The Complete Reference J2ME

Introduction

Java technology has evolved from a programming language designed to create machine-independent embedded systems into a robust, vendor-independent, machine-independent, server-side technology, enabling the corporate community to realize the full potential of web-centric applications.

Java began with the release of the Java Development Kit (JDK). It was obvious from the start that Java was on a fast track to becoming a solution to the problems of many corporate systems. More interface and libraries were extended in the JDK as the corporate world demanded—and received—application programming interfaces (API) that addressed real-world situations.
JDK API extensions fully integrated into the JDK with the release of the Java 2 Standard Edition (J2SE) of the JDK. J2SE contains all the APIs needed to build industrialstrength Java applications. However, the corporate world felt J2SE lacked the strengthrequired for developing enterprise-wide applications and for servicing the needs of developers of mobile and embedded systems.

Again the corporate community pushed Sun Microsystems, Inc. to revise Java technology to address needs of an enterprise. Sun Microsystems, Inc. then launched the Java Community Program (JCP) that brought together corporate users, vendors, and technologists to develop a standard for enterprise Java APIs. The result is the Java 2 Platform Enterprise Edition, commonly referred to as Java 2 Enterprise Edition (J2EE), and the Java 2 Micro Edition (J2ME). Enterprise systems traditionally are designed using the client/server model, where client-side systems request processing from service-side systems. However, enterprise systems were undergoing their own evolution. Anew model calledWeb services gradually replaced the client/server model in corporations. Application programmers assembled applications from an assortment of processing
components called Web services. Each Web service was independent from other Web services and independent from applications. A client-side application communicates with a middle-tier, server-side application, which in turns interacts with the necessary Web services that are also located on the server side.
With the adoption of the Web services model in corporations, the JCP realized that J2ME must also go through another evolutionary cycle. With the introduction of new specifications, the Java community has merged J2ME technology with Web services technology. In addition to the acceptance ofWeb services, corporations are also seeking to merge mobile technology such as Personal Digital Assistants and cellular phones with corporate mainstream applications. J2ME, with the new PIM API, enables developers to create sophisticated, wireless applications that have direct access to native PDA databases. This enables corporate executives to use corporation’s PDA systems to interact with data mantained by PDA native applications.

What’s Inside

This book covers in detail all aspect of J2ME, Web services, PDA, and cellular phone application development. The book is divided into these five parts:

■ Part I: J2ME Basics
■ Part II: J2ME User Interface
■ Part III: J2ME Data Management
■ Part IV: J2ME Personal Information Manager Profile
■ Part V: J2ME Networking and Web Services

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