consult the JTWI specification available from the Java Community Process
(JCP) website ( http://jcp.org ).
CLDC 1.0/1.1 must allow a MIDlet suite to create a minimum of 10
running threads and must support Unicode characters.
MIDP 2.0 must allow creation of at least five independent record
stores, must support the JPEG image format and must provide a
mechanism for selecting a phone number from the device's phone-
book when the user is editing a TextField or TextBox with the
GSM/UMTS phones must support SMS protocol push handling within
the Push Registry.
MMAmust support MIDI playback (with volume control), JPEG encod-
ing for video snapshots and the Tone Sequence file format.
The JTWI specification also clarifies aspects of the MIDP recommended
security policy for GSM/UMTS devices relating to untrusted domains.
2.8.3 Symbian and the JTWI
Symbian supports and endorses the efforts of the JTWI and is a member
of the JSR-185 expert group. Releases of Symbian OS from version 9.1
provide implementations of the mandatory JSRs (Wireless Messaging API
and Mobile Media API) and configurations (CLDC 1.0/1.1 and MIDP 2.0)
specified by the JTWI. They also provide many other JSR implementations,
about which you can find information on Symbian's website.
In 2003, JTWI was still in its draft phase, therefore only a couple of
Symbian OS phones supported it, and only partially. At the time of writing
(2008), the vast majority of Symbian devices supports the full range of
JTWI specification plus many optional APIs. Developers can therefore rely
on JSR-185 support on Symbian devices for their JTWI-based applications.
2.9 Mobile Media API
The Media API is fairly limited, giving support only to basic audio
types. Smartphones these days have many more multimedia capabilities.
Therefore it is necessary to expose all this multimedia functionality, such
as tone generation, photo capture, and video playback and capture, to Java
ME applications, so developers can create truly compelling multimedia
applications attractive to end users.
This was achieved through the creation of JSR-135 - Mobile Media
API (MMAPI). MMAPI is indicated for a JTWI-compliant device. Note that