java工程師考試

1、第一題：（過程可以寫在后面）學(xué)校的畢業(yè)話劇演出由四個(gè)小美女來出演小紅帽、美羊羊、女巫和公主的角色。沒人在排練時(shí)的角色與演出時(shí)的角色不同。排練時(shí)出演小紅帽的人會(huì)撒謊，通過如下消息，請(qǐng)判斷四人在演出和排練時(shí)分別出演什么角色。梅:“排練時(shí)，蘭的角色是演出時(shí)竹的角色。”、人.“菊排練時(shí)扮演的是美羊羊?！敝?“演出時(shí)我演公主?！本?“蘭演出時(shí)扮演的是美羊羊?！钡诙}：解數(shù)獨(dú)題（數(shù)獨(dú)是九宮格（即3格寬x3格高）正方形狀，每一格又細(xì)分為一個(gè)九宮格，在沒一個(gè)小九宮格中，分別填上19個(gè)數(shù)字，讓每一個(gè)大九宮格沒一列，沒一行的數(shù)字都不重復(fù)。8174694833852756966511831、Whichlinecon

2、tainsaconstructorinthisclassdefinition?publicclassCounter/(1)intcurrent,step;publicCounter(intstartVaue,intstepValue)/(2)set(startValue);setStepValue(steValue);publicintget()returncurrent;/(3)publicvoidset(intvalue)current=value;/(4)publicvoidsetStepValue(intstepValue)step=stepValue;/(5)Codemarkedwi

3、th(1)isaconstructor1) Codemarkedwith(2)isaconstructorCodemarkedwith(3)isaconstructor2) Codemarkedwith(4)isaconstructorCodemarkedwith(5)isaconstructor2、Aninstancemember.1) isalsocalledastaticmemberisalwaysavariable2) isneveramethodbelongstoasingleinstance,nottotheclassasawhole3) alwaysrepresentsanope

4、ration3、Giventhefollowingclass,whichstatementscanbeinsertedatpositionIwithoutcausingthecodetofailcompilation?publicclassQ6db8inta;intb=0;staticintc;publicvoidm()intd;inte=0;/Position11) a+b+2) c+d+3) e+7、Whatiswrongwiththefollowingcode?ClassMyExceptionextendsException。Publicclassqb4abPublicvoidfoo()

5、TryBar();finallyBaz();catch(MyExceptione)Publicvoidbar()throwsMyExceptionThrownewException();Publicvoidbaz()throwsRuntimeExceptionThrownewRuntimeException();4、)Sincethemethodfoo()doesnotcatchtheexceptiongeneratedbythemethodbaz(),itmustdeclaretheRuntimeExceptioninitsthrowsclause.5、)Athetryblockcannot

6、befollowedbybothacatchandafinallyblock.6、)Anemptycatchblockisnotallowed.7、)Acatchblockcannotfollowafinallyblock.8、)Afinallyblockmustalwaysfollowoneormorecatchblocks.5、WhatwillhappenwhenyouattempttocompileandrunthefollowingprogrambypassingtheTestclasstotheJavainterpreter?ClassTestPublicstaticvoidmain

7、System.out.print(“hello”);Selecttheonerightanswer.6. theprogramdoesnotcompilebecausemain()isnotdefinedcorrectly.7. Theprogramcompilesbutwhenyoutrytoruntheinterpretercompliesthatitcannotfindthemain()methoditneedstorun.C) theprogramcompilesbutyoucannotrunitbecausetheclassisnotdeclaredaspublic.D) thepr

8、ogramcompilesandrunswithoutanerrorbutdoesnotdisplayanythinginthestandardoutput.E) theprogramcompilesanddisplays“hello”inthestandardoutputwhenyouinrunit.6、Givethosecodesnippets:Booleanb1=newBoolean(true);Booleanb2=newBoolean(true);WhichexpressionsarelegalJavaexpressionsthatreturntrue?Selectallvalidan

9、swer.3. b1=b2b1.equals(b2)C) b1&b2b1|b2D) b1&&b2b1|b27、Giventhiscodesnippet:trytryThis();return;catch(IOExceptionx1)System.out.println("exception1");return;catch(Exceptionx2)System.out.println("exception2");return;finallySystem.out.println("finally");Whatwil

10、lappearinthestandardoutputiftryThis()throwsaNumberFormatException?Selecttheonerightanswer.a) Nothing"exception1",followedby"finally"b) "exception2",followedby"finally""exception1"c) "exception2"選擇：C8、Givertheseclassdefinitions;classSupercla

11、ssclassSubclass1extendsSuperclassclassSubclass2extendsSuperclassandtheseobjects;Superclassa=newSuperclass。；Subclasslb=newSubclass1();Subclass2c=newSubclass2();whichofthefollowingexplainstheresultofthestatement;b=(Subclass1)c;Selectedtheonerightanswer;Illegalatcompiletimea) Legalatcompiletimebutpossi

