Overview of installing, running and removing MIDlets

This document summarises the process of installing, running and removing MIDlets on Symbian OS.

MIDlets are normally delivered as a package of files called a MIDlet suite. This contains a JAR (Java Archive) and a JAD (Java Application Descriptor) file. These files may be delivered to the phone through a web or WAP browser, as an email attachment, or they may be transferred using infrared or Bluetooth; the latter two methods are most commonly used during development and testing.

MIDlets are installed by selecting their JAD file, which starts the native Symbian OS Installer. The JAD file is downloaded and parsed. From this file, the Installer reads the URL for the MIDlet's JAR, checks that enough space is available on the phone, and then downloads the JAR. This process is described in JAD initiated installation process overview. After some checks by the Installer, the MIDlet is installed onto the phone.

The Installer automatically creates the native application files needed for presenting and launching the MIDlet in the same way as a native C++ application, see Application files for presenting and running MIDlets.

The process is similar, but with some minor differences, when no JAD file is supplied. See JAR initiated installation process overview for details.

Once installed, the MIDlet appears in the phone's application launcher among the other applications. The MIDlet is launched in the same way as the native applications, by selecting its icon.

When the MIDlet is launched, the Symbian OS Recogniser checks to see if it is a valid application and then executes it.

After installation, MIDlets and MIDlet suites may be removed using the phone's standard application removal system. All MIDlets within a suite are removed together. All the files and directories that were created during the installation of the MIDlet are removed. See Removal of installed MIDlets.