基于Web服务的会话模型及其比较和应用研究

Web服务的基础规范仅支持具有简单交互协议的服务调用,不能支持需要交换一系列消息交换的复杂的电子商务交互.文中首先提出了基于Web服务的会话和会话模型的概念,试图用它们来解决双方或多方之间复杂的多步骤的长运行期的交互问题,然后从新兴的描述Web服务的会话性的各种标准归纳出两种会话模型,并对它们进行了详细的分析、应用和比较,最后给出基于会话的企业间应用集成模型,综合应用了基于这两种会话模型的标准.     

基于RPC和基于REST的Web服务交互模型比较分析

传统Web服务采用基于RPC的交互模型，这种模型很难达到Web级的规模可伸缩性，因此制约了Web服务的普遍应用和进一步发展。在对传统Web服务交互模型的特点与不足进行分析、以及传统交互模型与基于REST交互模型进行比较的基础上，该文探讨了Web服务交互模型的发展方向。     

基于BPMN的Web服务并发交互机制

如何抽象描述复杂业务流程的交互是服务计算研究的重要问题。大量的国内外研究虽然关注业务流程建模,但却忽略了建模过程中组件之间的并发交互描述和实现。针对Web服务并发交互,提出一种基于BPMN的Web服务并发交互的形式化模型。首先,采用BPMN描述业务流程中的并发交互模式;其次,将BPMN并发交互模式映射到Orc语言;最后,Web服务实例表明,所提方法可有效支持Web服务并发交互抽象建模。     

基于工作流模式的OWL-S过程模型分析及其应用

确定OWL-S过程模型描述Web服务之间交互协议的能力和缺陷，为组合Web服务执行提供有效支持。将组合web服务视为基于Web服务的工作流，利用OWL-S过程模型的控制结构给出工作流模式的实现方案，分析出OWL-S描述web服务之间交互协议的能力及缺陷；在此基础上，设计并实现基于OWL-S的组合web服务执行工具，通过验证Web服务调用的有效性及Web服务之间交互协议的有效性，提高组合Web服务执行的健壮性。     

基于.NET的Web Services安全技术实现

为解决在Web应用中应用程序调用Web服务的安全性,采用一种基于.NET身份验证和授权的Web服务安全技术策略,通过将会话标识进行传递,实现Web服务的安全调用,实现了Web服务安全性的一般要求。该策略不仅易于编程而且增强了Web服务的安全性,保护了业务应用程序之间交换消息的完整性和机密性。     

基于J2EE与Web服务的第三方物流动态整合设计与实现*

Web服务为第三方物流的动态电子商务业务流程提供了一致的信息交换与集成框架,从而支持着企业交易伙伴之间更为复杂的Web交互与商务协作.为了阐述基于J2EE的Web服务动态集成化第三方物流解决方案,首先在阐述了Web服务集成概念与理论的基础上,以物流订单处理的过程为例,研究了基于Web 服务的第三方物流业务集成方法.     

基于有限状态机的Web服务测试用例生成方法

提出了一种基于有限状态模型（FSM）的测试用例生成方法。首先,FSM中的状态由Web服务与用户交互产生的中间状态表示,FSM中的状态迁移及其标注由Web服务与用户间的消息交换表示;其次,借助正则表达式来描述Web服务交互过程的所有消息交换序列,并与Web服务的WSDL文档结合产生测试数据;最后,给出了满足FSM迁移覆盖准则的测试用例生成算法,并通过实验验证了该方法的有效性。     

一个基于服务请求语言的统一Web服务框架

提出一种基于服务请求语言的统一Web服务框架UWSF。该框架通过统一的服务发布构件对外提供Web服务,并以服务项为单位进行组织,客户端通过对服务项的灵活组合获得各种定制的服务。引入服务请求语言作为客户端服务请求以及交互策略的描述手段。服务请求在服务端解释执行,使得双方的交互过程能够在会话环境中进行,并且减少了由于中间结果传榆造成的带宽占用。服务端执行基于状态图的流程级交互控制以及基于权限检查接口的服务项级权限控制,保证了会话过程的合法性与完整性。     

