Once the right tools on your computer have been installed, Blackberry mobile applications can be easily developed. These tools include: a Java Software Development Kit (JDK) and a BlackBerry Java Development Environment (JDE). You can download these tools at zero cost from the Sun Microsystems and Research In Motion websites. The JDK is packed with the basic tools for compiling Java source code into the bytecode used by the Java interpreter. The JDK also offers the Java Interpreter, used to run a number of development tools in the JDE.
The JDE provides the BlackBerry-specific tools for converting Java bytecode into the special format used by the Java-like interpreter on BlackBerry handhelds. It also provides the debugging and editing tools needed for software development. You must begin by deciding the version of the Blackberry operating system (OS) you want to target. This determines the version of JDE you need to use. This in turn helps in determining the version of the JDK required to be installed.
The basic rule is that you must always use a JDE version equal to or less than the OS version you wish to target. To be on the safe side, you need to use the accurate version of JDE for the final builds of your application even when you are using a different JDE version for interim development. Once you have installed the right JDK, you can download and install the desired JDE from the Blackberry developer site. For this you will need to register for an account on the site. However, you needn’t pay charges for this. You must also ensure that you join RIM’s Blackberry developer program. There are a number of versions of JDE and the JDK. These versions can co-exist on the same machine and present no problems at all if you install them in the right order.