J2ME Section Index | Page 2
How does an Xlet tell the application manager it wants to end?
Call the notifyDestroyed() method of the XletContext.
What certifications are available for mobile Java developers?
Sun offers a Sun Certified Mobile Application Developer (SMAD) certification for J2ME developers. For more information, see http://www.sun.com/training/certification/java/java_j2me.html.more
What is the mime type for JAD files?
text/vnd.sun.j2me.app-descriptor
What is the mime type for JAR files?
application/java-archive
What system properties are available under J2ME?
Sun maintains a list at http://developers.sun.com/techtopics/mobility/midp/questions/properties/. The exact set depends upon the optional packages installed.more
Do the MIDP APIs support server sockets or HTTP connections?
The MIDP 1.0 specification requires all compliant implementations to support the client portion of the HTTP 1.1 protocol. MIDP 1.0 does not require that any other particular protocol(s) be implem...more
What is "1G" wireless technology? How does it relate to J2ME?
Cellular phone technologies have evolved in several
major phases, denoted by "Generations", or "G" for
short.
"1G" is short for first generation analog cellular technology (AMPS is
one example o...more
What is "2.5G" wireless technology? How does it relate to J2ME?
Cellular phone technologies have evolved in several
major phases, denoted by "Generations", or "G" for
short.
"2.5G" is an acronym which represents various
technology upgrades for existing secon...more
What is "2G" wireless technology? How does it relate to J2ME?
Cellular phone technologies have evolved in several
major phases, denoted by "Generations", or "G" for
short.
"2G" stands for second generation cellular technology.
2G systems use circuit-based,...more
What is "3G" wireless technology? How does it relate to J2ME?
Cellular phone technologies have evolved in several
major phases, denoted by "Generations", or "G" for
short.
"3G" refers collectively to third generation
cellular technologies. These technolog...more
What is GPRS?
General Packet Radio Service (GPRS)
is a 2.5G cellular technology designed to be overlayed on top of existing infrastructure in 2G GSM cellular networks. Carriers will leverage all of their pre-e...more
Do the J2ME MIDP APIs support JDBC based database connectivity?
No, not directly.
You may however use HTTP to talk to a proxy (which might be a Java Servlet
or JSP, for instance), which in turn may use JDBC to interact
with the database. MIDP supports HTTP...more
What is SMS?
Short Message Service (SMS) allows GSM-based mobile phones to send and receive short text messages. These email-like messages are of very limited length, often 160 characters or less.
SMS is ...more
What is SyncML? How does it relate to J2ME?
SyncML (short for "Synchronization Markup Language") is an XML-based markup language used to exchange information in calendars, address books, and the like. SyncML will be used by many J2ME-power...more
Can a midlet talk to a Java Card applet?
No. Currently, the MID
profile doesn't provide any API that would let a midlet talk to a
Java Card applet run on the SIM card. It's really a shame, because since this would certainly lead to
ma...more
