外文翻译 - 基于JavaServer Faces技术的酒店预订系统

0外文原文HotelReservationSystemBasedontheJavaServerFacesTechnologyThispaperdescribesimplementationofaweb-basedhotelreservationsystemwhichenablesuserstobookhotelroomsbymeansofawebbrowser.ThesystemisbasedonJavaServerFacestechnologyinthepresentationlayer,SpringFrameworkintheservicelayerandiBatislibraryforthedataaccesslayer.I.INTRODUCTIONTheHotelReservationSystemisaspecifictypeofsoftwarethatsupports,oftenbymeansofawebbrowser,wholeinfrastructureofthehotelforwhichthesystemhasbeendeployed.Itskeyfeaturesarelistedbelow:Tosearchandtobookhotelrooms.Tonotifyofeveryeventrelatedtoauserbysendingtheemailonagivenaddressduringtheregistrationprocess.Tosupportdefinitionprocessofeachcomponentofthehotel.Thecomponentsofthehotelare:rooms,promotions,packages,discountsandservices.Tocompletethereservationprocessbynotifyingthesystemaboutthefactthattheguestcametothehotelandreceivedkeystothebookedroom.II.JAVASERVERFACESTheusergraphicalinterfaceisacrucialpartofeverycomputerprogrammewithregardtoitsresponsibilityforinteractionwiththeusers.Thispartofapplicationshouldbeflexible,whichmeanssusceptibletoanyneededchangesandwithoutanydoubts,userfriendly.Regrettably,processofdevelopingsuchuserinterfaceinthemainrequiresusuallyaprofusionofdevelopersworkandtime,makingthewholedevelopmentprocessinvolvedandonerous.ThemostaptingtechnologytothisfieldisJavaServerFaces(JSF).Thisholistic,component-basedsolutionforlongstandingproblemsfacingsoftwaredevelopershasaspecificgoal:tomakewebdevelopmentfasterandeasierbymaskingalotofcomplexitieshiddenbehindthiskindofprogramming.JSFtechnologyisaserver-sideuserinterfaceframeworkforJavatechnology-basedwebapplications.ThemaincomponentsofJSF1technologyareasfollows:TwoJavaServerPagescustomtagslibraryforexpressingUIcomponentswithinaJSPpageandforwiringcomponentstoserver-sideobjects.TheuserinterfacecreatedwithJSFtechnology(representedbymyUIontheFig.1)runsontheserverandrendersbacktotheclient(inthiscasethebrowser).Becauseweb-basedapplications,mustoftenappeasemultipleclients(suchasdesktopbrowsers,cellphones,andPDAs),JSFhasapowerfularchitecturefordisplayingcomponentsindifferentways.Asforthebrowsers,forwhichJSFismostlyused,thedefaultrenderingtechnologyisHTML4.0,thoughtheotherslikeWMLorSVGarealsopossible.OneofthegreatestadvantagesofJSFtechnologyisthatitoffersacleanseparationbetweenbehaviorandpresentationlayers.III.SPRINGFRAMEWORKSpringisalightweight,inversionofcontrolcontainer,createdtoaddressthecomplexityofenterpriseapplicationdevelopment.SpringmakespossibletouseplainJavaBeanstoachievethingsthatwerepreviouslyonlypossiblewithEJBs10,11.AnyJavaapplicationcanbenefitfromSpringintermsofsimplicity,test-ability,andloosecoupling.TheSpringFrameworkcontainsalotoffeatures,whicharewell-organizedinsevenmodules.Whentakenasawhole,thesemodulesgiveeverythingthatisneededtodevelopenterpriseapplications,althoughthereisnomusttobuildtheapplicationfullyontheSpringframework.Onecanpickandchooseonlythosemodulesthatsuitbesttotheapplicationandignoretherest.ThisstrategywaschosenfortheHotelReservationSystemSinceoneofthecorevaluepropositionsoftheframeworkisthatofenablingchoicebynotforcingonetoapplyanyparticulararchitecture,technologyormethodology,Springalsoprovidesconvenientmechanismsforintegrationwithnumberofthird-partyframeworks(alsowithJSFandiBatis).IV.APACHEIBATISDATAMAPPERApacheiBatisJDBCbasedDataMapperprovidessimpleandflexiblewaytotransportdatabetweenrelationaldatabaseandJava,.NetorRubyapplication.ContrarytopopularHibernatelibrary,iBatisdoesnotdirectlytieclassestotablesorfieldstocolumns,butinstead,itcouplesobjectswithresultsofstoredproceduresorSQLstatementsusingsimple2XMLdescriptorlettingthedevelopertoreachonlyforrequireddata.TheiBatisframeworkcanmapnearlyanydatabasetoanyobjectmodelandisverytolerantoflegacydesigns,orevenbaddesigns.SimplicityisthemainadvantageoftheiBatisoverotherframeworks.TheHotelReservationSystemwasprimarilybuiltuponJSFtechnologyfortheuserinterfacealongwithauxiliarylibrariesSpringandiBatis.TheapplicationarchitectureispresentedinFig.3.Thecompositionofthesystemismodular.Eachlayerisseparatedwithandappropriateinterfacelayer.Suchsolutionmakesthearchitecturenotonlymoreerror-resistantbutalsomoreflexibleforchanges.ThepresentationlayerconsistsofthegraphicaluserinterfacewrittenintheJSFtechnologyandunderlyingbackingbeansobjects.ItcommunicateswiththeServicelayerthroughtheserviceinterfaces.Servicelayeristhecentralbusinesspartofthesystemwhere,onthebasisoftheuserinputdata,properdecisionsaremade.ItalsotranslatesinputdataintoexplicitformunderstoodfortheDataaccesslayer,withwhichcommunicationtakesplacebymeansofDataaccessinterfacelayer.TheDataaccesslayercooperateswithDataMapperlayerandisresponsiblefordataexchangewithdatabase.TheDataMapperlayertalksviaJDBCtodatabasetoaskrequireddata.ThisisalayerwhereiBatisDataMapperplaysthemainrole.V.JSF-SPRINGINTEGRATIONInanutshell,JSFSpringintegrationmakesSpringmanagedbeansvisibleasvariablestoJSF,justasiftheSpringbeansareconfiguredasJSFmanagedbeans.BeforedivingintotheintegrationspecificsofJavaServerFaces,thegeneralintegrationstepforanywebframeworkmustbesetforth.Allthatneedtobedone,istodeclareContextLoaderListenerinthestandardJEEservletweb.xmldeploymentdescriptor.ThislistenerinitializestheSpringsWebApplicationContextthatcontainsallofthebusinessbeansintheapplication.(Fig.4).ThesecondstepintheintegrationbetweenSpringandJSFisspecificjustforJSF.ThekeyclassusedinthisprocessisDelegatingVariableResolver.Toconfigurethisvariablethefaces-context.xmlfilemustbeedited.AfteropeningtagtagmustbeaddedandwithinitthepointingtotheSpringsDelegatingVariableResolvermustbeput.Theexamplefaces-config.xmlfileispresentedin.TheDelegatingVariableResolverdelegatesvaluelookupstothedefaultresolverofthe3underlyingJSFimplementation,andthengoingtotheSpringsbusinesscontextWebApplicationContext.ThisallowstoeasilyinjectdependenciesintoonesJSF-managedbeans.Exampleoffaces-config.xmlfilefromHotelRVI.JSFANDGETMETHOD.TheJSFonlyrecommendedmethodforsendinginputdatafromanonlineformtoanapplicationserveristhePOSTmethod,thoughsometimesthereisastrongneedforusetheGETmethodinstead.IntheHotelReservationSystemtheGETmethodisusedduringtheregistrationprocessforbringingaboutuseraccountactivation.ThecommonwaytoimplementtheGETmethodistocreateaspecialfilterwhichcanmanipulatetheheaderorcontents(orboth)ofarequestorresponse.ToputGETmethodintooperation,incaseofJavaServerFaces,thefollowingalgorithmmustbefulfilledinthebodyofthefilter:1.Getparametersfromtherequest.2.Createappropriatebackingbeanobjectaccordinglytotheviewthatwillbeusedfurther.3.Storethebackingbeanobjectinthecurrentsession.4.SetchangedJSFcontextascurrent.5.CreateviewandstoreitintheJSFcontext.6.Executebackingbeansmethods.TheHotelReservationSystemwasalsobasedontheSpringlibrary,hencesomechangestotherawalgorithmwerenecessary.TheforemostmethodforanyfilterisdoFilter()wheretheproperfiltrationhappens.publicvoiddoFilter(ServletRequestrequest,ServletResponseresponse,FilterChainchain)throwsIOException,ServletExceptionFacesContextfacesContext=getFacesContext(request,response);if(facesContext!