Book Image

BlackBerry Java Application Development

Book Image

BlackBerry Java Application Development

Overview of this book

BlackBerry Smartphone was once the domain of jet-setting business users with power suits. Now you can hardly go anywhere without seeing someone using a BlackBerry to check their messages or make a call. It's this kind of explosive growth that makes the BlackBerry ecosystem a great place to develop and market applications through the BlackBerry App World store—this book shows you how to do just that! This step-by-step guide gives you a hands-on experience of developing innovative Java applications for your BlackBerry. With the help of this book, you will learn to build your own applications to illustrate the platform, and the various capabilities that developers can use in their programs. It explores the powers of Blackberry and helps you develop professional and impressive Java applications. The book teaches how to write rich, interactive, and smart BlackBerry applications in Java. It expects the readers to know Java but not Java Mobile or the BlackBerry APIs. We will learn to build rich, interactive, and smart Java applications for the BlackBerry. The book will cover UI programming, data storage, programming network, and internet API apps. As we move on, we will learn more about the BlackBerry's device features, such as messaging, GPS, multimedia, contacts and calendar, and so on.This book also helps you build your own applications to illustrate the platform, and the various capabilities that developers can use in their programs.
Table of Contents (18 chapters)
BlackBerry Java Application Development
Credits
About the Author
Acknowledgement
About the Reviewers
Preface

Time for action - preparing the JournalEntry class


The one requirement for storing your own custom classes in the PersistentStore is that the class (and any other classes that it might contain) must implement the Persistable interface. So let's do that now. Replace the JournalEntry class declaration with the following one and you will be set up to store the JournalEntry objects in the PersistentStore.

public class JournalEntry implements Persistable

What just happened?

Implementing the Persistable interface couldn't be any easier! The interface itself has no methods in it so there is no code to write besides creating the implements specification itself. How easy is that?

You have to do this only for your own custom classes. Primitive data types as well as some common data structures, such as Vector, are already handled automatically. However, if your data structure is complex, you will need to add the interface declaration to each class which is included as well as the main class that contains...