基于SSH的体育用品销售管理系统-外文翻译

外文原文One:AjaxforJavadevelopers:JavaobjectserializationforAjaxIfyouredoingJavaWebdevelopmentusingAsynchronousJavaScriptandXML(Ajax),thendeliveringdatafromtheservertotheclientisprobablyyourtopconcern.InthissecondarticleintheAjaxforJavadevelopersseries,PhilipMcCarthywalksyouthroughfiveapproachestoJavaobjectserializationandgivesyoualltheinformationyouneedtochoosethedataformatandtechnologybestsuitedtoyourapplication.Inthefirstarticlinthisseries,IintroducedyoutothebuildingblocksofAjax:(1)、HowtouseaJavaScriptXMLHttpRequestobjecttosendanasynchronousrequesttoaserverfromaWebpage(2)、HowtohandleandrespondtothatrequestwithaJavaservletreturninganXMLdocumenttotheclient(3)、HowtousethatresponsedocumentontheclienttoupdateyourpageviewThistime,IllcontinuediscussingthedevelopmentfundamentalsofAjax,butImfocusingonwhatmattersmostformanyJavaWebdevelopers:producingdatafortheclient.MostJavadevelopershaveappliedtheModel-View-Controller(MVC)patterntotheirWebapplications.InatraditionalWebapplication,theviewcomponentiscomposedofJSPs,orperhapsanotherpresentationtechnologysuchasVelocitytemplates.ThesepresentationcomponentsupdatetheuserinterfacebydynamicallyproducingawholenewpageofHTMLtoreplacewhattheuserwaspreviouslylookingat.InthecaseofaJavaWebapplicationwithanAjaxUI,however,theJavaScriptclientcodehasultimateresponsibilityforupdatingwhattheusersees,basedondatareceivedinresponsetoanXMLHttpRequest.Fromtheperspectiveoftheserver,theviewbecomesthedatarepresentationitsendsinresponsetoclientrequests.ProducingXMLfromJavaclassesThereareplentyofreasonstodeliverAjaxresponsesasXML:everyAjax-capablebrowserhasmethodsfornavigatingXMLdocuments,andtherearemanyserver-sidetechnologiesforworkingwithXMLdata.ItseasytodefinethecontractbetweenyourAjaxclientandserverbyproducingaschematodescribethetypesofdocumentsthatwillbeexchanged,andifyoutakeaservice-orientedapproachtoyourserver-sidearchitecture,usingXMLallowsnon-Ajaxclientstoconsumeyourdatafeedsaswell.IllconsiderthreeofthewaysyoucanproduceXMLdatafromyourJavaobjectsanddiscusstheprosandconsofeach.Roll-your-ownserializationFirstofall,youcouldgenerateXMLprogramaticallyfromyourobjectgraph.ThisapproachcanbeassimpleasimplementingatoXml()methodineachofyourJavaBeanclasses.YouwouldthenpickasuitableXMLAPIandhaveeachbeanemitelementstorepresentitsstateandrecursivelycalldowntheobjectgraphtoitsmembers.Clearly,thisapproachdoesntscalewelltoalargenumberofclassesbecauseeachoneneedstohaveitsownXML-generatingcodespeciallywritten.Ontheupside,itsasimpleapproachtoimplement,theresnooverheadintermsofextraconfigurationoramore-complexbuildprocess,andanygraphcomposedofyourJavaBeanscanbeturnedintoanXMLdocumentwithacoupleofcalls.XMLbindingframeworksInrecentyears,severalJavaAPIshavebeendevelopedtosimplifytheprocessofbindingXMLdocumentstoJavaobjectgraphrepresentations.MostprovidebothXMLmarshalingandunmarshaling;thatis,theyperformtwo-wayconversionsbetweenJavaobjectgraphsandXML.TheseframeworksencapsulatealltheworkofhandlingXML,meaningthatapplicationcodeonlyhastodealwithplainJavaobjects.Theytendtoprovideusefulancillaryfunctionsaswell,suchasdocumentvalidation.Broadly,theseframeworkstaketwodifferentapproaches:codegenerationandobject-to-XMLmapping.Illexplainboth.Thecode-generationapproachBindingframeworksthatemploycodegenerationincludeXMLBeans,JAXB,Zeus,andJBind.Castorcanalsoemploythistechnique.ThestartingpointforanyoftheseframeworksisanXMLschemathatdescribesthedatatypesofyourdocuments.Usingtoolsprovidedbytheframework,youthengenerateJavaclassesthatrepresenttheseschema-definedtypes.Finally,youwriteyourapplicationusingthesegeneratedclassestorepresentyourmodeldataandserializethemtoXMLthroughsomeconvenientmechanismprovidedbytheframework.ThecodegenerationapproachisagoodoneifyourapplicationemploysalargeXMLgrammar.ThescalingproblemofwritingcustomXML-serializationmethodsacrosstensofclassesvanishes.Ontheotherhand,younolongergettodefineyourownJavaBeans.Theframework-generatedJavaclassestypicallyfollowtheXMLsstructuresveryclosely,whichcanresultinthembeingratherunwieldytocodeagainst.Also,thegeneratedclassesbecomedumbdatacontainersbecauseyoucantgenerallyaddbehaviortothem.Broadlyspeaking,youneedtomakecompromisesinyourapplicationcodetoplaynicelywiththeschema-generatedtypes.Anotherpitfallisthatachangeintheschemacauseschangestothegeneratedclasses,whichinturnhasaknock-oneffecttoanycodeyouvewrittenaroundthem.XMLbindingframeworksofthistypearemostusefulindataunmarshaling(i.e.,consumingXMLdocumentsandconvertingthemintoJavaobjects).Unlessyouhaveahugedatamodelandwouldbenefitfromhavingclassesgeneratedforyou,code-generation-basedframeworksareprobablyoverkillforanAjaxapplication.ThemappingapproachFrameworksthatemploymappingincludeCastorandApacheCommonsBetwixt.Mappingisgenerallyamoreflexibleandlightweightsolutionthancodegeneration.First,youcodeyourJavaBeansasyouusuallywould,includinganybehaviorandwhateverconveniencemethodsyoulike.Then,atruntime,youcallontheframeworksintrospection-basedmarshaler,anditproducesanXMLdocumentbasedonthetypes,names,andvaluesofyourobjectsmembers.Bydefiningmappingfilesforyourclasses,youcanoverridethedefaultbindingstrategyandadvisethemarshalerhowyoudlikeyourclassestoberepresentedinXML.Thisapproachisagoodcompromisebetweenscalabilityandflexibility.YougettowriteyourJavaclassesthewayyoulikethem,andthemarshalersavesyoufromdealingwithXML.However,althoughthemappingdefinitionfilesaresimpletowriteandscalereasonablywell,themappingrulescanonlychangethestandardbindingbehaviorsomuch,andsomedegreeofcouplingbetweenthestructureofyourobjectsandtheirXMLrepresentationwillalwaysremain.Ultimately,youmayhavetocompromiseeitheryourJavarepresentationsoryourXMLformatforthemappingapproachtowork.DatabindingsummaryDennisSosnoskihaswrittenindepthonthesubjectofXMLdatabindingAPIsofboththecode-generationandcode-mappingflavors.IdrecommendhisexcellentarticlesonCastorandonthecode-generationframeworksifyouwanttoinvestigatethisareafurtherOnthewhole,thecode-generationapproachtradesofftoomuchflexibilityandconveniencetobeusefulforthetypicalAjaxapplication.Ontheotherhand,themapping-basedframeworksmayserveyouwell,aslongasyoucantailortheirmappingstrategiesenoughtoproducetheXMLyouwantfromyourobjects.AlloftheXMLbindingAPIsshareamajordrawbackwiththemanualserializationtechnique:thecouplingofmodelandview.BeinglimitedtoasingleXMLrepresentationofeachobjecttypemeansitislikelythattherewillalwaysbesomeredundantdatatravelingacrossthenetwork.Amoreseriousproblemisthattheclientcodecannotobtainaspecializedviewwhenthesituationdemandsitandmayhaveanawkwardtimetryingtodealwiththecompromisedone-size-fits-allviewofagivenobjectgraph.IntraditionalWebapplicationdevelopment,pagetemplatingsystemsareusedtocleanlyseparateviewgenerationfromcontrollerlogicandmodeldata.ItsanapproachthatcanhelpinanAjaxscenarioaswell.Two:MultipleThreadsObjectsprovideawaytodivideaprogramintoindependentsections.Often,youalsoneedtoturnaprogramintoseparate,independentlyrunningsubtasks.Eachoftheseindependentsubtasksiscalledathread,andyouprogramasifeachthreadrunsbyitselfandhastheCPUtoitself.SomeunderlyingmechanismisactuallydividinguptheCPUtimeforyou,butingeneral,youdonthavetothinkaboutit,whichmakesprogrammingwithmultiplethreadsamucheasiertask.Aprocessisaself-containedrunningprogramwithitsownaddressspace.Amultitaskingoperatingsystemiscapableofrunningmorethanoneprocess(program)atatime,whilemakingitlooklikeeachoneischuggingalongonitsown,byperiodicallyprovidingCPUcyclestoeachprocess.Athreadisasinglesequentialflowofcontrolwithinaprocess.Asingleprocesscanthushavemultipleconcurrentlyexecutingthreads.Therearemanypossibleusesformultithreading,butingeneral,youllhavesomepartofyourprogramtiedtoaparticulareventorresource,andyoudontwanttohanguptherestofyourprogrambecauseofthat.Soyoucreateathreadassociatedwiththateventorresourceandletitrunindependentlyofthemainprogram.Agoodexampleisa“quit”buttonyoudontwanttobeforcedtopollthequitbuttonineverypieceofcodeyouwriteinyourprogramandyetyouwantthequitbuttontoberesponsive,asifyouwerecheckingitregularly.Infact,oneofthemostimmediatelycompellingreasonsformultithreadingistoproducearesponsiveuserinterface.InheritingfromThreadThesimplestwaytocreateathreadistoinheritfromclassThread,whichhasallthewiringnecessarytocreateandrunthreads.ThemostimportantmethodforThreadisrun(),whichyoumustoverridetomakethethreaddoyourbidding.Thus,run()isthecodethatwillbeexecuted“simultaneously”withtheotherthreadsinaprogram.Thefollowingexamplecreatesanynumberofthreadsthatitkeepstrackofbyassigningeachthreadauniquenumber,generatedwithastaticvariable.TheThreadsrun()methodisoverriddentocountdowneachtimeitpassesthroughitsloopandtofinishwhenthecountiszero(atthepointwhenrun()returns,thethreadisterminated)./:c14:SimpleThread.java/VerysimpleThreadingexample.publicclassSimpleThreadextendsThreadprivateintcountDown=5;privatestaticintthreadCount=0;privateintthreadNumber=+threadCount;publicSimpleThread()System.out.println(Making+threadNumber);publicvoidrun()while(true)System.out.println