=null)request.getRequestDispatcher(4facesContext.getViewRoot().getViewId().forward(request,response);elsechain.doFilter(request,response);ThedoFiltermethodfromGETfilterimplementationAsitmaybeseenonFig.6,anadditionalfunctionimplementingthepresentedalgorithmwasusedtokeepthesourcecodeclearandeasy-to-read.Createappropriatebackingbeanobject.AlmostallbackingbeansfromHotelReservationSystemhaveatleastonepropertyofSpringmanaged-beanorigin.Becauseofthat,itisnecessarytosetthispropertyafterbackingbeanobjectcreation.WebApplicationContextwac=WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);RegisterServiceregisterService=(RegisterService)wac.getBean(registerService);ConfirmBeanconfirmBean=newConfirmBean();confirmBean.setRegisterService(registerService);Creatingbackingbeanobjectandsettingspringoriginproperty.GettingSpringmanaged-beanobjectrequiresoperatingonSpringsWebApplicationContextobjectthatisinitialisedduringtheserverstart-up.SetchangedJSFescontextascurrent.WhenstoringbackingbeanobjectinthesessionthewholeFacescontextbecomeschanged,thereforeitmustbesetascurrentinorderallmodificationstakeplace.FacesContextFactorycontextFactory=(FacesContextFactory)FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);LifecycleFactorylifecycleFactory=(LifecycleFactory)FactoryFinder.5getFactory(FactoryFinder.LIFECYCLE_FACTORY);Lifecyclelifecycle=lifecycleFactory.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE);facesContext=contextFactory.getFacesContext(servletContext,req,res,lifecycle);ProtectedFacesContext.setFacesContextAsCurrentInstance(facesContext);SettingJSFcontextascurrentBeforetheactualsettingcontextintocurrent,itisindispensabletograbLifecycleobject.LifecyclemanagestheprocessingoftheentirelifecycleofaparticularJSFrequest.ItisresponsibleforexecutingallofthephasesthathavebeendefinedbytheJSFspecification,inthespecifiedorder,unlessotherwisedirectedbyactivitiesthatoccurredduringtheexecutionofeachphase.AninstanceofLifecycleiscreatedbycallingthegetLifecycle()methodofLifecycleFactory,foraspecifiedlifecycleidentifier.Becausethisinstanceissharedacrossmultiplesimultaneousrequests,itmustbeimplementedinathread-safemanner.UsingthecurrentLifecycleobjectalongwithServletContext,HttpServletReqestandHttpServletResponseobjectstheFacesContextcanbeupdatedandbecomesuptodate.CreateviewandstoreitintheJSFcontext.AftermakingFacescontextactual,thenewviewissupposedtobecreatedandaddedtothiscontext,neverthelessitisnotpossibletodoitwithusageofnewoperator,insteadithastobedoneinanindirectmanner.UIViewRootview=facesContext.getApplication().getViewHandler().createView(facesContext,/confirm/register.jsp);facesContext.setViewRoot(view);6CreatingnewviewandstroingitinFacescontextThecreateView()methodofViewHandlerobjectconstructsandreturnanewUIViewRootinstanceinitializedwithinformationfromtheargumentFacesContextandviewId.TheviewedparameterisalwaysStringvariablerepresenting(relativeto/WEB-INF/directory)pathwherethedefinitionfileislocated