Sunday, February 24, 2002 07:53 PM
Unfortunately, the idea of writing code once and running anywhere does not hold in either J2ME or PersonalJava. Instead the idea is to write once and run on any specific set of similar platforms or devices.
To get this type of cross functionality will significantly reduce the power of the PocketPC and the Palm, but if it must be done the following information may be useful:
1) VAME (j9 VM) does not have complete MIDP support for Palm MIDP. It is missing the lcdui classes, so all graphical support is native (JNI). Sun does have a complete version but no access to source code.
2) MIDP does not support any of the AWT classes, so no cross support for graphical interfaces.
3) MIDP has no RMI, Security, reflection, beans, math, sql or text.
4) You will need to use vectors to maintain cross compatibility. No Lists or other collections.
5) MIDP has no float types (no floats or doubles)
Basically, you are going to have to do a lot of coding of factories/adapters/wrappers to get a good cross compatibility. Otherwise, HelloWorld may be the best that you can do.