How to deal with the most common classes missing on J2ME

Question

I\'m trying to code an application which runs un different java platforms like J2SE, J2ME, Android, etc. I already know that I\'ll have to rewrite most of the UI for each pl

Answer 1

J2ME is brutal, and you're just going to have to resign yourself to doing without some of the niceties of other platforms. Get used to Hashtable and Vector, and writing your own wrappers on top of those. Also, don't make the mistake of assuming that J2ME is standard either, as each manufacturer's JVM can do things in profoundly different ways. I wouldn't worry much about performance initially, as just getting correctness on J2ME is enough of a challenge. It is possible to write an app that runs across J2ME, J2SE and Android, as I've done it, but it takes a lot of work. One suggestion that I'd have is that you write the core of your application logic and keep it strictly to java.lang, java.util and java.io. Anywhere where you're going to be doing something that might interact with the platform, such as the file system or network, you can create an interface that your core application code interacts with, that you have different implementations for the different environments. For example, you can have an interface that wraps up HTTP stuff, and uses javax.microedition.io.HttpConnection with J2ME and java.net.HttpURLConnection on Android. It's a pain, but if you want to maintain an app running on all three of those environments, it can get you there. Good luck.