基于PHP5和Axis实现四则运算的Web服务系统

在当今Web领域,Web Services是一个实现SOA架构的新标准,以惊人的速度发展。Axis作为一个SOAP引擎,提供创建服务器端、客户端操作的基本框架。PHP5支持对SOAP的扩展,提供和调用Web Services功能。该文给出了用PHP5来调用在Axis上发布的四则运算Web Services的实例,并给出了客户端和服务器端的SOAP传递消息过程。     

面向 Web 服务的拜占庭容错中间件的设计*

根据Web服务的特点,设计了一个拜占庭容错中间件。基于使用最广泛的SOAP引擎Axis2,屏蔽了拜占庭错误容忍算法的细节和数据传输的细节,应用程序逻辑只需要调用中间件提供的接口发送和接收消息即可。将该中间件作为SOAP引擎的传输层,使得SOAP引擎能够使用各种底层传输协议,而不是局限于某一种传输协议。基于Axis2的Web服务可以方便地使用该中间件,具备拜占庭容错能力。进行了实验分析,结果显示了设计的有效性。     

Axis上SOAP数字签名的实现

现有的SOAP引擎都没有提供对SOAP数字签名的支持，介绍了一种利用第三方API在Axis上实现SOAP数字签名的方法。这种方法可以提高系统的安全性。     

基于Axis开发Web服务的研究

Web Services已成为网络应用发展的主流,SOAP协议是Web Services的核心协议。Axis本身是基于Java语言开发的项目,它给出了一个很好的SOAP实现平台,基于它开发Web Services应用省掉了许多底层技术细节,从而使Web服务的开发变得轻松高效。结合图示和应用例子,主要介绍了Axis的工作原理、主要的相关技术WSDL,以及使用Axis时的环境设置、开发和部署Web服务的不同方法。     

Apache Axis1.1环境下WS-Security的研究与实现

SOAP构成了Web服务体系结构的通信基础，SOAP的扩展协议WS-Security是Web服务环境下最基础的安全协议，Apache Axis是Java平台上的一个开放源码的SOAP处理机。关于Web服务的安全性研究是Web服务在实际应用中所必须解决的问题。给出了一个基于WS-Security的安全模型，分析了Apache Axis的消息处理机制，研究了此模型在Apache Axis下的实现。     

基于Rampart实现SOAP消息安全

针对Web Services中日益突出的安全问题,本文将研究Axis2上SOAP消息的安全性,并利用Axis2的安全模块Rampart开发服务端和客户端的安全代码,Web Services应用添加一个WS—Security安全层,通过对SOAP消息的安全处理,实现Web Services的消息级安全。     

用Apache Axis开发Web服务

Apache Axis采用了完全开放和可插入的体系结构，把SOAP与Java相结合，使Web服务真正实现跨平台、跨语言。文中介绍了Apache Axis框架的关键部件、体系结构以及其处理SOAP消息的流程；并用实例阐述了以零起点方式开发和使用一个Web服务的全过程。     

基于SOAP技术构建Web服务的研究

简理分析了两个基于可扩展标记语言的技术：SOAP和WSDL的设计思想,并利用一个简单的实例，介绍了一种在Web服务开发过程中利用Tomcat和Axis自动编码、监听服务器和客户交互的方法。最后分析了在开发Web服务方面的几个有待解决的问题。     

基于JXTA的SOAP传输库的设计与实现

对等计算彻底地摒弃了"客户机/服务器"架构,克服了集中式计算的缺点.本文则致力于把Web服务这一项当前非常流行的技术引入P2P领域.P2P和Web服务的整合,充分利用了P2P的特点,克服了当前Web服务基于"客户机/服务器"计算模型的缺点,并使得在P2P 网络上使用其它对等点提供的服务变得更加简单和高效.为此,我们提出Project SOJN.Pr oject SOJN是使用JXTA和Apache Axis实现的基础类库,它使得SOAP消息可以在JXTA管道上面传输,并使对等点有了处理SOAP消息的能力.     

Web Services环境下基于私有UDDI的分布式系统研究

针对异构系统间交互性差的问题,研究了如何采用Axis构建一个基于Web Services的分布式信息系统,实现了分布式环境中基于XML的SOAP通信,通过WSDL文件实现服务器端和客户端的信息交互,将具体应用封装为服务的形式并配置私有UDDI服务器,实现服务的动态注册、发现,最终实现分布式环境下的资源共享与协同工作.     

基于Axis的服务端SOAP处理分析

Web Service是分布式计算领域出现的最新成果.SOAP作为Web Services的核心部分担负了其大部分工作,虽然有集成化的应用,但是目前对其内部处理的研究很少,难以使人对Web Services包含的技术有深入的理解,不利于技术灵活性和细节应用的拓展.本文在深入分析Axis的服务端SOAP处理机制的基础上,对SOAP模型进行讨论,拓展了Axis功能,以便能实现更复杂的处理模型.     

