J2ME Learning Notes (i)

Notes first I like to declare that I am a layman to J2ME, and because the work does not have anything to do with it, so there will certainly be a lot of good masters to





look very retarded things, oh, I hope we do not BS on the good. At the same time hope that the master also to guide the younger brother. Oh.





personal interest to see what j2me. In fact, it is mainly to help a brother to complete his graduation design. Oh, don't know he
every day




is busy doing something in us anyway, only knowing that when I ask him he will tell me that he is going to work. Forget it, he doesn't care. Just wait till he gets back.





.





has been looking at this aspect of things for 3 days, the first day is to look at some of the basic concepts of J2ME. Alas, these things have never been touched





, there is no way, no basic concepts no way. The next day helped him write a database operation program that runs on a PDA. Of course, 10
.




points of simple, hehe. The third day, the thing mutation, request more and more, good, anyway own interest also come up, hehe, so continue to grind





to investigate.


today I put the key things in some of the basic concepts I saw on the first day. Take the time to write that
for the kid tomorrow.




a PDA on the program put it up. Later slowly put their own learning process, learning some ideas and difficulties to take out, and everyone together





share.


Oh, first of all, certainly is also the most important and the simplest concept slightly, J2ME is what dongdong? Not very good description, hehe, with a





an expression to express, J2ee>j2se>j2me>smart card This is also sun company to give this Java technology positioning. Of course, the




The foundation of all
is based on J2SE. (But the choice is different, some of the basic types of support, the basic objects will also be different oh.) ) hehe





, this is the simplest.


Below said I look at the material time let me just start very depressed several nouns, hehe, mainly still because has not seen before,





for the first time it was a little strenuous. Take it out, that man if want to learn J2ME, and is just beginning to learn or will have some effect ^_^





1, cldc:connected Limited Device configuration--are used in limited power such as mobile phones, PDAs.





2, cdc:connected Device configuration--application in the power supply adequate equipment, hehe, like the top of the machine




The
box is the ^_^
within this range.




3, for different class library support, the class libraries supported by J2ME CLDC are included in the J2ME CDC's class library. Relative to J2SE,





they support a reduced and expanded class library. And precisely because of the difference between CLDC and CDC, Java introduces the concept of configuration





。 Oh, I think you can take configuration as J2ME for the two types of embedded device specifications. J2ME for the most important difference with J2SE except





There is a lack of basic class library support and the introduction of the Java.microedition.io class library.





4, Profile:profile is the structure of the configuration above the specification, its existence should be to make a clearer distinction between the





Embedded systems on how Java should be developed and what they should be capable of. How to display the interface of all kinds of embedded systems is fixed





righteousness in profile.