Foreword. Greg Papadopoulos, CTO Sun Microsystems, Inc; SECTION 1; Getting started; The development tools including a look at the SDK, emulator and Java tools. Compiling a Hello World program and deploying a program on target devices; The Crystal Communicator reference design; An introduction to Crystal, the Crystal APIs and design considerations. Command button arrays, the virtual cursor, Crystal Toolkit APIs and putting it all together; The Quartz Communicator reference design; An introduction to Quartz, the anatomy of a Quartz application, APIs and tuning Java applications for Quartz; SECTION 2; PersonalJava; Summary of PersonalJava, a look at the Symbian implementation of PersonalJava, the timer classes and example, the capability interfaces, what they are and how they relate to Quartz and Crystal reference designs; JavaPhone; The JavaPhone architecture and working with JavaPhone, conventions, JavaPhone on the Symbian OS, the APIs and resources; Games; Models for games, multiplayer games, separation of distinct engine parts. Strategy games and action games design issues, platform constraints. Case-study: wireless four player Whist, with example code; UI Guidelines; A round-up of Symbian devices and how they support Java. Creating a user interface that works, writing applications that look good and work well on constrained devices; Optimization; Guidelines for optimization, tools for optimization, and enhancing Java s performance. Design patterns, memory management and what s next in enhancing Java performance on WIDs; SECTION 3; Creating Wireless Services; Understanding the needs and wants of service providers and network operators, and how Java fits in with these. Benefits and limits of Java on WIDs, opportunities, security and application delivery; Security; Developing a secure environment, the components necessary to create a secure environment, Symbian OS v6.0 security capabilities and security management in the future; Provisioning; The MID Profile, Applets,the Java service provisioning manager, Java Web Start, MExE -iBus//Mobile messaging service; Case Studies; Two case studies from the wireless community: the Simple Conference Service is an example of a chat/draw service from Digia Oy, a Symbian Competence Center; and the Handheld Travel Assistant ,a location-based mapping service from Telenor R SECTION 4; JNI Programming; What is the Java Native Interface? JNI and the Symbian OS, the build environment for JNI projects and troubleshooting tips; Looking to the Future; Beyond Symbian OS v6,J2ME technologies, Jini, MExE and WAP.