基于XML与Web服务的多源气田信息整合

气田信息整合的主要目标是实现自治、分布、异构数据源的自动数据交换，并为用户提供统一的全局数据视图。Web服务作为一种面向服务的分布式计算技术，提供了一种建立基于Web的复杂松耦合分布式系统框架。讨论了Web服务应用于信息整合的基本模式，提出了基于Web服务的气田信息整合体系结构和基于元数据的气田信息整合方法。系统采用XML作为数据表示和交换的标准，具有较强的灵活性和可维护性。     

基于符号模型检测的Web服务组合形式化验证

随着经济的发展和市场竞争的加剧,企业必须能够快速且准确地满足市场和用户的各种需求。Web服务组合正是由于单个Web服务不能满足企业及用户的需求而产生的一种技术,而如何确保组合的正确性来实现服务增值是一个尚未完全解决的问题。针对此问题,提出了一种基于符号模型检测器NuSMV对Web服务组合进行验证的方法,并提出了基于消息会话的Web服务有限状态自动机的形式化定义。最后实例验证了Web服务组合交互的正确性和有无死锁状态现象,进一步证明了方法的可行性。     

Web service conversation modeling: a cornerstone for e-business automation

Web services are emerging as a promising technology for effectively automating interorganizational interactions. However, despite the growing interest, several issues remain to be addressed to provide Web services with benefits similar to what traditional middleware brings to intraorganizational application integration. We identify a framework that builds on current standards to help developers define extended service models and richer Web service abstractions. The framework's main feature is a conversation metamodel derived from our analysis of e-commerce portal sites.     

A Conversational Approach to the Interaction With Web Services

The emerging standards for the specification of Web Services support the publication of the static interfaces of the operations they may execute. However, little attention is paid to the management of long-lasting interactions between the service providers and their consumers. Although this is not an issue in the case of "one-shot" services, it challenges the provision of services requiring the exchange of multiple messages between the business partners. In this article, we present a conversational model supporting the management of long-lasting interactions where several messages have to be exchanged before the service is completed. Our model aims at facilitating the consumers during the service invocation because in this way the establishment of short-term business relations can be simplified. To this extent, we provide a computational framework that can be exploited to manage a conversation between the consumer and the service provider. Our framework is inspired from the research developed in Computational Linguistics and in the area of Multi-Agent Systems to manage human-to-computer and agent-to-agent dialog. However, we employ techniques suitable to comply with the emerging Web Service standards and with the scalability requirements of the Internet.     

B2B电子商务中Web服务安全和服务质量分析

B2B电子商务可以从Web服务带来的互操作性中获得显著的效益,但同时也需要确保Web服务内在的服务质量和安全.针对B2B中Web服务的安全问题,提出了基于通用标准的解决方案;为了更好地管理Web服务的服务质量和满足客户需求,本文还设计了服务质量管理的总体架构.     

Neural personalized response generation as domain adaptation

World Wide Web - One of the most crucial problem on training personalized response generation models for conversational robots is the lack of large scale personal conversation data. To address the...     

基于Web服务的供应链信息沟通与共享

有效降低供应链成本的关键是充分实现供应链上各实体闯的信息沟通与共享，传统的实现方法是采用EDI技术，但EDI系统开发复杂、成本较高，多数中小企业难以承担。近来兴起的Web服务技术由于采用了开放的互联网标准和XML，极大地简化了跨组织系统的开发，降低了开发成本，有望成为实现供应链信息共享的重要解决方案。该文阐述了Web服务的技术要点，并给出了一个利用Web服务实现供应链信息共享的实现案例。     

Synchronizability of conversations among Web services

We present a framework for analyzing interactions among Web services that communicate with asynchronous messages. We model the interactions among the peers participating in a composite Web service as conversations, the global sequences of messages exchanged among the peers. This naturally leads to the following model checking problem: Given an LTL property and a composite Web service, do the conversations generated by the composite Web service satisfy the property? We show that asynchronous messaging leads to state space explosion for bounded message queues and undecidability of the model checking problem for unbounded message queues. We propose a technique called synchronizability analysis to tackle this problem. If a composite Web service is synchronizable, its conversation set remains the same when asynchronous communication is replaced with synchronous communication. We give a set of sufficient conditions that guarantee synchronizability and that can be checked statically. Based on our synchronizability results, we show that a large class of composite Web services with unbounded message queues can be verified completely using a finite state model checker such as SPIN. We also show that synchronizability analysis can be used to check the reliability of top-down conversation specifications and we contrast the conversation model with the Message Sequence Charts. We integrated synchronizability analysis to a tool we developed for analyzing composite Web services.     

