4
Downloading
Applications
20
4
Downloading Applications
Method of Downloading
The option open to the developer for deploying the MIDlet to a physical Motorola device is
OTA (over -the-air) downloading.
OTA
To use the OTA method, the developer will have a connection through a wireless network
to a content server. This content server could be, for example, Apache
(http://httpd.apache.org
) which is free to use, deployable on multiple operating systems,
and has extensive documentation on how to configure the platform.
The required file will be downloaded (either .jad and/or .jar) by issuing a direct URL
request to the file in question or it could be a URL request to a WAP page and a hyperlink
on that page to the target file. This request will be made through the OPERA Browser. In
MIDP 2.0, the need for a JAD file before download is not required, so the JAR file can be
downloaded directly. The information about the MIDlet will be pulled from the manifest file.
The transport mechanism used to download the file will be one of two depending on the
support from the network operators WAP Gateway and the size of file requested.
HTTP Range – see specification RFC 2068 at
http://www.rfc-editor.org/rfc.html
if
content greater than 30k in size. Below is a ladder diagram showing the flow
through HTTP range transfer, although recall use of the .JAD is optional.
SAR (Segmentation & Reassembly) – see specification of wireless transaction
protocol at the
http://www.wapforum.org
if less than 100k in size.
During a download of the application, the user will see the OPERA browser displaying a
progress dialog.
A complete guide for setting up an OTA server can be obtained through the
MOTOCODER website (
http://www.motocoder.com
). This includes details of configuring
the server and also example WAP pages.
The following error codes are supported:
900 Success
901 Insufficient Memory
902 User Cancelled
903 Loss Of Service