一种基于Axis2的SOAP安全传输模型的研究

目前Web服务体系架构存在标准限制且需要支持多种类型的客户端的问题,因而使得Web服务的安全极具挑战。SOAP构成了Web服务体系结构中的通信基础,WS-Security安全规范作为SOAP的扩展协议,是Web服务环境下最基础的安全协议。利用Apache Axis2结合Rampart组件实现了一个基于WS-Security的SOAP消息安全传输模型,从而为Web服务提供了一种消息级的安全解决方案。     

A portable interceptor mechanism for SOAP frameworks

An interceptor is a generic architecture pattern, and has been used to resolve specific issues in a number of application domains. Many standard platforms such as CORBA also provide interception interfaces so that an interceptor developed for a specific application can become portable across systems running on the same platform. SOAP frameworks are commonly used platforms to build Web Services. However, there is no standard way to build interceptors portable across current SOAP frameworks, although, some of them provide proprietary interceptor solution within individual framework, such as Axis, XFire, and etc. In this paper, we propose the portable interceptor mechanism (PIM) consisting of a set of application programming interfaces (API) on SOAP engine, a core component of a SOAP framework. An interceptor is able to receive messages passing through the SOAP framework from the SOAP engine via these APIs. Furthermore, the proposed PIM facilitates run-time lifecycle management of interceptors that is a crucial feature to many application domains but is not fully supported by CORBA standard. For concept proving, we implement the proposed PIM on two popular SOAP frameworks, namely, Axis and XFire. We also discuss a number of implementation issues including the performance and reliability of PIM.     

基于EJB的Web Service部署模型的研究

介绍了Web Service服务器的结构，分析和比较了JSR109基于EJB的Web Service部署模型和Axis基于EJB的Web Service部署模型，并根据项目要求实现了Web服务在Axis与Jboss组合Web Service服务器上的自动部署，有效地提高了部署效率。     

一种新型SOAP消息附件安全保障模型

随着Web服务的广泛应用和发展,提供安全保障能力是Web服务在商业应用中获得成功的关键因素。然而,目前还没有一种有效的方法对SOAP消息附件提供安全性支持。针对这一问题,本文提出了一种新型的SOAP附件安全保障模型,它可以在不改变客户端和服务器端内部实现的情况下,对附件进行加密和数字签名。在多中间节点的场景中,附件可以不经过任何中间节点从客户端直接发送到服务器,在减少附件被攻击可能性的同时提高了服务的执行效率。本模型在Web应用服务器上进行了原型实现,实验结果表明,该模型具有普遍性,可以高效地为企业提供附件安全保障。     

Redundancy-aware SOAP messages compression and aggregation for enhanced performance

Many organizations around the world have started to adopt Web services as well as server farms and clouds hosted by large enterprise and data centers for various applications. Web Services offer several advantages over other communication technologies. However, they have high latency and often suffer from congestion and bottlenecks due to the massive load generated by web service requests from large numbers of end users. SOAP (Simple Object Access Protocol) is the basic XML-based communication protocol of Web services. XML is a verbose encoding language in comparison with other technologies such CORBA and RMI. In this paper, two new redundancy-aware SOAP Web message aggregation models - Two-bit and One-bit XML status tree - are proposed to enable the Web servers to aggregate SOAP responses and send them back as one compact aggregated message in order to reduce the required bandwidth, latency, and improve the overall performance of Web services. XML message compressibility, the Jaccard based clustering technique, and the vector space model are three similarity measurements that are proposed to cluster SOAP messages as groups based on their similarity degree. The clustering based similarity measurements enable the aggregation techniques to potentially reduce the required network traffic by minimizing the overall size of the messages. The experiments show significant performance for both aggregation techniques achieving compression ratios as high as 25 for aggregated SOAP messages.     

Fault tolerant Web Services

Zwass suggested that middleware and message service is one of the five fundamental technologies used to realize Electronic Commerce (EC). The Simple Object Access Protocol (SOAP) is recognized as a more promising middleware for EC applications among other leading candidates such as CORBA. Many recent polls reveal however that security and reliability issues are major concerns that discourage people from engaging in EC transactions. We notice that the fault-tolerance issue is somewhat neglected in the current standard, i.e., SOAP 1.2. We therefore propose a fault tolerant Web Services called fault tolerant SOAP or FT-SOAP through which Web Services can be built with higher resilience to failure. FT-SOAP is based on our previous experience with an object fault tolerant service (OFS) and OMG’s fault tolerant CORBA (FT-CORBA). There are many architectural differences between SOAP and CORBA. One of the major contributions of this work is to discuss the impact of these architectural differences on FT-SOAP design. Our experience shows that Web Services built on a SOAP framework enjoy higher flexibility compared to those built on CORBA. We also point out the limitations of the current feature sets of SOAP 1.2, e.g. the application of the intermediary. In addition, we examine two implementation approaches; namely, one based on the SOAP 1.2’s intermediary, and the other on Axis handler. We conclude that the intermediary approach is infeasible due to the backward compatibility issue. We believe our experience is valuable not only to the fault-tolerance community, but also to other communities as well, in particular, to those who are familiar with the CORBA platform.