?JAR?fileC、?/classes?as?compiled?class?filesD、?/WEB-INF/lib?as?compiled?class?filesE、?/WEB-INF/classes?as?compiled?class?filesF、?/META-INF/classes?as?compiled?class?files42.以下關(guān)于Swing容器敘述，哪項(xiàng)錯(cuò)誤？（）?A、容器是一種特殊的組件，它可用來放置其它組件B、容器是組成GUI所必需的元素C、容器是一種特殊的組件，它可被放置在其它容器中D、容器是一種特殊的組件，它可被放置在任何組件中43.A?RequestDispatcher?can?be?obtained?from?which?two?objects？?（）A、?ServletConfigB、?ServletContextC、?HttpServletRequestD、?HttpServletResponse44.javax.swing.JPopMenu類可用于（）?A、?創(chuàng)建菜單項(xiàng)B、?創(chuàng)建按鈕C、?創(chuàng)建菜單欄D、?創(chuàng)建彈出式菜單45.內(nèi)部類與外部類的使用有何不同？46.public?class?Person?{? private?name；? public?Person（String?name）?{? ?=?name；? }? public?boolean?equals（Object?o）?{? if（?!o?instanceof?Person?）?return?false；? Person?p?=?（Person）?o；? return?.equals（）；? }? }? Which?is?true？（）?A、?Compilation?fails?because?the?hashCode?method?is?not?overridden.B、?A?HashSet?could?contain?multiple?Person?objects?with?the?same?name.C、?All?Person?objects?will?have?the?same?hash?code?because?the?hashCode?method?is?not?overridden.D、?If?a?HashSet?contains?more?than?one?Person?object?with?name=”Fred”，?then?removing?anotherperson，?also?with?name=”Fred”，?will?remove?them?all.47.What?is?the?result？（） A、Compilation?fails.B、atom?graniteC、granite?graniteD、atom?granite?graniteE、An?exception?is?thrown?at?runtime.F、atom?granite?atom?granite48.按鈕的事件處理類的主要作用是什么？（）A、根據(jù)用戶點(diǎn)擊及時(shí)修改按鈕的外觀B、監(jiān)聽用戶對按鈕的點(diǎn)擊，及時(shí)作出響應(yīng)C、展示按鈕點(diǎn)擊時(shí)的動(dòng)畫效果D、設(shè)置按鈕對哪一類事件有反應(yīng)49.下面有關(guān)JVM內(nèi)存，說法錯(cuò)誤的是（）。A、程序計(jì)數(shù)器是一個(gè)比較小的內(nèi)存區(qū)域，用于指示當(dāng)前線程所執(zhí)行的字節(jié)碼執(zhí)行到了第幾行，是線程隔離的B、Java方法執(zhí)行內(nèi)存模型，用于存儲局部變量，操作數(shù)棧，動(dòng)態(tài)鏈接，方法出口等信息，是線程隔離的C、方法區(qū)用于存儲JVM加載的類信息、常量、靜態(tài)變量、即使編譯器編譯后的代碼等數(shù)據(jù)，是線程隔離的D、原則上講，所有的對象都在堆區(qū)上分配內(nèi)存，是線程之間共享的50.For?a?given?ServletResponse?response，which?two?retrieve?an?object?for?writing?text?data？（）A、response.getWriter（）B、response.getOutputStream（）C、response.getOutputWriter（）D、response.getWriter（）.getOutputStream（）E、response.getWriter（Writer.OUTPUT_TEXT）51.下列敘述正確的是哪項(xiàng)？（）A、事件繼承模型取代事件委托模型B、事件繼承模型比事件委托模型更加高效C、事件委托模型使用事件監(jiān)聽器來定義事件處理類的方法D、事件委托模型使用handleEvent（）方法來支持事件處理52.類中不允許定義私有的構(gòu)造函數(shù)53.public?class?test?（?? public?static?void?main（string?args）?{?? int?1=?0；?? while?（i）?{?? if?（i==4）?{?? break；? }?? ++i；? }?? }?? ）?? What?is?the?value?of?i?at?line?10？（）A、?0B、?3C、?4D、?5E、?The?code?will?not?compile.54.以下關(guān)于Java文件名的敘述，正確的有？（）A、Java源文件的擴(kuò)展名應(yīng)為.javaB、Java源文件的文件名應(yīng)與文件中的類名一致C、Java字節(jié)碼文件的擴(kuò)展名應(yīng)為.javaD、一個(gè)Java源文件中只能包含一個(gè)Java類55.關(guān)于object類，以下描述中正確的有（）A、object類中定義了一些重要的成員函數(shù)和變量，以方便JAVA類的使用B、object類是所有其他JAVA類的直接或間接父類C、object類是一個(gè)非常特殊的“虛擬”類，也就是說，你只能叢object類中派生出其他類，但不能創(chuàng)建一個(gè)object類的對象。D、如果一個(gè)類已經(jīng)有了父類，那么這個(gè)類同時(shí)繼承了object類，也就是說，這時(shí)候這個(gè)類實(shí)際上有2個(gè)父類E、由于JAVA中的類是單繼承的，因此所有的類以object類為根形成了一棵繼承樹56.A?developer?is?designing?a?web?application?that?makes?many?fine-grained?remote?data?requests?for?eachclient?request.?During?testing，?the?developer?discovers?that?the?volume?of?remote?requests?significantlydegrades?performance?of?the?application. Which?design?pattern?provides?a?solution?for?this?problem？