This book helps experienced Java developers to build high-value mobile applications that take advantage of enterprise IT infrastructure. After a comprehensive analysis of the landscape and trends of the J2ME platform, the book uses the source code of several award-winning, real-world applications to illustrate the design, architecture and best practices of end-to-end smart phone solutions. Then this book focuses on four areas most important business applications: Converged messages (email, IM, mobile P2P as well as enterprise messaging middleware); data management (mobile and backend relational databases), ubiquitous integration (mobile Web services) and security Sophisticated (J2ME cryptography). Over 300 code listings from the sample applications (available for download from the web site the book) is used to illustrate the application designs, coding techniques and the use of third-party tools.