(Thread+threadNumber+(+countDown+);if(-countDown=0)return;publicstaticvoidmain(Stringargs)for(inti=0;i5;i+)newSimpleThread().start();System.out.println(AllThreadsStarted);Arun()methodvirtuallyalwayshassomekindofloopthatcontinuesuntilthethreadisnolongernecessary,soyoumustestablishtheconditiononwhichtobreakoutofthisloop(or,inthecaseabove,simplyreturnfromrun().Often,run()iscastintheformofaninfiniteloop,whichmeansthat,barringsomeexternalfactorthatcausesrun()toterminate,itwillcontinueforever.Inmain()youcanseeanumberofthreadsbeingcreatedandrun.Thestart()methodintheThreadclassperformsspecialinitializationforthethreadandthencallsrun().Sothestepsare:theconstructoriscalledtobuildtheobject,thenstart()configuresthethreadandcallsrun().Ifyoudontcallstart()(whichyoucandointheconstructor,ifthatsappropriate)thethreadwillneverbestarted.SharinglimitedresourcesYoucanthinkofasingle-threadedprogramasonelonelyentitymovingaroundthroughyourproblemspaceanddoingonethingatatime.Becausetheresonlyoneentity,youneverhavetothinkabouttheproblemoftwoentitiestryingtousethesameresourceatthesametime,liketwopeopletryingtoparkinthesamespace,walkthroughadooratthesametime,oreventalkatthesametime.Withmultithreading,thingsarentlonelyanymore,butyounowhavethepossibilityoftwoormorethreadstryingtousethesamelimitedresourceatonce.Collidingoveraresourcemustbepreventedorelseyoullhavetwothreadstryingtoaccessthesamebankaccountatthesametime,printtothesameprinter,oradjustthesamevalve,etc.ImproperlyaccessingresourcesConsideravariationonthecountersthathavebeenusedsofarinthischapter.Inthefollowingexample,eachthreadcontainstwocountersthatareincrementedanddisplayedinsiderun().Inaddition,theresanotherthreadofclassWatcherthatiswatchingthecounterstoseeiftheyrealwaysequivalent.Thisseemslikeaneedlessactivity,sincelookingatthecodeitappearsobviousthatthecounterswillalwaysbethesame.Butthatswherethesurprisecomesin.HowJavasharesresourcesJavahasbuilt-insupporttopreventcollisionsoveronekindofresource:thememoryinanobject.Sinceyoutypicallymakethedataelementsofaclassprivateandaccessthatmemoryonlythroughmethods,youcanpreventcollisionsbymakingaparticularmethodsynchronized.Onlyonethreadatatimecancallasynchronizedmethodforaparticularobject(althoughthatthreadcancallmorethanoneoftheobjectssynchronizedmethods).Herearesimplesynchronizedmethods:synchronizedvoidf()/*.*/synchronizedvoidg()/*.*/Eachobjectcontainsasinglelock(alsocalledamonitor)thatisautomaticallypartoftheobject(youdonthavetowriteanyspecialcode).Whenyoucallanysynchronizedmethod,thatobjectislockedandnoothersynchronizedmethodofthatobjectcanbecalleduntilthefirstonefinishesandreleasesthelock.Intheexampleabove,iff()iscalledforanobject,g()cannotbecalledforthesameobjectuntilf()iscompletedandreleasesthelock.Thus,theresasinglelockthatssharedbyallthesynchronizedmethodsofaparticularobject,andthislockpreventscommonmemoryfrombeingwrittenbymorethanonemethodatatime(i.e.,morethanonethreadatatime).Theresalsoasinglelockperclass(aspartoftheClassobjectfortheclass),sothatsynchronizedstaticmethodscanlockeachotheroutfromsimultaneousaccessofstaticdataonaclass-widebasis.Notethatifyouwanttoguardsomeotherresourcefromsimultaneousaccessbymultiplethreads,youcandosobyforcingaccesstothatresourcethroughsynchronizedmethods.BlockingAthreadcanbeinanyoneoffourstates:New:Thethreadobjecthasbeencreatedbutithasntbeenstartedyetsoitcannotrun.Runnable:Thismeansthatathreadcanberunwhenthetime-slicingmechanismhasCPUcyclesavailableforthethread.Thus,thethreadmightormightnotberunning,buttheresnothingtopreventitfrombeingruniftheschedulercanarrangeit;itsnotdeadorblocked.Dead:Thenormalwayforathreadtodieisbyreturningfromitsrun()method.Youcanalsocallstop(),butthisthrowsanexceptionthatsasubclassofError(whichmeansyouarentforcedtoputthecallinatryblock).Rememberthatthrowinganexceptionshouldbeaspecialeventandnotpartofnormalprogramexecution;thustheuseofstop()isdeprecatedinJava2.Theresalsoadestroy()method(whichhasneverbeenimplemented)thatyoushouldnevercallifyoucanavoiditsinceitsdrasticanddoesntreleaseobjectlocks.Blocked:Thethreadcouldberunbuttheressomethingthatpreventsit.WhileathreadisintheblockedstatetheschedulerwillsimplyskipoveritandnotgiveitanyCPUtime.Untilathreadreenterstherunnablestateitwontperformanyoperations.BecomingblockedTheblockedstateisthemostinterestingone,andisworthfurtherexamination.Athreadcanbecomeblockedforfivereasons:Youveputthethreadtosleepbycallingsleep(milliseconds),inwhichcaseitwillnotberunforthespecifiedtime.Youvesuspendedtheexecutionofthethreadwithsuspend().Itwillnotbecomerunnableagainuntilthethreadgetstheresume()message(thesearedeprecatedinJava2,andwillbeexaminedfurther).Youvesuspendedtheexecutionofthethreadwithwait().Itwillnotbecomerunnableagainuntilthethreadgetsthenotify()ornotifyAll()message.(Yes,thislooksjustlikenumber2,buttheresadistinctdifferencethatwillberevealed.)ThethreadiswaitingforsomeI/Otocomplete.Thethreadistryingtocallasynchronizedmethodonanotherobject,andthatobjectslockisnotavailable.Youcanalsocallyield()(amethodoftheThreadclass)tovoluntarilygiveuptheCPUsothatotherthreadscanrun.However,thesamethinghappensiftheschedulerdecidesthatyourthreadhashadenoughtimeandjumpstoanotherthread.Thatis,nothingpreventstheschedulerfrommovingyourthreadandgivingtimetosomeotherthread.Whenathreadisblocked,theressomereasonthatitcannotcontinuerunning.中文翻译（一）面向Java开发人员的Ajax:Ajax的Java对象序列化如果您正在使用异步JavaScript和XML（Ajax）进行JavaWeb开发，那么您最关心的问题可能就是把数据从服务器传递给客户机。在面向Java开发人员的Ajax系列的第二篇文章中，PhilipMcCarthy介绍了Java对象序列化的五种方式，并提供了选择最适合应用程序的数据格式和技术所需要的全部信息。下面介绍Ajax的构造块：(1)如何用JavaScriptXMLHttpRequest对象从Web页面向服务器发送异步请求。(2)如何用Javaservlet处理和响应请求（向客户机返回XML文档）。(3)如何在客户端用响应文档更新页面视图。这一次，我将讨论Ajax开发的基础知识，但是将侧重于许多JavaWeb开发人员最关心的问题：为客户机生成数据。多数Java开发人员已经把模型-视图-控制器（MVC）模式应用在他们的Web应用程序上。在传统的Web应用程序中，视图组件由JSP或者其他表示技术（例如Velocity模板）构成。这些表示组件动态地生成全新的HTML页面，替代用户以前正在查看的页面，从而更新用户界面。但是，在JavaWeb应用程序使用AjaxUI的情况下，基于从XMLHttpRequest的响应接收到的数据，JavaScript客户端代码对于更新用户看到的内容负有最终责任。从服务器的角度来看，视图成为它响应客户机请求而发送的数据表示。