（）A、FlyweightB、Transfer?ObjectC、Service?LocatorD、Dispatcher?ViewE、Business?DelegateF、Model-View-Controller57.有一個(gè)三位數(shù)滿足下列條件：? （1）三位數(shù)字各不相同；? （2）此數(shù)等于它的各位數(shù)字的立方和。求這種三位數(shù)的個(gè)數(shù)58.程序員正在進(jìn)行一個(gè)項(xiàng)目，必須實(shí)現(xiàn)equals方法與所給的hashCode方法協(xié)調(diào)運(yùn)行：? public?int?hashCode（）?{??? return?（size.hashCode（）?+?color.hashCode（））?*?17；??? }??? 哪一個(gè)equals方法支持此目標(biāo)？（）?A、?無法確定B、?public?boolean?equals（Object?o）?{??Sock?s?=?（Sock）?o；?return?size.equals（s.size）；}C、?public?boolean?equals（Object?o）?{??Sock?s?=?（Sock）?o；?return?color.equals（s.color）；}D、?public?boolean?equals（Object?o）?{??Sock?s?=?（Sock）?o；?return?size.equals（s.size）?&&color.equals（s.color）；??}59.11.publicclassCommander{ 12.publicstaticvoidmain（String[]args）{ 13.StringmyProp=/*insertcodehere*/ 14.System.out.println（myProp）； 15.} 16.} andthecommandline： java-Dprop.custom=gobstopperCommander Whichtwo，placedonline13，willproducetheoutputgobstopper？（）A、System.load（"prop.custom"）；B、System.getenv（"prop.custom"）；C、Sperty（"prop.custom"）；D、System.getProperty（"prop.custom"）；E、System.getProperties（）.getProperty（"prop.custom"）；60.在一個(gè)彈性布局的面板中，如果有10個(gè)組件的話，最少需要多少條約束？（）??A、10條B、22條C、2條D、40條61.byte?[]?arry1，?array2[]；? byte?array3?[][]；? byte[][]?array4；?? If?each?array?has?been?initialized，?which?statement?will?cause?a?compiler?error？（）??A、?Array2?=?array1；B、?Array2?=?array3；C、?Array2?=?array4；D、?Both?A?and?BE、?Both?A?and?CF、?Both?B?and?C62.Click?the?Exhibit?button. The?h：highlight?tag?renders?its?body，?highlighting?an?arbitrary?number?of?words，?each?of?which?is?passed?asan?attribute?（word1，?word2，?...）.?For?example，?a?JSP?page?can?invoke?theh：highlight?tag?as?follows： 11.? 12.?high?medium?low 13.? Given?that?HighlightTag?extends?SimpleTagSupport，which?three?steps?are?necessary?to?implement?the?taghandler?for?the?highlight?tag？（）A、Add?a?doTag?methodB、Add?a?doStartTag?methodC、Add?a?getter?and?setter?for?the?color?attributeD、Create?and?implement?a?TagExtraInfo?classE、Implement?the?DynamicAttributes?interfaceF、Add?a?getter?and?setter?for?the?word1?and?word2?attributes63.CLASSPATH中的“．”的含義是哪項(xiàng)？（）????A、省略號B、當(dāng)前目錄C、所有目錄D、上級目錄64.String?a?=?null；? a.concat（“abc”）；? a.concat（“def”）；? System.out.println（a）；?? What?is?the?result？（）??A、?abcB、?nullC、?abcdefD、?Compilation?fails.E、?The?code?runs?with?no?output.F、?An?exception?is?thrown?at?runtime.65.程序員想要?jiǎng)?chuàng)建一個(gè)名為MyThread的類以便在main方法中用Thread實(shí)例化。對于下面三行：? MyThread必須繼承Thread。????? MyThread必須實(shí)現(xiàn)Thread。? MyThread必須覆蓋public?void?run（）。 有幾行是正確的（）?A、?0B、?1C、?2D、?366.A?web?application?contains?a?tag?file?called?beta.tag?in?/WEB-INF/tags/alpha.?A?JSP?page?called?sort.jspexists?in?the?web?application?and?contains?only?this?JSP?code： 1. 3. The?sort.jsp?page?is?requested. Which?two?are?true？