12、blyillegalatruntimeb) Definitelylegalatruntime9、簡(jiǎn)述以下代碼是在做什么事情？Publicstaticjavax.ejb.EJBHomegetEJBHome(StringJNDIName)throwsNameNotFoundException,NamingExceptionjava.util.Hashtableenv=newjava.util.Hashtable(1);NITIAI_CONTEXT_FACTORY,”);Javax.naming.ContextinitContext=newjavax.namingnitalContext(env);

13、If(initContext=null)ThrownewRuntimeException(“getEJBHomecould'tretrieveinitialcontext”);return(javax.ejb.EJBHome)initContext.lookup(JNDIName)；10:請(qǐng)從空白處填寫代碼，滿足以下功能：A) 從請(qǐng)求中得到用戶名和口令(請(qǐng)求通過web瀏覽器中的HTML頁面提交，頁面中用戶名對(duì)象名為userName,口令對(duì)象名為password)如果用戶名為”admin”,口令為password,則講登陸成功，將頁面轉(zhuǎn)到loginSuccess.jsp頁面，并在sess

14、ion存放用戶名(username)和密碼(password)C(如果用戶名和空靈為其他值，轉(zhuǎn)到error.jspPublicclassTestServletextendsHttpServletPublicvoidservice(HttpServletRequestrequest,HttpServletResponseresopnse)throwsServletException,IOException/IncludefollowinglinsinallservletTry/請(qǐng)?jiān)诖颂韺懘aIf(userName.equals(“admin”)&&password.equals(

15、“password”)request.getsession.”)；.setAttribute("username",adminrequest.getsession.setAttribute("passwordII”",password”);Request.sendRedirect(“l(fā)oginSuccess.jsp”);elseRequest.sendRedirect（“error.jsp”）;catch（Exceptione）典道的筆試分A-B卷，題型有：1. 選擇題30道（每道2分共60分）代碼閱讀題4道（每道5分共20分）2. 程序邏輯題2道（每道

16、10分共20分）不管是A-B卷，考察的范圍都是基礎(chǔ)知識(shí)，這個(gè)是和幾個(gè)做B卷的同學(xué)那了解到的，主要的考點(diǎn)如下：考點(diǎn)名稱考試頻率難易度備注數(shù)組高易值傳遞與址傳遞高中Main函數(shù)低中線程低難Swing與awt低中Ascii碼高難請(qǐng)務(wù)必記住常用ascii碼，代碼題都有考運(yùn)算符優(yōu)先級(jí)低中去網(wǎng)上百度一下Oop思想高中方法重載與重寫高易包低易方法與類的命名規(guī)則低易邏輯思維高難其他的記得不是很清楚了，不過不會(huì)超過基礎(chǔ)知識(shí)這個(gè)范圍，但光靠書(accp6.0)上那些還不夠，建議找些參考書學(xué)習(xí)一下，越基礎(chǔ)越好。以下是A卷代碼閱讀題&建一個(gè)數(shù)組，順序輸出10位數(shù)，然后把這10位數(shù)再倒序輸出publicclas

17、sTestpublicstaticvoidmain(Stringargs)intarr=newint1,2,3,4,5,6,7,8,9,10;System.out.println("順序輸出");for(inti=0;i<arr.length;i+)System.out.print(arri+",");System.out.println();System.out.println("倒敘輸出");for(intj=arr.length-1;j>=0;j-)System.out.print(arrj+","

18、;);9、考的是方法重載，它是將兩個(gè)方法的參數(shù)順序顛倒了一下，看題的時(shí)候要注意。3.publicclassTest5publicstaticvoidmain(Stringargs)intarr=newint1,2,3,4,5,6,7,8;a(arr);b(arr);a(arr);staticvoida(intarr)for(inttemp:arr)System.out.println(temp);staticvoidb(intarr)for(inti=0;i<arr.length;i+)arri*=i;輸出結(jié)果是：56以下是A卷手寫代碼題：8.請(qǐng)用1、2、3、4組成N個(gè)數(shù)值不重復(fù)且個(gè)十百

19、位都不重復(fù)的3位數(shù)，一共有幾個(gè)？分別是什么？共有：24個(gè)分別是：123,124,132,134,142,143,213,214,231,234,241,243,312,314,321,324,341,342,412,413,421,423,431,432,參考答案：Intcount=0;For(inti=1;iv=4;i+)For(intj=1;jv=4;j+)For(intk=1;kv=4;k+)lf(i!=j&&i!=k&&j!=k)Count+;System.out.println(i*100+j*10+k);一共有24個(gè)，公式：4*3*2=24，具體數(shù)學(xué)公式請(qǐng)見排列算法9.查詢子串在父串中出現(xiàn)的次數(shù)：參考答案：設(shè)：strl為父串，str2為字串，則:publicclassTest6publicstaticvoidmain(Stringargs)Stringstr1="hdsajkfhuisadhifnokfasdfdasdoksdfsdsfsok"Stringstr2="ok"Stringtemp=""intcount=0;for(temp=str1;temp!