JAD (Java Application Descriptor File)
The JAD Misc file format
The JAD file extension stands for Java Application Descriptor File. This is a very specific type of file that is specifically used in Java ME applications. These are commonly used to create and run applications that have a purpose of working on mobile devices, describing the content if a so-called MIDlet. There are not many programs that have the ability to use this file, so if you are trying to run a program or a game that uses this type of file on a device it wasn’t originally intended for, you may have problems and will have to convert the JAD file to a different extension before it will function properly.
Technical details of JAD files
JAD files are primarily used for mobile applications and for games that are used on mobile phones. These files give the phone the ability to interact with other types of online web services. This includes the ability to send SMS messages and also gives game players the ability to interact with other game players. A few BlackBerry mobile devices make use of files using the JAD extension for the themes on their devices. Recent technology allows the MIDlet to contain a manifest. This manifest has the ability to hold a great deal of the information previously held in the JAD file, so the use of this type of file is being reduced.