（）A、Tag?files?can?only?be?accessed?using?a?tagdir?attribute.B、The?sort.jsp?page?translates?successfully?and?invokes?the?tag?defined?by?beta.tag.C、The?sort.jsp?page?produces?a?translation?error?because?a?taglib?directive?must?always?have?a?uriattribute.D、Tag?files?can?only?be?placed?in?/WEB-INF/tags，?and?NOT?in?any?subdirectories?of?/WEB-?INF/tags.E、The?tagdir?attribute?in?line?2?can?be?replaced?by?a?uri?attribute?if?a?TLD?referring?to?beta.tag?is?createdand?added?to?the?web?application.67.以下變量類型中，不屬于簡單變量類型的是（）A、一串字符串；B、一個(gè)邏輯值；C、一個(gè)字符；D、雙精度浮點(diǎn)數(shù)；68.interface?Altitude?{? //insert?code?here?? }?? 和4個(gè)聲明：?? int?HIGH?=?7；? public?int?HIGH?=?7；??? abstract?int?HIGH?=?7；?? interface?int?HIGH?=?7；? 分別插入到第2行，有多少行可以編譯？（）??A、?0B、?1C、?2D、?3E、?469.class?BaseClass{?? private?float?x=?1.0f；?? protected?void?setVar?（float?f）?{x?=?f；}?? }?? class?SubClass?exyends?BaseClass?{?? private?float?x?=?2.0f；?? //insert?code?here??8.?}?? Which?two?are?valid?examples?of?method?overriding？（）A、?Void?setVar（float?f）?{x?=?f；}B、?Public?void?setVar（int?f）?{x?=?f；}C、?Public?void?setVar（float?f）?{x?=?f；}D、?Public?double?setVar（float?f）?{x?=?f；}E、?Public?final?void?setVar（float?f）?{x?=?f；}F、?Protected?float?setVar（）?{x=3.0f；?return?3.0f；?}70.55.int[]x={1，2，3，4，5}； 56.inty[]=x； 57.System.out.println（y[2]）； Whichistrue？（） A、Line57willprintthevalue2.B、Line57willprintthevalue3.C、Compilationwillfailbecauseofanerrorinline55.D、Compilationwillfailbecauseofanerrorinline56.71.publicclassYippee2{ staticpublicvoidmain（String[]yahoo）{ for（intx=1；xA、abB、bcC、abcD、Compilationfails.E、Anexceptionisthrownatruntime.72.A?programmer?iterates?over?the?TreeSet?and?prints?the?name?of?each?Drink?object.??What?is?the?result？（） A、TeaB、CoffeeC、Coffee?TeaD、Compilation?fails.E、The?code?runs?with?no?output.F、An?exception?is?thrown?at?runtime.73.現(xiàn)有：?? 1.?class?Book?{?? 2.?private?final?void?read（）?{?System.out.print（"book?"）；?}?? 3.?}?? 4.?class?Page?extends?Book?{?? 5.?public?static?void?main（String?[]?args）?{?? 6.?//?insert?code?here?? 7.?}?? 8.?private?final?void?read（）?{?System.out.print（"page?"）；?}?? 9.?}?? 和如下三個(gè)代碼片段（?x，?y，?z?）：?? x.?//?just?a?comment?? y.?new?Page（）.read（）；? z.?new?Book（）.read（）；?? 分別插入到第6行，有幾個(gè)允許代碼通過編譯并可以運(yùn)行且無異常？（）?A、?0B、?1C、?2D、?374.在正方體上任取三個(gè)頂點(diǎn)連成三角形，則所得的三角形是直角非等腰三角形的概率為（）。A、1/14B、4/7C、2/7D、3/775.以下哪些包是Java標(biāo)準(zhǔn)庫中常用的包？（）???A、java.langB、javax.servlet?.httpC、j?ava.?ioD、java.sql76.public?class?Test?{? public?static?void?main（String?Args[]）?{? int?i?=1，?j?=?0；? switch（i）?{? case?2：?j?+=6；? case?4：?j?+=1；? default：?j?+=2；? case?0：?j?+=4；? }? System.out.println（“j?=”?+j）；? }? }? What?is?the?result？?（）?A、?0B、?2C、?4D、?6E、?9F、?1377.Click?the?’Select?and?Place’?button. Place?the?events?in?the?order?they?occur. 78. A?session-scoped?attribute，?product，?is?stored?by?a?servlet.?That?servlet?then?forwards?to?a?JSP?page.?This?attribute?holds?an?instance?of?the?com.Company.?? Product?class?with?a?name?property?of?“The?Matrix”?and?price?property?of?39.95.?Given?the?JSP?page?code?snippet： What?is?the?response?output?of?this?JSP?page?code?snippet？?