Motorola J2ME Specifications download pdf (Page 18)

Launching Web Session for HTTP Download

The Web Sessions implementation will be modified to allow the user to download Java

content using an HTTP server instead of a WAP gateway. The user will then need to enter

a Web Session from the Web Sessions menu.

Downloading MIDlets

The Browser must be connected before the series of handsets is able to download any

MIDlets. The user may access the Browser application by any of the following methods:

• Selecting “Browser” from the Main Menu

• Selecting a URL from a message

Once the series of handsets is connected to the WAP browser, different locations may be

visited where J2ME Applications can be downloaded. From here, a MIDlet can be

selected to download to the series of handsets.

The series of handsets initially receives information from the Java Application Descriptor

(JAD) file. The JAD includes information about MIDlet-name, version, vendor, MIDlet-Jar-

URL, MIDlet-Jar-size, and MIDlet-Data-size. Two additional JAD attributes will be Mot-

Data-Space-Requirements and Mot-Program-Space-Requirements. These two attributes

will help the KVM determine whether there is enough memory to download and install the

selected MIDlet suite. If there is not enough memory, the series of handsets will display a

“Memory Full” dialog prior to beginning the download.

Error Checks

There are two distinct cases when a Memory Full error can occur during the download

process. Memory Full will be displayed when the series of handsets does not have

enough memory to completely download the MIDlet. If the Mot-Data-Space-Requirement

and Mot-Program-Space-Requirements attributes are added to the JAD of the MIDlet, a

Motorola series of handsets can determine if enough memory exists on the phone before

the MIDlet is downloaded. These attributes may or may not be provided in all MIDlets.

Two separate prompts will be displayed depending on the existence of these attributes.

If there is not enough memory to download the application, the user will be given a

message to delete existing applications in order to free additional memory.

Once the MIDlet is successfully downloaded, the installation process begins. During the

installation of the MIDlet, the phone may determine there is insufficient memory to

complete the installation. This error can occur whether the Mot-Data-Space-Requirements

and Mot-Program-Space-Requirements JAD attributes are present or not.

In some instances, an application being downloaded may already appear on the series of

handsets. If this case exists, the series of handsets compares the version number of the

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Motorola J2ME Specifications Page 18