毕业设计外文文献-Spring 集成带有Spring Boot的Spring流

附录A外文翻译—原文部分Gutierrez,ProSpringBoot2,/10.1007/978-1-4842-3676-5_11SpringIntegrationandSpringCloudStreamwithSpringBootInthischapter,IshowyouoneofthebestintegrationframeworksfortheJavacommunity:theSpringIntegrationproject,whichisbasedontheSpringFramework.IalsopresenttheSpringCloudStream,whichisbasedonSpringIntegration.Itcreatesrobustandscalableevent-drivenmicroservicesconnectedtosharedmessagingsystems—alldonewithSpringBoot.Ifwetakealookatsoftwaredevelopmentandbusinessneeds,asadeveloperoranarchitect,wearealwayslookingathowtointegratecomponentsandsystems,eitherinternalorexternaltoourarchitecture,andprobewhatisfullyfunctional,highlyavailable,andeasytomaintainandenhance.Thefollowingarethemainusescasesthatdevelopersorarchitectstypicallyface.•\ Creatingasystemthatdoesareliablefiletransferorfileanalysis.Mostoftheapplicationsoutthereneedtoreadinformationfromafileandthenprocessit,soweneedtocreaterobustfilesystemsthatsaveandreaddatabutalsoshareanddealwiththesizeofthefiles.•\ Theabilitytousedatainasharedenvironmentwheremultipleclients(systemsorusers)needaccesstothesamedatabaseorthesametableanddooperationsanddealwithinconsistency,duplication,andmore.•\ Remoteaccesstodifferentsystems,fromexecutingremoteprocedures,tosendingalotofinformation.Wealwayswanttohavethisinrealtimeandinanasynchronousway.Theabilitytogetaresponseasfastaspossiblewithoutforgettingthattheremotesystemalwaysneedstobereachable;inotherwords,havethefaulttoleranceandhighavailabilityrequired.•\ Messaging—fromabasicinternalcalltobillionsofmessagespersecondtoremotebrokers.Normally,wedomessaginginanasynchronousway,soweneedtodealwithconcurrency,multithreading,speed(networklatency),highavailability,faulttolerance,andsoforth.Howcanwesolveorimplementalloftheseusecases?Almost15yearsago,softwareengineersGregorHohpeandBobbyWoolfwroteEnterpriseIntegrationPatterns:Designing,BuildingandDeployingMessagingSolutions(Addison-Wesley,2003).ThisbookexposesallthemessagingpatternsneededtosolvetheusecasesthatImentioned.Itgivesabetterunderstandingonhowsystemsinterconnectandwork,andhowyoucancreatearobustintegrationsystemwithapplicationarchitecture,object-orienteddesign,andmessage-oriented.Inthefollowingsections,I’llshowyousomeofthesepatternsusingtheSpringIntegrationprojectfromtheSpringFramework.SpringIntegrationPrimerSpringIntegrationisasimplemodelforimplementingenterpriseintegrationsolutions.Itfacilitatestheasynchronousandmessage-drivenwithinaSpringBootapplication.Itimplementsalltheenterpriseintegrationpatternsforcreatingenterprise,robust,andportableintegrationsolutions.TheSpringIntegrationprojectoffersawaytohavecomponentsthatarelooselycoupledformodularityandtestability.Ithelpstoenforcetheseparationofconcernsbetweenyourbusinessandintegrationlogic.SpringIntegrationexposesthefollowingmaincomponents.•\ Message.ThisisagenericwrapperforanyJavaobject.Itconsistsofheadersandapayload.TheheadersnormallyhaveimportantinformationlikeID,timestamp,correlationID,andreturnaddress;andofcourse,youcanaddyourown.Thepayloadcanbeanytypeofdata,fromanarrayofbytestocustomobjects.Youcanfinditsdefinitioninthespring-messagingmoduleintheorg.springframework.messagingpackage.publicinterfaceMessage<T>{TgetPayload();MessageHeadersgetHeaders();}Asyoucansee,there’snothingfancyinthedefinition.•\ Messagechannel.Pipesandfiltersarchitecture,verysimilartothecommandyouuseinaUNIXsystem.Touseit,youneedtohaveproducersandconsumers;theproducersendsthemessagetothemessagechannelandaconsumerreceivesit(seeFigure11-1).Figure11-1. MessagechannelThismessagechannelfollowsmessagingpatterns,suchasthePoint-to-PointandPublish/Subscribemodels.SpringIntegrationoffersseveralmessagechannels,likepollablechannels(thatallowsyoutohavebufferingmessageswithinaqueue)orsubscribablechannelsfortheconsumers.•\ Messageendpoint.Afilterthatconnectstheapplicationcodetothemessagingframework.MostoftheseendpointsarepartoftheEnterpriseIntegrationPatternsimplementations.