JAVA 認證心得 -- SCMAD (1)

JTWI (JSR 185)

##CONTINUE##

• In JTWI

• The minimum application thread count is 10
• text/vnd.sun.j2me.app-descriptor is the MIME type for JAD file.
• Java Technology for Wireless Industry (JTWI) is a meta-specification. So JTWI does not define any API.
• MIDIControl must be supported by a JTWI 1.0 compliant device to support MIDI playback. Note that this control need not be supported by a device that is only MIDP 2.0 compliant.
• A JTWI 1.0 compliant device that supports MMAPI 1.1 specification must implement VolumeControl interface for the Player instances.
• A JTWI 1.0 compliant device the value returned by the Canvas.getWidth() and Canvas.getHeight() method must be at least 125 pixels.
• A JTWI 1.0 compliant device must implement a mechanism for selecting a phone number from the device phone book when the user is editing a TextBox or TextField and the constraint is TextField.PHONENUMBER.
• TextField constant: ANY, EMAILADDR, NUMERIC, PHONENUMBER, URL, DECIMAL
• To identify a JTWI-complicant device and the implemented version of this specification the value of the system property microedition.jtwi.version must be “1.0”
• A JTWI 1.0 compliant implementation must allow a MIDlet suite to create a minimum of 5 simultaneously running Timers.
• The minimum volatile memory requirement for the Java Virtual Machine according to the JTWI 1.0 specifications is 256KB
• The MIDlet-Data-Size attribute refers to the RMS data size.MIDlet-Data-Size should be the minimum amount of space for RMS that the application can work with. According to the JTWI 1.0 specification, this should be 30KB.
• The implementation of SocketConnection using TCP sockets will throw java.securityException when an untrustedMIDlet suite attempts to connect to ports 80 and 8080, and 443
• The JTWI specification requirements only for the untrusted domain for GSM compliant devices.