（）A、?Default?costs?0.0B、?Default?costs?49.95C、?Default?costs?39.95D、?The?Matrix?costs?0.0E、?The?Matrix?costs?49.95F、?The?Matrix?costs?39.9579.請談?wù)剬ibernate的理解，并簡要敘述Hibernate的一級緩存和二級緩存。80.A?developer?has?created?a?special?servlet?that?is?responsible?for?generating?XML?content?that?is?sent?to?adata?warehousing?subsystem.?This?subsystem?uses?HTTP?to?request?these?large?data?files，?which?arecompressed?by?the?servlet?to?save?internal?network?bandwidth.?The?developer?has?received?a?request?frommanagement?to?create?several?more?of?these?data?warehousing?servlets.?The?developer?is?about?to?copyand?paste?the?compression?code?into?each?new?servlet. Which?design?pattern?can?consolidate?thiscompression?code?to?be?used?by?all?of?the?data?warehousing?servlets？（）A、FacadeB、View?HelperC、Transfer?ObjectD、Intercepting?FilterE、Composite?Facade81.Float?pi?=?new?Float（3.14f）；? if（pi>3）?{? System.out.print（”pi?is?bigger?than?3.?“）；? }? else?{? System.out.print（”pi?is?not?bigger?than?3.?“）； }? finally?{? System.out.println（”Have?a?nice?day.”）；? }? What?is?the?result？（）?A、?Compilation?fails.B、?pi?is?bigger?than?3.C、?An?exception?occurs?at?runtime.D、?pi?is?bigger?than?3.?Have?a?nice?day.E、?pi?is?not?bigger?than?3.?Have?a?nice?day.82.package?foo；? import?java.util.Vector； private?class?MyVector?extends?Vector?{? int?i?=?1；? public?MyVector（）?{? i?=?2； } }? public?class?MyNewVector?extends?MyVector?{? public?MyNewVector（）?{? i?=?4；? }? public?static?void?main（String?args[]）?{? MyVector?v?=?new?MyNewVector（）；? }? }? What?is?the?result？（）A、?Compilation?succeeds.B、?Compilation?fails?because?of?an?error?at?line?5.C、?Compilation?fails?because?of?an?error?at?line?6.D、?Compilation?fails?because?of?an?error?at?line?14.E、?Compilation?fails?because?of?an?error?at?line?17.83.Which?statement?is?true？（） A、The?equals?method?does?NOT?properly?override?the?Object.equals?method.B、Compilation?fails?because?the?private?attribute??cannot?be?accessed?in?line?5.C、To?work?correctly?with?hash-based?data?structures，?this?class?must?also?implement?the?hashCode?method.D、When?adding?Person?objects?to?a?java.util.Set?collection，?the?equals?method?in?line?4?will?prevent?duplicates.84.What?will?be?written?to?the?standard?output?when?the?following?program?is?run？（）? public?class?Qd803?{?? public?static?void?main（String?args[]）?{?? String?word?=?"restructure"；?? System.out.println（word.substring（2，?3））；?? }?? }??A、estB、esC、strD、stE、s85.建立Sochet類的服務(wù)器端需要哪些步驟？（）A、服務(wù)器端對任意指定的IP地址和端口號進(jìn)行監(jiān)聽B、監(jiān)聽端口，等待客戶端的連接C、建立一個(gè)服務(wù)器端對象，提供監(jiān)聽的端口號D、當(dāng)獲得其它客戶端的連接后，停止監(jiān)聽，創(chuàng)建一個(gè)Socket類，用于通訊E、服務(wù)器端在此端口繼續(xù)進(jìn)行監(jiān)聽86.public?class?MethodOver?{? private?int?x，?y；? private?float?z；? public?void?setVar（int?a，?int?b，?float?c）{? x?=?a；? y?=?b；? z?=?c；? }? }?? Which?two?overload?the?setVar?method？（）???A、??void?setVar?（int?a，?int?b，?float?c）{?x?=?a；?y?=?b；?z?=?c；?}B、?public?void?setVar（int?a，?float?c，?int?b）?{?setVar（a，?b，?c）；?}C、?public?void?setVar（int?a，?float?c，?int?b）?{?this（a，?b，?c）；?