java工程师考试

1、第一题：（过程可以写在后面）学校的毕业话剧演出由四个小美女来出演小红帽、美羊羊、女巫和公主的角色。没人在排练时的角色与演出时的角色不同。排练时出演小红帽的人会撒谎，通过如下消息，请判断四人在演出和排练时分别出演什么角色。梅:“排练时，兰的角色是演出时竹的角色。”、人.“菊排练时扮演的是美羊羊。”竹:“演出时我演公主。”菊:“兰演出时扮演的是美羊羊。”第二题：解数独题（数独是九宫格（即3格宽x3格高）正方形状，每一格又细分为一个九宫格，在没一个小九宫格中，分别填上19个数字，让每一个大九宫格没一列，没一行的数字都不重复。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"选择：C8、Givertheseclassdefinitions;classSupercla

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

12、blyillegalatruntimeb) Definitelylegalatruntime9、简述以下代码是在做什么事情？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:请从空白处填写代码，满足以下功能：A) 从请求中得到用户名和口令(请求通过web浏览器中的HTML页面提交，页面中用户名对象名为userName,口令对象名为password)如果用户名为”admin”,口令为password,则讲登陆成功，将页面转到loginSuccess.jsp页面，并在sess

14、ion存放用户名(username)和密码(password)C(如果用户名和空灵为其他值，转到error.jspPublicclassTestServletextendsHttpServletPublicvoidservice(HttpServletRequestrequest,HttpServletResponseresopnse)throwsServletException,IOException/IncludefollowinglinsinallservletTry/请在此添写代码If(userName.equals(“admin”)&&password.equals(

15、“password”)request.getsession.”)；.setAttribute("username",adminrequest.getsession.setAttribute("passwordII”",password”);Request.sendRedirect(“loginSuccess.jsp”);elseRequest.sendRedirect（“error.jsp”）;catch（Exceptione）典道的笔试分A-B卷，题型有：1. 选择题30道（每道2分共60分）代码阅读题4道（每道5分共20分）2. 程序逻辑题2道（每道

16、10分共20分）不管是A-B卷，考察的范围都是基础知识，这个是和几个做B卷的同学那了解到的，主要的考点如下：考点名称考试频率难易度备注数组高易值传递与址传递高中Main函数低中线程低难Swing与awt低中Ascii码高难请务必记住常用ascii码，代码题都有考运算符优先级低中去网上百度一下Oop思想高中方法重载与重写高易包低易方法与类的命名规则低易逻辑思维高难其他的记得不是很清楚了，不过不会超过基础知识这个范围，但光靠书(accp6.0)上那些还不够，建议找些参考书学习一下，越基础越好。以下是A卷代码阅读题&建一个数组，顺序输出10位数，然后把这10位数再倒序输出publicclas

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

18、;);9、考的是方法重载，它是将两个方法的参数顺序颠倒了一下，看题的时候要注意。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;输出结果是：56以下是A卷手写代码题：8.请用1、2、3、4组成N个数值不重复且个十百

19、位都不重复的3位数，一共有几个？分别是什么？共有：24个分别是：123,124,132,134,142,143,213,214,231,234,241,243,312,314,321,324,341,342,412,413,421,423,431,432,参考答案：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个，公式：4*3*2=24，具体数学公式请见排列算法9.查询子串在父串中出现的次数：参考答案：设：strl为父串，str2为字串，则:publicclassTest6publicstaticvoidmain(Stringargs)Stringstr1="hdsajkfhuisadhifnokfasdfdasdoksdfsdsfsok"Stringstr2="ok"Stringtemp=""intcount=0;for(temp=str1;temp!