基于Web services和BPEL实现企业应用集成

本文介绍了传统企业应用集成的架构,阐述了其存在的弊端,在认真分析Webservice和BPEL两大关键技术的基础上,提出了一种基于Webservices和BPEL技术实现企业应用集成的新架构,并给出新架构中关键部分的解决方案。     

Integration of transient Web services into a virtual peer to peer Web service registry

Transient Web service provisioning implies a variety of different requirements that are hard to meet in traditional Web service environments. Currently, Web service brokerage focuses on centralized or replicated architectures. We argue that such systems are not efficient when it comes to dynamic, respectively ad hoc, Web service provisioning. We propose a distributed peer to peer Web service registry solution based on lightweight Web service profiles. We further introduce the notion of views that allow the specification of arbitrary contexts of Web services and provide a working example to illustrate our approach. Finally, we present a prototype that uses tuple spaces as global storage and communication means.     

语义Web服务——Web服务的扩展

语义Web服务是应用语义Web技术对Web服务的扩展.使信息具有语义就是用计算机内的Ontology中的概念作标记符对信息进行标记,对该过程予以支持的就是语义Web技术,即Ontology的构建技术、Ontology的使用技术(语义推理技术)和信息的语义标记技术.语义Web技术对Web服务的扩展可具体化为两项任务:服务提供者、服务请求者和服务注册处三类服务主体均内置Ontology;发布、查找和绑定三种交互信息均采用语义标记.     

Putting labs online with Web services

This paper describes an online experiment system that is based on Web services designed to support interoperable, machine-to-machine interaction over a network, and can also integrate heterogeneous resources. A service-oriented architecture was devised for online experiment systems, enabled by Web service protocols, and a methodology for wrapping the operations of the instruments into Web services. Although these methods aren't suitable for time-critical missions or applications that need real-time control, they do work for controlling standard commercial instruments over low-speed or unreliable communication networks. Using this framework, an online experiment system for students can be created that incorporates a great variety of instruments and that users can access without installing special software.     

Web services push

Industry heavyweights Hewlett-Packard, IBM, Microsoft, Oracle, Sun Microsystems, BEA Systems and webMethods, have signed on to support VeriSign’s open standard-based framework that will let these vendors and others add security and authentication services to their Web services development tools.     

Web services notifications

As Web services have matured, they've also acquired the need for asynchronous push capabilities. Early Web services, such as those for getting traffic or weather reports or for performing currency exchange-rate calculations, were seemingly all remote procedure calls-oriented. In an RPC system, the receiver typically performs the requested service and sends a response back to the caller over the same connection on which the request arrived, which means the details required by the service for sending a reply are implicit in the RPC network connection. Unfortunately, these kinds of implied communication details are wholly inadequate for asynchronous push Web services.     

Web services policies

In addition to the basic Web services architecture, various specifications already exist for adding security, reliable messaging, and transaction mechanisms to Web services messages. All of these include numerous options to let them meet various application requirements. Specifying option choices for Web services in basic communication areas such as security, reliable messaging, privacy, and transactions is the immediate goal underlying efforts to define Web services policies.     

Semantic Web services

The authors propose the markup of Web services in the DAML family of Semantic Web markup languages. This markup enables a wide variety of agent technologies for automated Web service discovery, execution, composition and interoperation. The authors present one such technology for automated Web service composition.     

Understanding Web services

Web services are a new breed of Web applications. These independent application components are published on to the Web in such a way that other Web applications can find and use them. They take the Web to its next stage of evolution, in which software components can discover other software components and conduct business transactions. Examples of Web services include a credit card service that processes credit card transactions for a given account number, a market data service that provides stock market data associated with a specified stock symbol, and an airline service that provides flight schedule, availability, and reservation functionalities. Major vendors like IBM, Microsoft, Hewlett-Packard, and Sun, among others, are investing heavily in Web services technology. Ranging from simple to complex, Web services bring the promise of flexible, open-standards-based, distributed computing to the Internet     

Scaling Web services with capacity provision networks

With the increasing proliferation of c-commerce and e-business activities, many service providers are turning to Web caching solutions to move important content and processes closer to end users. Uncertainties in user demand and rapid market changes pose significant impediments to effective cache planning and deployment solutions, however. The authors have developed capacity provision networks to support a specific type of Web caching in the vertical segment of ISPs, NSPs, and similar entities. In this scenario, an entity can be a provider at one time and a user at another, depending on cache capacity requirements.     

Web知识本体集成

WWW(World Wide Web)是一个开放、分布式的环境,其中包含了大量的信息,使用知识本体可以帮助用户进行网络信息获取。在WWW上存在许多版本的知识本体,知识本体之问可以通过引用关系来实现知识本体之问的互操作和重用。由于WWW的快速增长特性以及Web知识本体之问的相对独立性,如何集成知识本体成为更好地支持Web知识本体重用的关键问题。本文提出了一种将知识本体表示转换为一阶谓词逻辑形式表示的方法,并在此基础上提出了检查知识本体与其引用的知识本体一致性的方法以及实现知识本体集成方法。     

Web Services集成技术

本文首先介绍了Web Services的基本概念和应用背景,在此基础上分析当前使用的Web Services合成的意义。然后阐述基本的Web Services合成方式及其介绍在Web服务中消除语义的方法,重点研究了动态服务合成过程和语义分析方法,最后对于Web Services的集成应用进行了展望。     

Putting the "Web" into Web services. Web services interaction models.2

For pt.1 see ibid., vol.6, no.3, p. 89-91 (2002). As I discussed in my previous column, each different style of middleware promotes one or more interaction models that determine how applications based on that middleware communicate and work with each other. It is difficult to say what the best interaction models would be for Web services, mainly because the World Wide Web Consortium (W3C) is still developing the architecture. The author considers the use of remote procedure calls, Web services and messaging and interface complexity.     

基于三层组织模型的一种Web服务组合策略

在研究Web服务三层组织模型和有限状态自动机的基础上,提出了一种新的Web服务组合策略,给出了一个服务的可组合性定理,并证明了定理的正确性。该策略以Web服务三层组织模型为基础,简化了BPEL中基于有限状态自动机的Web服务自动组合,精简了服务组合流程。最后对这种新的组合策略的优缺点作了分析。     

Web services interoperability specifications

A proposed conceptual framework for analyzing Web services interoperability issues provides a context for studying existing standards and specifications and for identifying new opportunities to provide automated support, for this technology. Web services are becoming the technology of choice for realizing service-oriented architectures (SOAs). Web services simplify interoperability and, therefore, application integration. They provide a means for wrapping existing applications so developers can access them through standard languages and protocols.     

Web services choreography validation

In this paper, we propose an approach to simulation and validation of Web services choreography described by WS-CDL. Simulation of Web services choreography is important to analyze and test the choreography model written by SOA designers. On the other hand, WS-CDL specification regulates the correct behaviors a WS-CDL document has to obey. Thus, constraints are specified in WS-CDL specification including static, dynamic and implementation ones. We developed a relational calculus to capture those constraints precisely, and a corresponding algorithm for relational analysis is performed with the WS-CDL parser and simulator. Last but not least, a tool called CDLchecker is developed to facilitate designers to simulate and validate WS-CDL documents.