}D、?public?void?setVar（int?a，?float?b）{?x?=?a；?z?=?b；?}E、?public?void?setVar（int?ax，?int?by，?float?cz）?{?x?=?ax；?y?=?by；?z?=?cz；?}87.public?class?OuterClass?{? private?double?d1??1.0；? //insert?code?here?? }?? You?need?to?insert?an?inner?class?declaration?at?line2.?Which?two?inner?class?declarations?are?valid？（）?A、?static?class?InnerOne?{??public?double?methoda（）?{return?d1；}??}B、?static?class?InnerOne?{??static?double?methoda（）?{return?d1；}?}C、?private?class?InnerOne?{??public?double?methoda（）?{return?d1；}?}D、?protected?class?InnerOne?{??static?double?methoda（）?{return?d1；}?}E、?public?abstract?class?InnerOne?{??public?abstract?double?methoda（）；??}88.Which?will?declare?a?method?that?forces?a?subclass?to?implement?it？（）?A、?Public?double?methoda（）；B、?Static?void?methoda?（double?d1）?{}C、?Public?native?double?methoda（）；D、?Abstract?public?void?methoda（）；E、?Protected?void?methoda?（double?d1）{}89.1.?class?TestA?{? 2.?TestB?b；? 3.?TestA（）?{? 4.?b?=?new?TestB（this）；? 5.?}? 6.?}? 7.?class?TestB?{? 8.?TestA?a；? 9.?TestB（TestA?a）?{? 10.?this.a?=?a；? 11.?}? 12.?}? 13.?class?TestAll?{? 14.?public?static?void?main?（String?args[]）?{? 15.?new?TestAll（）.makeThings（）； 16.?//?...code?continues?on? 17.?}? 18.?void?makeThings（）?{? 19.?TestA?test?=?new?TestA（）； 20.?}? 21.?}? Which?two?statements?are?true?after?line?15，?before?main?completes？（）A、?Line?15?causes?a?stack?overflow.B、?An?exception?is?thrown?at?runtime.C、?The?object?referenced?by?a?is?eligible?for?garbage?collection.D、?The?object?referenced?by?b?is?eligible?for?garbage?collection.E、?The?object?referenced?by?a?is?not?eligible?for?garbage?collection.F、?The?object?referenced?by?b?is?not?eligible?for?garbage?collection.90.public?class?Base?{? public?static?final?String?FOO?=?“foo”；? public?static?void?main（String[]?args）?{? Base?b?=?new?Base（）；? Sub?s?=?new?Sub（）；? 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）；? }?}? class?Sub?extends?Base?{public?static?final?String?FOO=bar；}? What?is?the?result？（）?A、?foofoofoofoofooB、?foobarfoobarbarC、?foobarfoofoofooD、?foobarfoobarfooE、?barbarbarbarbarF、?foofoofoobarbarG、?foofoofoobarfoo91.Which?JSTL?code?snippet?can?be?used?to?perform?URL?rewriting？（）A、’?/>B、’?/>C、’?/>D、’?/>92.What?is?the?result？（） A、0，?0，?0B、150，?60，?0C、Compilation?fails.D、150，?150，?150E、An?exception?is?thrown?at?runtime.93.為將數(shù)組myArray的長度由6改為10，現(xiàn)采取以下編碼：? int[]?myArray?=?new?int[6]；?? myArray?=?new?int[10]；?（覆蓋）?? 代碼執(zhí)行后，以下敘述哪項(xiàng)是正確的？（）??A、?數(shù)組myArray的長度已由6改為10，其中前6個(gè)元素的值不變，后四個(gè)元素的值為空。B、?數(shù)組myArray的長度已由6改為10，其中前6個(gè)元素的值不變，后四個(gè)元素需再經(jīng)過初始化后才能使用。C、?數(shù)組myArray的長度已由6改為10，原來6個(gè)元素的值全部丟失。D、?數(shù)組myArray的長度沒有變化。94.public?class?Drink?implements?Comparable?{? public?String?name；? public?int?compareTo（Object?o）?{? return?0；? }? }? and：? Drink?one?=?new?Drink（）；? Drink?two?=?new?Drink（）；? =?“Coffee”；? =?“Tea”；? TreeSet?set?=?new?TreeSet（）；? set.add（one）；? set.add（two）；? A?programmer?iterates?over?the?TreeSet?and?prints?the?name?of?each?Drink?object.?What?is?the?result？（）?A、?TeaB、?CoffeeC、?Coffee