hi, I am starting out writing j2me apps. I was just reading the sun website and found out there are two versions of toolkits available. my questions are: 1)will the applications written in toolkit 2.0 work in MIDP 1.0 devices? 2)will the applications writen in toolkit 1.04 work in MIDP 2.0 devices? 3)is there any MIDP 2.0 advices on the market right now? is it true that sooner or later MIDP 2.0 will replace 1.0? 4)can I write applications for my pocket pc with either toolkit? (from the sun website, it says it only works for simple PDAs(??)) sorry for my ignorance...Thanks a lot!! -serena
The toolkit only offers development libraries and device emulators. So: 1. Yes, but only if you restrict youself to MIDP v1.0 APIs. 2. Yes, since MIDP v1.0 is a subset of 2.0. Any 1.0 app will run on 2.0 device or emulator. 3. Yes, Nokia 6600 is a MIDP 2.0 cell phone. IBM and Jeode have MIDP v2.0 VMs for Palm and PocketPC PDAs. All major cell phone vendors and wireless carriers have committed to MIDP 2.0. 4. Yes, MIDP apps run on PocketPC. But you have to install a MIDP VM using ActiveSync. Check out the IBM WebSphere Micro Environment. It has a "free" MIDP VM for PPC.
Thanks for answering all my questions! I just have couple more questions: -For MIDP 1.0 devices, can I download something to the device to make them run something that's for 2.0? -in this sun website: http://java.sun.com/products/j2mewtoolkit/index.html it says "For developing applications for MIDP 1.0 devices, use the J2ME Wireless Toolkit version 1.0.4_01. For developing applications for MIDP 2.0 devices, use the J2ME Wireless Toolkit version 2.0. The 2.0 version also includes built-in support for the Wireless Messaging and Mobile Media APIs. " so..like what you said, if using toolkit 2.0 can write applications for MIDP 1.0.4 devices...I don't need to have two different toolkits to build applications for different MIDP. and the best to do is to download Toolkit 2.0 to build apps for both MIDP, am I correct? Thanks so much again =) -serena
Originally posted by Serena Chen: For MIDP 1.0 devices, can I download something to the device to make them run something that's for 2.0?
If you are talking about upgrading the runtime environment on the device, you are out of luck for most cell phone devices since those VMs are burned into the hardware. But for most PDAs, you can upgrade the VM. Yes, you only need to the J2MEWTK 2.0 to develop both MIDP 1 and 2 applications. However, if your target device is MIDP 1 and you accidentally used MIDP 2 APIs, the WTK will not alert you. You will only find out when you deploy to the device. So, you need to be familiar with the MIDP APIs.
hi Serena, this is a very interesting / important post, i think. what devices are you targetting and within how much time? if you are targetting mass-market phones in the near future, you should probably restrict yourself to MIDP1 (and use J2MEWTK 1.0.4) if you possibly can. remember that a later move from MIDP1/WTK1.0.4 -> MIDP2 _should be_ totally painless. if you really need the extra MIDP2 APIs that might change this. so, how important it is the extra MIDP2 functionality, and how important is device coverage and in what timeframe? cheers, dan.