.AsshowninFig.9thedefinitionoftheviewisplacedinordinaryJSPfileandislocatedinsubdirectoryofaWEB-INFdirectory.ExecutingbackingbeansmethodsThelaststepistheactualexecutionofmethodsoftheunderlying,propertocreatedviewbackingbeanobject.ThisexampleofthefilterfortheGETmethodwasbasedupononeusedintheHotelReservationSystem,whichworksasaregistrationconfirmationtool,sointheend,themethodofresponsibilityforthehotelmanagementconfirmationwouldbeandshouldbeinvoked:confirmBean.confirmRegistration(userId);VII.CONCLUSIONSTheHotelReservationSystemisdevelopedapplicationdesignedaccordinglytothemodernprogrammingtrendswithusageoftechnologieslikeJavaServerFaces,SpringFrameworkandiBatisDataMapper.Itsmodulararchitecturemakestheapplicationmoreerror-resistantandflexibleforanychangesthereforeeasytoaddnewfunctionality.ThecommonproblemofsendinginputdatathroughtheGETmethodhasalsobeensolved.Systemiseasytoinstallanduseandthethreemodulecompositionputswork-divisionpatternintooperation.ThisresearchwassupportedbytheTechnicalUniversityofLodzGrantK-25/1/2007/Dz.St.7中文翻译基于JavaServerFaces技术的酒店预订系统本文介绍了基于网络的酒店预订系统如何利用JavaServerFaces技术和Spring框架访问系统通过Web浏览器为用户预定酒店客房。一引言酒店预订系统是一个支持特定类型功能的软件，往往通过Web浏览器作为承载手段。其主要特点为寻找并发送一个在登记过程中给定的地址的电子邮件来预订酒店相应的房间。为了支持各酒店的组件定义的过程。酒店的组成部分是：房间，促销，包装，折扣，完成的通知等有关的事实，客人来到酒店，并收到钥匙，以及房间预订系统预订的过程。二JavaServerFaces图形用户界面是每一个计算机程序的关键部分，其承载与用户的交互的责任。这应该是灵活的应用程序的一部分，这意味着容易因用户需求产生更改，但是无疑的可以增加用户友的好性。令人遗憾的是，发展中的主要过程需要好的用户界面，通常造成的是开发人员的工作和时间泛滥，并且使整个开发过程涉及JavaServerFaces（JSF）这一领域的技术。这种整体的，基于构件的，软件开发人员所面临的长期问题的解决有一个具体的目标：使网站发展速度和复杂性掩盖了很多种类的技术。JSF技术更容易隐藏的是一个服务器的端用户对基于Java技术的Web应用程序界面框架。JSF的技术的主要组成部分如下：以UI组件为代表的并且管理他们，处理事件，执行服务器交互和数据转换，定义页面导航，支持国际和普及，并为所有这些功能提供扩可展性的技术支持。两个JavaServerPages定制标记库在JSP页面表示UI组件和布线组件的服务器端的用户界面与JSF技术在服务器上运行，并返回客户端（在这种情况下浏览器）由于基于Web的应用程序。如桌面浏览器，手机和PDA（多个客户端），JSF的已经以不同的方式展示了强大的组件体系结构。至于浏览器，因为它主要用于JSF，默认的渲染技术是HTML4.0，尽管像其他的WML或SVG也有可能。JSF技术的最大优势之一是，它提供了一个干净的分离行为层和表示层和表示层的架构。三Spring框架Spring是一个轻量级，控制反转容器，它的创建解决了企业应用发展.Spring的复杂性使得可以使用普通的JavaBeans实现的东西，以前只可能与EJB的相关联。任何Java应用程序能够受益于Spring，简单来说，测试能力和松散的耦合。当作为一个整体，这些模块提供的一切需要发展的企业来进行应用，虽然不一定要有充分的构建Spring框架的应用程序。人们可以从中挑选适合的模块，只有那些最好的应用，而忽略其他方面。这一战略是为酒店预订系统选择了自构框架的核心价值主张之一，并且是社会的选择方向，没有强迫任何一个适用于特定的架构，技术或方法，Spring还提供了与第三个数字一体化的便利机制-框架（也与JSF和iBatis）。四iBATISDataMapper的APACHEiBatis的JDBC在apache-数据库和Java基于数据映射器提供了简单和灵活的运输方式之间的关系，.Net或Ruby应用程序的数据。与流行的Hibernate库，8iBatis的并没有直接配合，以表或列或字段，而是，它的存储过程或使用简单的XML描述符开始的开发，以达到对所需数据的应用。产生只有SQL语句的结果对象。iBatis的框架几乎任何数据库可以映射到任何对象模型，是非常传统的设计，甚至坏designs.Simplicity宽容，是与其他框架相比iBatis的主要优点。酒店预订系统，主要是建立基于JSF技术的同时辅助库，Spring与iBATIS的用户界面。应用程序体系结构，该系统的组成模块。每一层和适当的分隔与界面层。这种解决方案不仅能降低更多的错误发生可能性，也能产生更灵活的变化。表示层组成的图形用户在JSF支持bean对象技术编写的界面。它传达的是在那里，对用户输入数据的基础上，适当的决定是系统的核心业务的一部分，通过服务层。这也意味着为数据访问层明确了解的形式，而沟通需要通过数据访问接口是指数据访问层与数据输入数据映射层进行合作，并与数据库上进行数据交换的数据映射层负责通过JDBC数据库谈判要求所需的数据。这是一个在iBatis的数据映射层起着主要作用。五JSF的Spring集成概括地说，JSF的spring的整合使Spring管理类在JSF变量可见，就像spring为JSF管理beans到JavaServerFaces，任何Web框架综合集成一体化的具体步骤，必须配置forth.All需要做的事，是标准的J2EEservlet的ContextLoaderListener的web.xml部署文件。这个监听器初始化Spring的WebApplicationContext的，它包含所有在应用程序的业务类。在spring和JSF之间的整合只是第二个步骤是具体为JSF。课堂上使用的关键在这个过程中。要配置这个变量在faces-context.xml文件必须被编辑。开幕后标签指向Spring的DelegatingVariable分解必须付诸表决。这个例子的faces-config.xml文件。代表们的值查找到相关的JSF实现的默认解析器，然后到Spring的业务范围内的WebApplicationContext。这使得很容易注入一的JSF管理的bean依赖关系。示例的faces-config.xml文件从酒店冗余接点JSF只建议应用的一个利用表格获取输入数据到应用服务器的方法是POST方法，虽然有时也有一种强烈的