•\ Filter.Amessagefilterdetermineswhenamessageshouldbepassedtotheoutputchannel.•\ Transformer.Amessagetransformermodifiesthecontentorstructureofamessageandpassesittotheoutputchannel.•\ Router.Amessagerouterdecideswhattodoandwheretosendthemessagebasedonrules.Theserulescanbeintheheadersorinthesamepayload.Thismessagerouterhasmanypatternsthatcanbeapplied.I’llshowyouatleastoneofthem.•\ Splitter.Amessagesplitteracceptsamessage(inputchannel),anditsplitsandreturnsnewmultiplemessages(outputchannel).•\ Serviceactivator.Thisisanendpointthatactsasaservicebyreceivingamessage(inputchannel)andprocessesit.Itcaneitherendtheflowoftheintegrationoritcanreturnthesamemessageoranentirelynewone(outputchannel).•\ Aggregator.Thismessageendpointreceivedmultiplemessages(inputchannel);itcombinestheminanewsinglemessage(baseonareleasestrategy)andsendsitout(outputchannel).•\ Channeladapters.Thisisaparticularendpointthatconnectsamessagechanneltoothersystemsortransports.SpringIntegrationoffersinboundoroutboundadapters.Wherearesponseisrequired,itoffersagatewayadapter.Youseethatthesearethemostcommonlyused.Why?IfyoursolutionislookingtoconnecttoRabbitMQ,JMS,FTP,aFileSystem,HTTPoranyothertechnology,SpringIntegrationhastheadaptertoconnecttoitwithoutyoucodinganyclient.ItwouldtakeawholenewbooktowriteaboutSpringIntegrationandmessagepatterns,messagingchannels,adapters,andmore,butifyouareinterestinginthistechnology,IrecommendProSpringIntegrationbyDr.MarkLui(Apress,2011).Inthenextsection,I’llshowyousomeofthecomponentsandpatterns,whichareenoughtogetyoustarted.ProgrammingSpringIntegrationWithSpringIntegration,thereareseveralwaystoconfigureallthecomponents(message,messagechannelandmessageendpoints):XML,JavaConfigclasses,annotations,andthenewIntegrationDSL.ToDoAppwithSpringIntegrationLet’sstartwiththewell-knownToDoAppanduseSpringIntegrationrightaway.Youcanstartfromscratchoryoucanfollowalonginthenextsectionstolearnwhatyouneedtodo.Ifyouarestartingfromscratch,thenyoucangotoSpringInitializr(https://start.spring.io)andaddthefollowingvaluestothefields.•\ Group:com.apress.todo•\ Artifact:todo-integration•\ Name:todo-integration•\ PackageName:com.apress.todo•\ Dependencies:SpringIntegration,LombokYoucanselecteitherMavenorGradleastheprojecttype.ThenyoucanpresstheGenerateProjectbutton,whichdownloadsaZIPfile.UncompressitandimporttheprojectinyourfavoriteIDE(seeFigure11-2).Figure11-2. SpringInitializrAsyoucanseefromthedependencies,wearenowusingSpringIntegration.YoucanreuseorcopytheToDoclass(seeListing11-1).Listing11-1. com.apress.todo.domain.ToDo.javapackagecom.apress.todo.domain;importlombok.Data;importjava.time.LocalDateTime;importjava.util.UUID;@DatapublicclassToDo{privateStringid;privateStringdescription;privateLocalDateTimecreated;privateLocalDateTimemodified;privatebooleancompleted;publicToDo(){this.id=UUID.randomUUID().toString();this.created=LocalDateTime.now();this.modified=LocalDateTime.now();}publicToDo(Stringdescription){this();this.description=description;}publicToDo(Stringdescription,booleancompleted){this(description);pleted=completed;}}Listing11-1showsyouwell-knownToDoclass.There’snothingnewaboutit.Next,let’screateaToDoIntegrationclassthathasthefirstSpringIntegrationflowusingDSL(seeListing11-2).Listing11-2. egration.ToDoIntegration.javapackageegration;importcom.apress.todo.domain.ToDo;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importegration.channel.DirectChannel;importegration.config.EnableIntegration;importegration.dsl.IntegrationFlow;importegration.dsl.IntegrationFlows;importegration.dsl.channel.MessageChannels;@EnableIntegration@ConfigurationpublicclassToDoIntegration{@BeanpublicDirectChannelinput(){returnMessageChannels.direct().get();}@BeanpublicIntegrationFlowsimpleFlow(){returnIntegrationFlows.from(input()).filter(ToDo.class,ToDo::isCompleted).transform(ToDo.class,toDo->toDo.getDescription().toUpperCase()).handle(System.out::println).get();}}Listing11-2showsabasicexample.Thisexamplereceivesamessagefromtheinputchannel(aToDoinstance),filtersthismessageifonlytheToDoiscompleted,andthentransformsthemessagebyuppercasingthedescriptionandhandlesitbyprintingitontheconsole.Allofthisiscalledanintegrationflow.Butlet’stakeadeeperlookinside.