Enterprise J2ME Developing Mobile Java Applications [Electronic resources] نسخه متنی

Chapter 4. Managed Smart Clients

CHAPTER OVERVIEW

Container-Managed Mobile Clients

OSGi Containers

OSGi Bundle Interactions

IBM Service Management Framework

A Simple Echo Service Example

Smart Client with HTTP Front End

The Pizza Order Example

Mobile Gateways

In Chapter 3, we discussed the smart client paradigm. However, for complex mobile applications, monolithic clients with intertangled code segments are very hard to develop and maintain. We need a framework to develop modularized application and service components. In this chapter, we introduce the concept of managed smart clientsself-contained components inside software containers. The container provides common crosscutting services and a framework for components to communicate with each other. The industry standard for lightweight mobile containers is the OSGi (Open Services Gateway initiative) specification. Using several example OSGi applications running on IBM Service Management Framework, we explain how OSGi-managed smart clients work in real-world applications. In addition to supporting managed clients, OSGi applications can also deliver mobile gateway services. We will cover the gateway architecture near the end of this chapter.