Secure Web Service Clients on Mobile Devices

Enterprise apps on mobile devices typically need to communicate with other system components by consuming web services. Since most of the current mobile device platforms (such as Android) do not provide built-in features for consuming SOAP services, extensions have to be designed. Additionally in order to accommodate the typical enhanced security requirements of enterprise apps, it is important to be able to deal with SOAP web service security extensions on client side. In this article we show that neither the built-in SOAP capabilities for Android web service clients are sufficient for enterprise apps nor are the necessary security features supported by the platform as is. After discussing different existing extensions making Android devices SOAP capable we explain why none of them is really satisfactory in an enterprise context. Then we present our own solution which accommodates not only SOAP but also the WS-Security features on top of SOAP. Our solution heavily relies on code generation in order to keep the flexibility benefits of SOAP on one hand while still keeping the development effort manageable for software development. Our approach provides a good foundation for the implementation of other SOAP extensions apart from security on the Android platform as well. In addition our solution based on the gSOAP framework may be used for other mobile platforms in a similar manner.

Event Monitoring Web Services for Heterogeneous Information Systems

Heterogeneity has to be taken into account when integrating a set of existing information sources into a distributed information system that are nowadays often based on Service- Oriented Architectures (SOA). This is also particularly applicable to distributed services such as event monitoring, which are useful in the context of Event Driven Architectures (EDA) and Complex Event Processing (CEP). Web services deal with this heterogeneity at a technical level, also providing little support for event processing. Our central thesis is that such a fully generic solution cannot provide complete support for event monitoring; instead, source specific semantics such as certain event types or support for certain event monitoring techniques have to be taken into account. Our core result is the design of a configurable event monitoring (Web) service that allows us to trade genericity for the exploitation of source specific characteristics. It thus delivers results for the areas of SOA, Web services, CEP and EDA.

Event Monitoring Based On Web Services for Heterogeneous Event Sources

This article discusses event monitoring options for heterogeneous event sources as they are given in nowadays heterogeneous distributed information systems. It follows the central assumption, that a fully generic event monitoring solution cannot provide complete support for event monitoring; instead, event source specific semantics such as certain event types or support for certain event monitoring techniques have to be taken into account. Following from this, the core result of the work presented here is the extension of a configurable event monitoring (Web) service for a variety of event sources. A service approach allows us to trade genericity for the exploitation of source specific characteristics. It thus delivers results for the areas of SOA, Web services, CEP and EDA.

Shopping Cart System: Load Balancing and Fault Tolerance in the OSGi Service Platform

The main purpose of this paper was to find a simple solution for load balancing and fault tolerance in OSGi. The challenge was to implement a highly available web application such as a shopping cart system with load balancing and fault tolerance, without having to change the core of OSGi.