•\ IntegrationFlow.ExposestheDSLasabean(itisrequiredtohavea@Beanannotation).ThisclassisafactoryfortheIntegrationFlowBuilderanddefinestheflowoftheintegration.Itregistersallthecomponents,suchasmessagechannels,endpoints,andsoforth.•\ IntegrationFlows.ThisclassexposesafluentAPIthathelpsbuildingtheintegrationflow.It’seasytoincorporateendpointssuchastransform,filter,handle,split,aggregate,route,bridge.Withtheseendpoints,youcanuseanyJava8(andabove)lambdaexpressionsasanargument.•\ from.Thisisanoverloadedmethodwhereyounormallypassthemessagesource;inthiscase,wearecallingtheinputmethodthatreturnsaDirectChannelinstancethroughtheMessageChannelsfluentAPI.•\ filter.ThisoverloadedmethodpopulatesMessageFilter.TheMessageFilterdelegatestoaMessageSelectorthatsendsthemessagetothefilter’soutputchanneliftheselectoracceptsthemessage.•\ transform.Thismethodcanreceivealambdaexpression,butactuallyreceivesGenericTransformer<S,T>,whereSisthesourceandtheTisthetypethatitisconvertedto.Herewecanuseout-of-the-boxtransformers,likeObjectToJsonTransformer,FileToStringTransformer,andsoforth.Inthisexample,wearetheclasstype(ToDo)andalambdaisexecuted;inthiscase,gettingtheToDo’sdescriptionandtransformingittouppercase.•\ handle.ThisisanoverloadedmethodthatpopulatesServiceActivatingHandler.Normally,wecanuseaPOJOthatallowsyoutoreceivethemessageandeitherreturnanewmessageortriggeranothercall.Thisisausefulendpointthatwearegoingtoseeinthischapterandinthenextoneasaserviceactivatorendpoint.•\ @EnableIntegration.HereweareusinganewannotationthatsetsupalltheSpringIntegrationbeansthatweneedforourflow.Thisannotationregistersdifferentbeans,likeerrorChannel,LoggingHandler,taskScheduler,andmore.Thesebeanscomplementourflowinanintegrationsolution.ThisannotationisnecessarywhenusingJavaconfigurations,annotations,andDSLinaSpringBootapplication.Don’tworrytoomuchifthislooksdifferentfromwhatyouhaveprobablydoneinthepastwithintegrationsolutions.YouwillgetmorecomfortablewithalltheexamplesthatIshowyounext,anditgetseveneasier.Next,let’screatetheToDoConfigclassinwhichaToDoissentthroughtheinputchannel(seeListing11-3).Listing11-3. com.apress.todo.config.ToDoConfig.javapackagecom.apress.todo.config;importcom.apress.todo.domain.ToDo;importorg.springframework.boot.ApplicationRunner;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importorg.springframework.messaging.MessageChannel;importorg.springframework.messaging.support.MessageBuilder;@ConfigurationpublicclassToDoConfig{@BeanpublicApplicationRunnerrunner(MessageChannelinput){returnargs->{input.send(MessageBuilder.withPayload(newToDo("buymilktoday",true)).build());};}}Listing11-3showstheApplicationRunnerbean,whereitisexecutedwhentheapplicationstarts(seethattheMessageChannelisinjected—theonedeclaredintheToDoIntegrationclass).ThismethodisusingaMessageBuilderclassthatoffersafluentAPIthatcreatesmessages.Inthiscase,theclassisusingthewithPayloadmethodthatcreatesanewToDoinstance,markedascompleted.Nowit’stimetorunourapplication.Ifyourunit,youshouldseesomethingsimilartothefollowingoutput....INFO39319-[main]o.s.i.e.EventDrivenConsumer:startedsimpleF.egration.config.ConsumerEndpointFactoryBean#2INFO39319-[main]c.a.todo.TodoIntegrationApplication:StartedTodoIntegrationApplicationin0.998seconds(JVMrunningfor1.422)GenericMessage[payload=BUYMILKTODAY,headers={id=c245b7a3-3191-641b-­7ad8-1f6eb950f62e,timestamp=1535772540543}]...Rememberthatamessageisaboutheadersandpayload,whichiswhywegettheGenericMessageclasswithapayloadwherethefinalmessageis“BUYMILKTODAY”andheadersthatincludetheIDandthetimestamp.Thisistheresultofapplyingafilterandtransformingthemessage.

