Mapping service components to EJB business objects

The emerging trends for e-business engineering revolve around specialisation and cooperation. Successful companies focus on their core competencies and rely on a network of business partners for the support services required to compose a comprehensive offer for their customers. Modularity is crucial for a flexible e-business infrastructure, but related requirements seldom reflect on the design and operational models of business information systems. Software components are widely used for the implementation of e-business applications, with proven benefits in terms of system development and maintenance. We propose a service-oriented componentisation of e-business systems as a way to close the gap with the business models they support. Blurring the distinction between external services and internal capabilities, we propose a homogeneous model for the definition of e-business applications components and present a process-based technique for component modelling. We finally present an Enterprise Java Beans extension that implements the model

Web-course search engine : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Computer Science at Massey University

The World Wide Web is an amazing place that people's lives more and more rely on. Especially, for the young generation, they spend a significant amount of their play and study time using the Internet. Many tools have been developed to help the educational users in finding educational resources. These tools include various search engines. Web directories and educational domain gateways. Nevertheless, these systems have many weaknesses that made them unsuitable for the specific search needs of the learners. The research presented in this thesis describes the development of the Web-course search engine, which is a friendly, efficient and accurate helper for the learners to get what they want in the vast Internet ocean. The most attractive feature of this system is that the system uses one universal language, which lets the searchers and the resources "communicate" with each other. Then the learner searchers can find the Web-based educational resources that are most fit to their needs and course providers can provide all necessary information about their courseware. This universal language is one widely acceptable Metadata standard. Following the Metadata standard, the system collects exact information about educational resources, provides adequate search parameters for search and returns evaluative results. By using the Web-course search engine, the learners and the other educational users are able to find useful, valuable and related educational resources more effectively and efficiently. Some improvement suggestions of the search mechanism in the World Wide Web have been brought forward for the future research as a result of this project

Using real options to select stable Middleware-induced software architectures

The requirements that force decisions towards building distributed system architectures are usually of a non-functional nature. Scalability, openness, heterogeneity, and fault-tolerance are examples of such non-functional requirements. The current trend is to build distributed systems with middleware, which provide the application developer with primitives for managing the complexity of distribution, system resources, and for realising many of the non-functional requirements. As non-functional requirements evolve, the `coupling' between the middleware and architecture becomes the focal point for understanding the stability of the distributed software system architecture in the face of change. It is hypothesised that the choice of a stable distributed software architecture depends on the choice of the underlying middleware and its flexibility in responding to future changes in non-functional requirements. Drawing on a case study that adequately represents a medium-size component-based distributed architecture, it is reported how a likely future change in scalability could impact the architectural structure of two versions, each induced with a distinct middleware: one with CORBA and the other with J2EE. An option-based model is derived to value the flexibility of the induced-architectures and to guide the selection. The hypothesis is verified to be true for the given change. The paper concludes with some observations that could stimulate future research in the area of relating requirements to software architectures

Scala Server Faces

Progress in the Java language has been slow over the last few years. Scala is emerging as one of the probable successors for Java with features such as type inference, higher order functions, closure support and sequence comprehensions. This allows object-oriented yet concise code to be written using Scala. While Java based MVC frameworks are still prevalent, Scala based frameworks along with Ruby on Rails, Django and PHP are emerging as competitors. Scala has a web framework called Lift which has made an attempt to borrow the advantages of other frameworks while keeping code concise. Since Sun’s MVC framework, Java Server Faces 2.0 and its future versions seem to be heading in a reasonably progressive direction; I have developed a framework which attempts to overcome its limitations. I call such a framework ―Scala Server Faces‖. This framework provides a way of writing Java EE applications in Scala yet borrow from the concept of ―convention over configuration‖ followed by rival web frameworks. Again, an Eclipse tool is provided to make the programmer\u27s task of writing code on the popular Eclipse platform. Scala Server Faces, the framework and the tool allows the programmer to write enterprise web applications in Scala by providing features such as templating support, CRUD screen generation for database model objects, an Ant script to help deployment and integration with the Glassfish Application Server

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

Monitoring extensions for component-based distributed software

This paper defines a generic class of monitoring extensions to component-based distributed enterprise software. Introducing a monitoring extension to a legacy application system can be very costly. In this paper, we identify the minimum support for application monitoring within the generic components of a distributed system, necessary for rapid development of new monitoring extensions. Furthermore, this paper offers an approach for design and implementation of monitoring extensions at reduced cost. A framework of basic facilities supporting the monitoring extensions is presented. These facilities handle different aspects critical to the monitoring process, such as ordering of the generated monitoring events, decoupling of the application components from the components of the monitoring extensions, delivery of the monitoring events to multiple consumers, etc.\ud The work presented in this paper is being validated in the prototype of a large distributed system, where a specific monitoring extension is built as a tool for debugging and testing the application behaviour.\u

An Overview and Comparison of Three Major Enterprise Application Development Platforms

This paper presents an overview and comparison of three major industrial-strength enterprise application development (and deployment) platforms. The platforms are Microsoft.Net, Java 2 Enterprise Edition, and WebObjects. The comparison includes discussion of the presentation tier, application tier, persistence tier, deployment, and tools. Although not a complete survey and somewhat subjective in its final recommendations, the paper should provide a general understanding of these three major platforms and how they compare. The choice of development platform is a significant one for developers and organisations (because they generally have a significant learning curve)and should not be made without a good understanding of the alternatives

Web-based distributed EJB BugsTracker: an integration of struts framework at web server, EJBs at application server, and a relational database

This Web-based Distributed EJB BugsTracker is an integration effort of the 4-tier Enterprise Java Bean -- EJB component architecture where it uses a web browser, a web server, an application sever, and a relational database server. The application is designed and built for software managers, engineers and quality assurance staffs that keep track of the software defects which are produced during the software development life cycle. It allows independent user login in multi-project environments. This project makes use of all the benefits of the J2EE technologies: maintainability, portability, and scalability. In addition, Container Managed Persistence (CMP 2.0) greatly simplifies the connection between the application and the database tiers which results in developing a portable application that is database-independent

Performance Testing of Distributed Component Architectures

Performance characteristics, such as response time, throughput andscalability, are key quality attributes of distributed applications. Current practice,however, rarely applies systematic techniques to evaluate performance characteristics.We argue that evaluation of performance is particularly crucial in early developmentstages, when important architectural choices are made. At first glance, thiscontradicts the use of testing techniques, which are usually applied towards the endof a project. In this chapter, we assume that many distributed systems are builtwith middleware technologies, such as the Java 2 Enterprise Edition (J2EE) or theCommon Object Request Broker Architecture (CORBA). These provide servicesand facilities whose implementations are available when architectures are defined.We also note that it is the middleware functionality, such as transaction and persistenceservices, remote communication primitives and threading policy primitives,that dominates distributed system performance. Drawing on these observations, thischapter presents a novel approach to performance testing of distributed applications.We propose to derive application-specific test cases from architecture designs so thatthe performance of a distributed application can be tested based on the middlewaresoftware at early stages of a development process. We report empirical results thatsupport the viability of the approach