航空订票业务的Web服务建模及组合兼容性验证

Web服务通过组合基本服务为解决复杂问题提供了方法,于是近年来越来越受到关注。当前交互式下的Web服务在实际组合中还存在诸多问题,其中就包括Web服务组合验证问题。运用Pi演算对航空订票业务的Web服务进行形式化建模,改进基于Pi演算的推理,提供一种验证多个Web服务组合是否兼容的方法。为证实该验证方法,进一步采用MWB工具展示了Web服务组合兼容性的验证过程。     

Visual modeling of RESTful conversations with RESTalk

The cost savings introduced by Web services through code reuse and integration opportunities have motivated many businesses to develop Web APIs, with ever increasing numbers opting for the REST architectural style. RESTful Web APIs are decomposed in multiple resources, which the client can manipulate through HTTP interactions with well-defined semantics. Getting the resource in the desired state might require multiple client–server interactions, what we define as a RESTful conversation. RESTful conversations are dynamically guided by hypermedia controls, such as links. Thus, when deciding whether and how to use a given RESTful service, the client might not be aware of all the interactions which are necessary to achieve its goal. This is because existing documentation of RESTful APIs describes the static structure of the interface, exposing low-level HTTP details, while little attention has been paid to conceptual, high-level, modeling of the dynamics of RESTful conversations. Low-level HTTP details can be abstracted from during the design phase of the API, or when deciding which API to use. We argue that, in these situations, visual models of the required client–server interactions might increase developers’ efficiency and facilitate their understanding. Thus, to capture all possible interaction sequences in a given RESTful conversation, we propose RESTalk, an extension to the BPMN Choreography diagrams to render them more concise and yet sufficiently expressive in the specific REST domain. We also report on the results obtained from an exploratory survey we have conducted to assess the maturity of the field for a domain-specific language and to obtain feedback for future improvements of RESTalk.     

Web Services: An Analysis of the Technology, its Benefits, and Implementation Difficulties

Software reuse and systems interoperability have been primary goals of many IT organizations, especially those that rely heavily on computer networks. Object-oriented (OO) technology has been utilized to accomplish these goals with relative success over the years; but there are many hurdles that OO technology could not overcome. One of them is due to lack of standards. An object developed in one vendor's technology cannot easily communicate with another's. Another difficulty is that the majority of software applications reside behind firewalls - security barriers that restrict communication between networks. Web services, self-describing services that can easily be consumed over the Web, is the latest trend in the industry to address the problems identified above. Web services enable a group of related applications to be programmatically invoked over the Internet. They are rapidly emerging as important building blocks for business integration. Companies are finding important Web service applications in B2B, B2C, and enterprise application integration solutions. This article reviews the technical underpinnings of Web services and discusses their business opportunities and potential benefits. It also assesses the challenges and implementation difficulties of the technology.     

Web service adaptation: A decade’s overview

With the exponential growth of communication and information technologies, adaptation has gained a significant attention as it becomes a key feature of service-based systems, allowing them to operate and evolve in highly dynamic and uncertain environments. Although several Web service standards and frameworks have been proposed and extended, existing solutions do not provide a suitable architecture, in which all aspects of monitoring and adaptation (e.g., proactive, cross-layer, and autonomic adaptation) can be expressed. In addition, the emergence of new computing environments to host and execute various types of services (Web/cloud services, big data-intensive services, mobile services, microservices, etc.) raises the need for more efficient monitoring and adaptation systems. This survey aims to bring a synthesis and a road-map to the adaptation of service-based systems. We also discuss adaptation solutions in emerging service models, such as cloud services and big services. Based on an adaptation taxonomy which we extracted from the surveyed approaches, and by identifying the main requirements and goals of service adaptation in Web, cloud and big data environments, detailed analysis and discussions, as well as the open issues, are provided.