java基础、等综合练习面试题

1:WhichstatementsaboutJavacodesecurityarenot Thebytecodeverifierloadsallclassesneededfortheexecutionofaprogram.B.Executingcodeisperformedbytheruntimeinterpreter.Atruntimethebytecodesareloaded,checkedandruninanTheclassloaderaddssecuritybyseparatingthenamespacesfortheclassesofthelocalfilesystemfromthoseimportedfromnetworksources.DPublicclasspublicstaticvoidmain(Stringargs[]){Staticintx[]=newint[15];}}Whencompile,someerrorwillWhenrun,someerrorwillOutputisOutputis Staticintx[]publicstaticvoidmain(String{chardigit=for(inti=0;i<10;{switch{Case'x'{intj=0;}default{intj=100;}}}inti=j;}A.100willbeprinted11Thecodewillnotcompilebecausethevariableicannotbedeclaredtwicewithinthemain()ThecodewillnotcompilebecausethevariablejcannotbedeclaredtwicewithintheswitchNoneofCclassBaseinti=publicvoidamethod(){}}}PublicclassDerivedextendsBase{inti=-1;publicstaticvoidmain(Stringargv[]){Baseb=newDerived();}Publicvoidamethod(){}}A.Derived.amethod()-1B.Derived.amethod()99piletimeerror()-A.StringBuffersb1=B.Booleanb=newBoolean("abcd");C:byteb=255;D.floatfl=1.2;6:Aclassdesignrequiresthataparticularmembervariablemustbeaccessiblefordirectaccessbyanysubclassesofthisclass.butotherwisenotbyclasseswhicharenotmembersofthesamepackage.Whatshouldbedonetoachievethis?A.ThevariableshouldbemarkedB.ThevariableshouldbemarkedC.ThevariableshouldbemarkedD.Thevariableshouldhavenospecialaccessmodifier7:Usetheoperator“>>”and“>>>”.WhichstatementisA.10100000000000000000000000000000>>4give000010100000000000000000B.10100000000000000000000000000000>>4give111110100000000000000000C.10100000000000000000000000000000>>>4give000000000000000000000000D.10100000000000000000000000000000>>>4give111110100000000000000000Givethefollowingjavasource//pointPublicclass//do}WhichstatementiscorrectlyJavasyntaxatpointGivethefollowingjavasourcefragement://pointxpublicclassInteresting{//dosomething}WhichstatementiscorrectlyJavasyntaxatpointx?A.publicclassMyClass{//dootherB.staticintC.classMyClass{//do9:abint型变量,则执行下述语句组后,b{}while(b--<0);DSystem.out.println(“Test1”);}Elseif(x>9){System.out.println(“Test2”);}else{System.out.println(“TestWhichrangeofvaluexwouldproduceofoutput“TestGivethecodefragment:if(x>4){System.out.println(“Test1”);}elseif(x>9){System.out.println(“Test2”);}else{System.out.println(“Test3”);}Whichrangeofvaluexwouldofoutput“Testpublicvoidcreate()VectormyVect=new4)给出下面的代码片断。。。下面的哪些陈述为错误的?1)publicvoidcreate(){2) VectormyVect;3) myVect=newVector();4)}A.第二行的不会为变量myVect分配内存空间。B.VectorC.VectorD.VectorC12:3个阶段、8个子阶段，以下哪一个是正常的C.设计阶段、编码阶段、阶段D13:WhichcodefragmentswouldcorrectlyidentifythenumberofargumentspassedviacommandlinetoaJavaapplication,excludethenameoftheclassthatisbeinginvoke.A.intcount=B.intcount=args.length- args[count]为null调用equals方出现ThefollowingcodeisentirecontentsofafilecalledExample.java,causespreciselyoneerrorduringcompilation:classSubClassextends}classBaseClass(){Stringstr;public}publicBaseClass(Strings){}}PublicclassExample{publicvoidmethod(){SubClasss=newSubClass(“o”);BaseClassb=newBaseClass(“world”);}}Whichlinewouldbecausetheerror?D15:下述程序代码中有语法错误的行是（ inti,ia[10],ib[10]; for(i=0;i<=9;i++) /*第2行*/ /*第3行*/ /*第4行下述程序代码中有语法错误的行是 ）123416:鉴于Java的特点，它最适合的计算环境D.开放式计算环B17:关于收集的哪些叙述是对的程序开发者必须自己创建一个线程进行内存释放的工作收集将检查并释放不再使用的内存收集允许程序开发者明确指定并立即释放该内存收集能够在期望的时间释放被java对象使用的内存BWhatwillhappenwhenyouattempttocompileandrunthefollowingPublicclassStatic Static{intx=}StaticintPublicstaticvoidmain(Stringargs[]) System.out.println(x+y+}PublicstaticvoidmyMethod() y=x+++++x;}}Whatwillhappenwhenyouattempttocompileandrunthefollowingprints:prints:prints:prints:19:Whichmethodyoudefineasthestartingpointofnewthreadinaclassfromwhichnewthethreadcanbeexcution?publicvoidpublicvoidpublicvoidpublicstaticvoidmain(StringStrings=”ExampleString”;WhichoperationisnotStrings=”ExampleString”;WhichoperationisnotA.inti=s.length();C.StringD.StringB21:lucene的索引使用的什么数据结构22:写一个Hash的函数，或者类23:为什么采用Hibernate的批量删除方法来删除大批量的记录数据时速度特别慢答：在使用Hibernate2.X不推荐Hibernate的批量删除方法来删，Hibernate1Hibernate3.024:设计算法以求解从集合{1..n}k(k<=n)个元素的所有组合。例如，从集合{1..4}中选2个元素的所有组合的输出结果为：12，13，14，2324，34。25:在JSP中如何客户端的请求，如何CGI变量，如何确定某个Jsp文件的真实路客户端的请求：通过HttpServletRequest类的request变量部分来自HTTP请求命令和请求头，例如Content-Length头；部分来自Socket本身，例如主机的名字和IP地址；也有部分与服务器安装配置有关，例如URL到实际路径的映射。获取Jsp文件的真实路径，通过request.getRealPath函数。26:在使用springJ2EE分层结构中,service层一般都有XXXManager接口，请问他的27:描述JSPServlet的区别、共同点、各自应用的范围JSPSERVLET,但是两者的创建方式不一样.ServletJAVA程序代码构成擅长于流程控制和事物处理而通过Servlet来生成页很不直观;JSP由HTM