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 - accessing the PersistentObject data


  1. 1. Add the following code to the JournalEntryMainScreen constructor under the call to getPersistentObject that we just added.

    if (JournalStoreObject.getContents() == null)
    {
    _EntryList = new Vector();
    }
    else
    {
    _EntryList = (Vector)JournalStoreObject.getContents();
    }
    

What just happened?

This last baby step is where you actually get the data from the PersistentObject that you had previously got. The most important things to notice here is that you have to check to see if the contents of the PersistentObject are set to NULL. If they are, then you simply create a new Vector in the typical fashion. If not though, the _EntryList member is set to the contents of the PersistentObject after being cast to the proper type first.

This code replaces the enumeration and looping that you did for RMS in order to load each entry in the list. Because you are loading the entire Vector, and not just individual JournalEntry objects, there is no need to loop...