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Please Explain the Diff. between all Sun PDA JREs

 
Robert Paris
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OK, I know that "technically" the java.sun.com website has an explanation of the differences between say Personal Edition Java and Micro-Edition. However, I still don't get it.
Can someone tell me:
1. Why all the different versions? (And what are the differences)
2. Which are still being supported?
2. How do I know when to use one over the other?
Thanks!
 
Michael Kroll
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Originally posted by Robert Paris:
OK, I know that "technically" the java.sun.com website has an explanation of the differences between say Personal Edition Java and Micro-Edition. However, I still don't get it.
Can someone tell me:
1. Why all the different versions? (And what are the differences)
2. Which are still being supported?
2. How do I know when to use one over the other?
Thanks!

Hi Robert,
as I know Personal Java was specified log before J2ME. J2ME consists of two configurations, the CDC (Connected Device Configuration) and the CLDC (Connected Limited Device Configuration). The latter one has two profiles, MIDP (Mobile Information Device Profile) and PDAP (PDA Profile). As you look at the SUN website for CDC there are some mor profiles (RMI, Foundation, Personal Basis Profile, Personal Profile). The CDC and Personal Profile seems to be the successor of PJava whereas PDAP is somewhat below CDC+PP, since PDAP supports most of the PP, but is based on CLDC not on CDC so the java.lang classes are not the same for instance.
The main difference between CDC and CLDC and their proper profiles is the hardware specs. CLDC is specified for devices such as cell phones and low power pdas whereas CDC is specified for high end PDAs and SetTop boxes, Terminals etc.
Still confused?
 
Robert Paris
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Wow, so let's see if I have this right:
If I want to develop for a Pocket PC (like Compaq iPaq) or a Palm Pilot or Handspring, I'd use CDC. If I wanted to program for a cell phone, I use CLDC. I never use pJava anymore (right?).
OK, so next question:
Other than the java website, is there a quick tutorial on how to INSTALL the JVM/JRE for CDC onto my PDA? Is it easy?
 
a sanjuan
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hi:
for another take on understanding CDC/CLDC and the profiles, try:
http://www.blueboard.com/j2me/intro.htm
for an intro on how to use PersonalJava on an iPAQ, try:
http://www.blueboard.com/j2me/notes/2002_7_26.htm
You can use MIDP/CLDC on a Palm device, but in future, hopefully, we'll use the new PDA profile (PDAP) for Palm devices (although MIDP apps will still run fine).
I think sun pretty much decided to ignore PocketPC and leave it to third party companies to service this market.

Originally posted by Robert Paris:
Wow, so let's see if I have this right:
If I want to develop for a Pocket PC (like Compaq iPaq) or a Palm Pilot or Handspring, I'd use CDC. If I wanted to program for a cell phone, I use CLDC. I never use pJava anymore (right?).
OK, so next question:
Other than the java website, is there a quick tutorial on how to INSTALL the JVM/JRE for CDC onto my PDA? Is it easy?
 
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