Java ME Terminology
From Symbian Developer Community
This section covers some of the more common terms encountered when working with Java ME on the Symbian platform:
| AMS | The application management system. The part of the device’s operating system responsible for controlling a MIDlet’s life-cycle, performing security checks, installation and removal of MIDlet suites and their data (RMS stores). |
| CLDC | The connection limited device configuration. This defines a minimal set of basic functionality and sits underneath a profile such as MIDP. As a developer, you use the APIs that it defines through a profile transparently , so you don’t really need to worry about it at this stage. |
| Feature phone | This term is loosely used in industry to refer to lower-end mass-market devices. It isn’t a fixed definition but tends to refer to those devices with cheaper hardware, slower processors and less memory than used in typical Symbian devices. It is also used to refer to devices that generally do not allow native applications to be installed after market. |
| Fragmentation | Refers to variations in the presence or quality of a set of JSRs across mobile device hardware. Fragmentation has caused many development companies to maintain many different branches of their core code base, in order to target as many mobile devices as possible. Initiatives such as the JTWI and the MSA (defined below) are designed to attempt to address fragmentation. |
| JAD | Java application descriptor file. A plain text file used to supply mandatory attributes that describe a MIDlet suite. This allows OTA (see below) deployment and provides a standard way for MIDlets to declare their use of restricted APIs. |
| JAR | Java archive file. This is a package of Java class files and resources that can be deployed to a device (via Bluetooth, cable or PC suite) and executed directly by the Java runtime. |
| Java Reflection API | Reflection is a way to query an object at runtime and discover information such as what interfaces it implements, the names and parameters of any methods it has, what type it is and so on. Using reflection makes it possible to query runtime details of an object and invoke its methods without prior knowledge of class details. |
| JCP | The Java community process. A group of interested parties from industry, academia and even individuals that collaborate to define the specification for each JSR. |
| JSR | A Java specification request (made through the JCP0. When finalised, a JSR defines the behavior to which an implementation must adhere. |
| MIDlet | A Java ME application that is written to the MIDP specification |
| MIDlet Suite | A set of MIDlets can be bundled together in a single JAR/JAD combination. MIDlets in the same suite can share their data stores by default. |
| MSA/JTWI | The Mobile Services Architecture and the Java Technology for the Wireless Industry standards. Designed to combat fragmentation of JSRs across the device spectrum and provide a consistent platform that developers can target |
| OTA | Deployment over the air. MIDlets can be downloaded directly on to a device from a website, for example. The AMS will detect this, run security checks and, if all is well, initiate the installation process on the device. This process requires a JAD file to work correctly. |
| RMS | The record management store. This is an API that defines how MIDlets can persist application data on mobile devices. It provides a simple byte-array-based set of records with basic search and management operation. The details of how this is achieved are left to the manufacturer. |
| Smartphone | A general term used to indicate a handset that runs a more advanced operating system, such as a Symbian device. |
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