Just An Application

July 24, 2009

What’s New In MIDP 3.0 ? Part 42: MIDlet Suite Attribute Miscellany

Filed under: Java, JME, MIDletSuite, MIDletSuite Attributes, MIDP, MIDP3 — Tags: , , , — Simon Lewis @ 11:52 am

1. MIDlet-Minimum-Canvas-Size And MIDlet-Maximum-Canvas-Size

The minimum size, in pixels, of a full-screen Canvas that the MIDlet(s) in a MIDlet Suite are intended to support can be specified at installation time using the



The maximum size, in pixels, of a full-screen Canvas that the MIDlet(s) in a MIDlet Suite are intended to support can be specified at installation time using the



Installation of the MIDlet Suite will fail if the specified constraints are not met by the primary Display of the device.

If both attributes are specified then it is an error if the minimum size is not less than or equal to the maximum size and installation of the MIDlet Suite will fail.


  • The documentation for these attributes does not specify their format, nor can I find a definition of it anywhere else in the documentation.
    However, the early draft review did contain an example of a JAD containing the following

    MIDlet-Minimum-Canvas-Size: 120, 120

    so possibly that is the intended format ?

2. MIDlet-Required-IP-Version

The IP version required by a MIDlet Suite can be specified by using the



The value of the attribute must be one of

  • ipv4
  • ipv6
  • any

If the required version is not supported by the device then installation of the MIDlet Suite will fail.

3. MIDlet-Profile-Request



attribute is used to specify that the MIDlet Suite JAD download request must be accompanied by the UAProf headers necessary to detemine the capabilities of the device.

The specification requires that this is done for all JAD downloads, however, it is possible that the JAD was downloaded in some another manner and then passed to the MIDP 3.0 implementation. In these circumstances if the MIDlet-Profile-Request attribute is present and has the value true then the JAD download must be repeated with the download request being accompanied by the necessary UAProf headers.

4. MIDlet-Upate-URL



can be used to specify an RFC 3986 conformant absolute URL to be used for automatic updates of the MIDlet Suite


  • It is not clear from the specification what the automatic update of a MIDlet Suite actually involves.

    The attribute documentation says

    If the value contains a valid URL, the automatic update of the MIDlet suite MUST be requested from this URL. Note that this overrides the priority rules used to decide which URL is used in updating. In this case other URLs MUST NOT be used, and other rules related to the update MUST remain in effect.

    If the URL is empty, user MUST NOT be able to activate the automatic update feature of the AMS.

    Searching the Provisioning section of the specification turns up this

    If the provisioned MIDlet suite has the MIDlet-Update-URL attribute in the JAD file or the JAR manifest, the implementation MUST use it to configure the automatic update feature. The value of this attribute MUST either be empty or contain a valid URL. For details, see the description of the MIDlet-Update-URL attribute in Application Attributes.

    which simply refers to the attribute documentation quoted above, and that is the only occurence of the word automatic anywhere in the Provisioning section.

Copyright (c) 2009 By Simon Lewis. All Rights Reserved


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