附录B外文翻译—译文部分Spring集成带有SpringBoot的Spring流在本章中，我向大家展示了java社区最好的集成框架之一：基于Spring框架的Spring集成项目。我还介绍了基于Spring集成的Spring流。它创建了连接到共享消息系统的强大和可扩展的事件驱动的微服务——所有这些都是用SpringBoot完成的。如果我们看看软件开发和业务需求，作为一个开发者或建筑师，我们总是在考虑如何集成组件和系统，无论是内部的还是外部的，我们的架构，并探索什么是完全功能的，高度可用的，易于维护和增强。以下是开发者或架构师通常会面对的主要用例。•创建一个能够进行可靠的文件传输或文件分析的系统。大部分的应用程序都需要从文件，然后处理它，所以我们需要创建健壮的文件系统保存和读取数据，并共享和处理文件的大小。*在多个共享环境中使用数据的能力客户（系统或用户）需要访问同一数据库或做同样的操作和处理不一致的问题，重复，还有更多。*从执行远程访问到不同系统程序，发送大量信息。我们一直想拥有这在实时和异步的方式。能够在不忘记远程系统总是需要可到达的情况下尽快得到响应；换句话说，具有所需的容错性和高可用性。•短信——从基本的内部通话到每秒数十亿条短信，再到远程经纪人。通常，我们用异步方式进行消息传递，因此我们需要处理并发、多线程、速度（网络延迟）、高可用性、容错性等问题。我们如何解决或实现所有这些用例？大约15年前，软件工程师GregorHohpe和BobbyWoolf撰写了《企业集成模式：设计、构建和部署消息传递解决方案》（addison-wesley，2003年）。这本书公开了解决我提到的用例所需的所有消息模式。它可以更好地理解系统如何相互连接和工作，以及如何创建一个具有应用程序体系结构、面向对象设计和面向消息的健壮集成系统。在下面的章节中，我将使用Spring框架中的Spring集成项目向您展示其中的一些模式。Spring集成底漆Spring集成是实现企业集成解决方案的一个简单模型。它方便了Spring启动应用程序中的异步和消息驱动。它实现了创建企业、健壮和可移植的集成解决方案的所有企业集成模式。该Spring集成项目提供了一种方法，使组件松散耦合模块化和可测试性。它有助于在业务和集成逻辑之间强制分离关注点。Spring集成公开了以下主要组件。•信息。这是任何java对象的通用包装器。它由头和有效载荷组成。标头通常有重要的信息，如id、时间戳、相关id和返回地址；当然，您可以添加自己的信息。有效负载可以是任何类型的数据，从字节数组到自定义对象。您可以在.org中的春季消息模块中找到它的定义。Spring框架。消息包。publicinterfaceMessage<T>{TgetPayload();MessageHeadersgetHeaders();}正如你所看到的，没有什么花哨的定义。•留言频道。管道和过滤器架构，非常类似于在unix系统中使用的命令。要使用它，你需要有生产者和消费者；生产者将消息发送到消息通道，消费者接收它（见下图）。此消息通道遵循消息传递模式，如点对点和发布/订阅模型。Spring集成为消费者提供了一些消息通道，如可传播的通道（允许您在队列中拥有缓冲消息）或可订阅的通道。•信息终点。将应用程序代码连接到消息传递框架的筛选器。这些端点大多是企业集成模式的实现。•\过滤。消息筛选器决定何时将消息传递到输出通道。•变压器。消息转换器修改消息的内容或结构并将其传递到输出通道。•路由器。消息路由器根据规则决定做什么和向何处发送消息。这些规则可以在标头中，也可以在同一个有效载荷中。这个消息路由器有很多模式可以应用。我至少会给你看其中一个。拆分器。消息拆分器接受消息（输入通道），然后拆分并返回新的多个消息（输出通道）。•服务激活器。这是一个端点，通过接收消息（输入通道）并处理它来充当服务。它既可以结束集成的流，也可以返回相同的消息或一个全新的消息（输出通道）。·\聚合器。此消息端点接收到多个消息（输入通道）；它将它们合并到一个新的单一消息（基于发布策略）中并发送出去（输出通道）。•\通道适配器。这是一个特定的端点，将消息通道连接到其他系统或传输。Spring集成提供入站或出站适配器。在需要响应的情况下，它提供网关适配器。你看，这些是最常用的。为什么？如果您的解决方案是要连接到rabbitmq、jms、ftp、一个文件系统、http或任何其他技术，那么Spring集成就可以在不对任何客户端进行编码的情况下连接到它。