JAD initiated installation process overview

This page describes the overall process of how a MIDlet or MIDlet suite is installed onto a Symbian OS phone when a JAD is supplied.

The Installer is initiated by the user selecting the JAD file. This may happen by the user clicking on the JAD in a web or WAP browser, or on an email attachment or clicking on a JAD file supplied to the phone using some other transfer protocol, e.g. via IR, Bluetooth etc. In any case the Symbian OS Recogniser ensures that the Installer is started when presented with a JAD file. The JAD file is downloaded and parsed. The JAD contains the information needed for installation. During installation the Installer:

1. Carries out the following in no specific order:

   • Examines the MicroEdition-Configuration and MicroEdition-Profile attributes, if they are present. The versions required by the suite are compared with the versions supported, and if unsuitable the user is notified and the Installer does not proceed.

   • Displays details of the software to the user, requesting confirmation that the installation should continue. Details include the Vendor, the Name and the Version of the MIDlet and, if one has been provided in the JAD file, a description.

   • Compares the MIDlet-Name, MIDlet-Version, and MIDlet-Vendor with the corresponding attributes of all the MIDlet suites installed on the phone. If the MIDlet-Name and MIDlet-Vendor are the same as a suite already installed, the user is prompted whether to overwrite the existing version.

2. Gives the user choice of drive to install the MIDlet and the option to proceed with, or cancel, the installation. The attributes MIDlet-Jar-Size, and MIDlet-Data-Size are used to display information to the user on the required amount of disk space.

3. Examines the MIDlet-Jar-URL attribute. The process supports HTTP:// and File:// (the default). If the URL is not in either format, the user is notified with a dialog displaying Invalid download location, and the Installer does not proceed.

4. Downloads the JAR file from the given URL and places it on the phone.

5. Parses the manifest of the downloaded JAR and checks that the values of the MIDlet-Name, MIDlet-Version, and MIDlet-Vendor attributes are identical to those of the JAD. If they are not, the user is notified, the JAR and JAD files are deleted from the phone and the Installer does not proceed.

   The attributes MicroEdition-Profile and MicroEdition-Configuration are examined and the versions required by the suite are compared with the versions supported, and if unsuitable the user is notified and the Installer does not proceed. This test is the same as the one of step 1 but the attributes MicroEdition-Profile and MicroEdition-Configuration are optional in the JAD but required in the JAR's manifest.

6. Copies the JAD and JAR files to to \Private\102033E6\MIDlets\<UID>\, where 102033E6 is a private directory named after the UID of the Java Virtual Machine (JVM) and UID is a unique identifier provided at installation.

7. If an upgrade fails, the previous version continues in use.

This completes the MIDlet installation process.