Java ME
Getting Hands On to Java ME

Writing a Java ME application is different fromwriting the classical java application. Though it uses the same basics programming constructs as used with Java SE applications. Java ME platform provides a better space to develop games and applications for small devices like PDA’s and handheld devices. Basically there are two types of configurations involved in Java ME application development which are:
  • CLDC (Connected Limited Device Configuration)
  • CDC (Connected Device Configuration)

Java ME architecture consists of layers highly compatible with the native environment (i.e. OS) of the device. These layers are collectively known as the Connected Limited Device Configurations (CLDC). The CLDC installed on the OS forms a tine environment for small computing device. The Java ME Architecture comprises of three software layers:
  • The first layer is the configuration layer that includes the JVM, which directly interacts with the native OS. The Configuration layer also handles the interaction between the profile and the JVM.
  • The second layer is the profile layer which consists of the minimum set of application programming interface (API) for the small devices.
  • The third layer is the Mobile Information Device profile (MIDP) layer. The MIDP layer contains java APIs for user network connections, persistence storage, and the user interface. It also has access to CLDC libraries and MIDP libraries.

Connected Limited Device

Configuration (CLDC): This Configuration is much popular among the developers community to build the Java ME applications. CLDC defines

the core set of API and a virtual machine for resource-constrained devices like mobile phones, pagers, and mainstream personal digital assistants.. There are two versions of CLDC: First one is CLDC1.0 which was released in 2000 and very soon it was termed as Java Specification Request (JSR) 30. Second one is CLDC1.1 or more specifically as JSR 139 However 1.0 is much popular in use. When CLDC is coupled with a profile such as the Mobile Information Device Profile (MIDP), it provides a solid Java platform for developing applications to run on devices with limited memory, processing power, and graphical capabilities.

Connected Device Configuration (CDC): Developed under the Java Community Process (JCP), it is a standard framework of Java technology used for building and delivering application that can be shared over a wide range of networks and devices ranging from pagers, mobile phones, set top boxes and other PDA devices. It comes in two flavors: First one is JSR 36 (CDC 1.0) and second one is JSR 218 (CDC 1.1).

Mobile Information Device Profile (MIDP): The MIDP specification was defined through the Java Community Process (JCP) by an expert group of more than 50 companies, including leading device manufacturers, wireless carriers, and vendors of mobile software. MIDP provides a standard Java runtime environment for various mobile devices. It defines a platform for dynamically and securely deploying optimized, graphical, networked applications.

MIDP, when combined with the CLDC, provides the Java runtime environment for the compact mobile information devices, such as cell phones and mainstream PDAs. Developers can develop application once and then redistribute them into various mobile information devices in a very small period of time with help of MIDP. Its principal functions include to provide the user interface, network connectivity data storage and overall application process management. The Mobile Information Device Profile (MIDP) is a key element of the Java Platform, ME.

There are two versions of MIDP:
First one MIDP 2.0 or JSR 118 and second one MIDP 1.0 or JSR 37.

Oct 2007 | Java Jazz Up | 16
Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,

, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53 , 54, 55, 56, 57,

, 59, 60, 61, 62, 63 , 64, 65 , 66 , 67 , 68 , 69 , 70, 71, 72, 73, 74, 75, 76, 77, 78,   Download PDF