如果你对这项技术感兴趣，我建议MarkLui博士（apress，2011年）写一本关于Spring集成和消息模式、消息通道、适配器等等的新书。在下一节中，我将向您展示一些组件和模式，这些组件和模式足以让您开始。编程Spring集成有了Spring集成，有几种方法来配置所有的组件（消息、消息通道和消息端点）：xml、javaconfig类、注释和新的集成dsl。带有Spring集成的todo应用程序让我们从著名的todo应用程序开始，立即使用Spring集成。你可以从头开始，也可以在接下来的章节里学习你需要做的事情。如果你是从零开始，那么你可以去Spring初始化（https://start）。spring.io），并在字段中添加以下值。•小组讨论•艺术品：整合•名字：整合•包装名称：来吧•依赖：Spring整合，龙目您可以选择maven或gladle作为项目类型。然后您可以按下生成的项目按钮，该按钮可以下载zip文件。解压缩并导入您最爱的代码中的项目（见下图）。从依赖关系中可以看出，我们现在使用的是Spring积分。您可以重用或复制托多类（见清单11-1）。清单11-1.com.apress.todo.domain.ToDo.javapackagecom.apress.todo.domain;importlombok.Data;importjava.time.LocalDateTime;importjava.util.UUID;@DatapublicclassToDo{privateStringid;privateStringdescription;privateLocalDateTimecreated;privateLocalDateTimemodified;privatebooleancompleted;publicToDo(){this.id=UUID.randomUUID().toString();this.created=LocalDateTime.now();this.modified=LocalDateTime.now();}publicToDo(Stringdescription){this();this.description=description;}publicToDo(Stringdescription,booleancompleted){this(description);pleted=completed;}}清单11-1显示你的知名ToDoclass。这没什么新鲜的。接下来，让我们创建一个有第一个使用dsl的Spring集成流的Todo集成类（参见清单11-2）。清单11-2.egration.ToDoIntegration.javapackageegration;importcom.apress.todo.domain.ToDo;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importegration.channel.DirectChannel;importegration.config.EnableIntegration;importegration.dsl.IntegrationFlow;importegration.dsl.IntegrationFlows;importegration.dsl.channel.MessageChannels;@EnableIntegration@ConfigurationpublicclassToDoIntegration{@BeanpublicDirectChannelinput(){returnMessageChannels.direct().get();}@BeanpublicIntegrationFlowsimpleFlow(){returnIntegrationFlows.from(input()).filter(ToDo.class,ToDo::isCompleted).transform(ToDo.class,toDo->toDo.getDescription().toUpperCase()).handle(System.out::println).get();}}清单11-2是一个基本例子。此示例接收来自输入通道（一个todo实例）的消息，如果仅完成该todo，则筛选此消息，然后通过提升描述来转换该消息，并通过在控制台上打印来处理该消息。所有这些都被称为集