BlackBerry and Java have a long and storied history together. Since the launch of the BlackBerry 5810 in 2002, all BlackBerry smartphones have been Java-based. All core BlackBerry applications have been written in Java. As you can see, there are many benefits to being familiar with Java, especially as it pertains to being a BlackBerry developer.
The BlackBerry platform is different from most mobile platforms in that it enables your applications to continue running in the background or in sleep mode. The server-side push technology is another advanced feature that allows more seasoned developers to utilize true mobile OS multitasking to produce original and dynamic apps.
The BlackBerry site has a series of developer labs and tutorials intended to teach developers the ins and outs of this more advanced programming capability. After all, the BlackBerry platform is a multi-threaded environment, so it would be incredibly wise for a person interested in advanced Java programming to learn how to build background applications that are capable of doing data processing and listening for push data.
The lab, which is entitled “Listening for pushed data,” covers the essentials of creating auto-start background apps, which will act as push listeners. Developers will also learn how those apps effectively communicate with other apps on the BlackBerry smartphone device. A developer who’s at ease with advanced Java programming should be able to create separate threads for background tasks, open a connection to listen for pushed data, display pushed data on the user interface, and use the Mobile Data System simulator for testing.
Bluetooth Peripherals
The introduction of Bluetooth functionality with BlackBerry smartphone devices proved to be a major stepping stone for BlackBerry and it also gave developers a wide array of new possibilities for their applications. Though this type of integration is obviously an advanced Java programming feature, it’s easier than one would immediately think. Any design app that extends to various kinds of Bluetooth hardware, such as headsets, printers, writing devices, and GPS transmitters is incredibly welcomed. Both the Java environment and Bluetooth protocols follow industry standards, so integrating any Bluetooth device with a BlackBerry smartphone shouldn’t be too difficult for a seasoned developer.
For programming, there is wide support for Serial Port Profile (SPP) and JSR 82, which defines the Object Exchange Profile (OBEX) and Object Push Profile (OPP). Using OBEX and OPP, other profiles can be built, such as the Human Interface Device Profile (HID).
Smartphone Development 