从Java类产生XML把Ajax响应作为XML来传递有许多原因：每个支持Ajax的浏览器都有导航XML文档的方法，也有许多服务器端技术可以处理XML数据。通过制定一个方案，描述要交换的文档类型，在Ajax客户端和服务器端之间很容易定义合约，而且如果服务器端架构采用面向服务的方式，那么使用XML也可以允许非Ajax客户机使用您提供的数据。自行进行序列化首先，可以从对象图以编程的方式生成XML。这种方式可以简单到只是在每个JavaBean类中实现toXml()方法即可。然后就可以选择合适的XMLAPI，让每个bean提供表示自己状态的元素，并递归地对自己的成员调用对象图。显然，这种方式无法扩展到大量的类，因为每个类都需要专门编写自己的XML生成代码。从好的方面来看，这是一个实现起来简单的方式，没有额外的配置支出或者更复杂的构建过程支出，任何JavaBean图都可以只用几个调用就变成XML文档。XML绑定框架近些年来，已经开发了多个JavaAPI来简化XML文档到Java对象图的绑定过程。多数都提供了XML编排和拆解；也就是说，它们可以在Java对象图和XML之间执行双向会话。这些框架封装了XML处理的全部工作，这意味着应用程序代码只需要处理普通的Java类。它们还希望提供有用的辅助功能，例如文档验证。笼统来说，这些框架采用了两种不同的方式：代码生成和对象到XML映射。我将分别解释这两种方式。代码生成方式使用代码生成的框架包括XMLBeans、JAXB、Zeus和JBind。Castor也能使用这项技术。这类框架的起点是描述文档数据类型的XML方案。使用框架提供的工具，就可以生成代表这些方案定义类型的Java类。最后，用这些生成的类编写应用程序，表示自己的模型数据，并通过框架提供的一些辅助机制把数据序列化成XML。如果应用程序要使用大型XML语法，那么代码生成方式是个很好的方法。在数十个类上编写定制XML序列化代码的可伸缩性问题由此消除。另一方面，也不再需要定义自己的JavaBean。框架生成的Java类通常非常符合XML的结构，所以对它们进行编码很难。而且，生成的类变成哑数据容器，因为一般不能向它们添加行为。一般来说，在应用程序代码中要做些妥协，才能很好地处理方案生成的类型。另一个缺陷是如果修改方案，会造成生成的类也要修改，所以也就会对围绕它们编写的代码带来相应的影响。这种类型的XML绑定框架在数据拆解时最有用（例如，使用XML文档并把它们转化成Java对象）。除非拥有大型数据模型而且有可能从生成的类中获益，否则基于代码生成的框架对于Ajax应用程序来说可能有很大的杀伤力。映射方式采用映射方式的框架包括Castor和ApacheCommonsBetwixt。映射通常是比代码生成更灵活和更轻量的解决方案。首先，可以像通常一样编写JavaBean，包括任何行为以及任何自己喜欢的方便的方法。然后，在运行时，调用框架中基于内省的编排器，并根据对象成员的类型、名称和值生成XML文档。通过定义类的映射文件，可以覆盖默认的绑定策略，并就类在XML中的表示方式对编排器提出建议。这种方法是在可伸缩性与灵活性之间的良好折中。可以按照自己喜欢的方式编写Java类，编排器负责处理XML。虽然映射定义文件编写起来简单，可伸缩性也足够好，但是映射规则最多只能改变标准的绑定行为，而且在对象结构和它们的XML表示之间总要残留一些耦合。最终，可能不得不在Java表示或XML格式之间任选一个做些折中，才能让映射方法起作用。数据绑定总结DennisSosnoski就XML数据绑定API的主题，在代码生成和代码映射两个方面写了深入的文章。如果想进一步研究这个领域，我推荐他在Castor和代码生成框架方面的精彩文章。总之，代码生成方式损失了过多的灵活性和方便性，对于典型的Ajax应用程序用处不大。另一方面，基于映射的框架可能工作得很好，但是要恰到好处地调整它们的映射策略，以便从对象生成需要的XML。所有的XML绑定API都具有手工序列化技术的一个主要不足：模型和视图的耦合。被限制为一个类型一个XML表示，就意味着在网络上总要有冗余数据传输。更严重的问题是，在情况要求客户端代码使用专门视图时，客户端代码却无法得到它，所以可能要费力地处理给定对象图的一成不变的视图。在传统的Web应用程序开发中，采用页面模板系统把视图生成与控制器逻辑和模型数据干净地分离。这种方法在Ajax场景中也会有帮助。(二)多线程利用对象，可将一个程序分割成相互独立的区域。我们通常也需要将一个程序转换成多个独立运行的子任务。像这样的每个子任务都叫作一个“线程”（Thread）。编写程序时，可将每个线程都想象成独立运行，而且都有自己的专用CPU。一些基础机制实际会为我们自动分割CPU的时间。我们通常不必关心这些细节问题，所以多线程的代码编写是相当简便的。这时理解一些定义对以后的学习狠有帮助。“进程”是指一种“自包容”的运行程序，有自己的地址空间。“多任务”操作系统能同时运行多个进程（程序）但实际是由于CPU分时机制的作用，使每个进程都能循环获得自己的CPU时间片。但由于轮换速度非常快，使得所有程序好象是在“同时”运行一样。“线程”是进程内部单一的一个顺序控制流。因此，一个进程可能容纳了多个同时执行的线程。多线程的应用范围很广。但在一般情况下，程序的一些部分同特定的事件或资源联系在一起，同时又不想为它而暂停程序其他部分的执行。这样一来，就可考虑创建一个线程，令其与那个事件或资源关联到一起，并让它独立于主程序运行。一个很好的例子便是“Quit”或“退出”按钮我们并不希望在程序的每一部分代码中都轮询这个按钮，同时又希望该按钮能及时地作出响应（使程序看起来似乎经常都在轮询它）。事实上，多线程最主要的一个用途就是构建一个“反应灵敏”的用户界面。从线程继承为创建一个线程，最简单的方法就是从Thread类继承。这个类包含了创建和运行线程所需的一切东西。Thread最重要的方法是run()。但为了使用run()，必须对其进行过载或者覆盖，使其能充分按自己的吩咐行事。因此，run()属于那些会与程序中的其他线程“并发”或“同时”执行的代码。下面这个例子可创建任意数量的线程，并通过为每个线程分配一个独一无二的编号（由一个静态变量产生），从而对不同的线程进行跟踪。Thread的run()方法在这里得到了覆盖，每通过一次循环，计数就减1计数为0时则完成循环（此时一旦返回run()，线程就中止运行）。/:SimpleThread.java/VerysimpleThreadingexamplepublicclassSimpleThreadextendsThreadprivateintcountDown=5;privateintthreadNumber;privatestaticintthreadCount=0;publicSimpleThread()threadNumber=+threadCount;System.out.println(Making+threadNumber);publicvoidrun()while(true)System.out.println(Thread+threadNumber+(+co