| NetBeans Mobility Pack makes it easy for all programmers to start development of Java ME applications quickly, even if you have had only Java SE programming experience. If you are trying out mobile application programming for the first time, you can just think of Java ME as having a more limited version of the Java SE API and let NetBeans Mobility Pack take care of the foreign Java ME issues. Although there are more differences than just a smaller API, it's not necessary to know all the intricacies before producing a working mobile application. To help you get started, here are some terms that are used throughout this document: Java ME. Java Platform, Micro Edition, is the Java platform meant to run on small devices. Currently, these devices are typically cell phones or PDAs, but Java ME is also used on other embedded systems. A configuration, a profile, and optional packages are what compose a Java ME platform. CLDC. Connected Limited Device Configuration is a Java ME configuration that is currently most often used on mobile phones. It contains a runtime environment and a core API that are appropriate for the limited processor speed and memory size of mobile devices. MIDP. Mobile Information Device Profile is the set of APIs that provides higher-level functionality required by mobile applications, such as displayable components ("screens") and network communication. MIDlet. A class required by all MIDP applications. It acts as the interface between the application and the device on which it is running. A MIDlet is similar to a main class in a J2SE project. Preverification. When building an application that runs with CLDC, all compiled classes must be preverified. Preverification is a process that adds annotations used by the CLDC JVM to a class file's bytecode. The preverification process also ensures that the class contains only code that will run on its CLDC version. Device fragmentation. Term used for the variations between mobile platforms that prevent a single application from automatically running optimally on all phones. These differences can be physical (screen size, screen color depth, available memory, and so on) or software related (available APIs, CLDC/MIDP version, and so on). Preprocessor. NetBeans Mobility Pack ships with a preprocessor that is used as part of its device fragmentation solution. The preprocessor is an Ant task that runs before files are compiled. It looks for special Java comment tags within the file and adds or removes line comments based on these tags. Obfuscation. A process that makes class files difficult to reverse-engineer. This is usually accomplished by, at least, replacing names of packages, classes, methods, and fields with short identifiers. This also has the result of decreasing the size of your application and, therefore, is an important aspect of the mobile application build process.
If you're interested in learning more, countless online and offline resources are available. A good place to start looking is http://java.sun.com/j2me/. |
