Hai friends, I have a big doubt now,
Has Android really replaced J2ME and WML?
If Android has replaced them then please tell what is the reason for that?
How has Android replaced the other two mentioned above and what is the reason that J2ME and WML cannot withstand against Android in market?
J2ME is a java platform for embedded devices. Android is a mobile operating system. So you can't make a direct comparison.
However, if you look at the Java based Android SDK vs J2ME: The share the same basis with the core Java libraries. They provide different UI layers and application paradigms.
Android is more powerful, and thus used in higher end phones. However J2ME is still used in a lot of older/less powerful devices. The Androd SDK provides a lot of things that are not part of J2ME. You might want to read through the dev guide to get an idea of what Android is capable of.
I would argue that Android hasn't completely replaced the two others, they obviously still exist and there are other platforms that still use J2ME. But, even so, I think it has practically replaced the other two just by virtue of its popularity.
The market share for so-called smart phones is growing rapidly, the market share for Android phones is growing rapidly. I don't see the market share of any devices based on J2ME growing rapidly. As for WML, I don't see it growing either because most smart phones now feature a browser that is far more capable than mobile browsers of the past. The one I have in my iPod Touch is very good, the one on my Android phone is adequate for most sites. I don't have to have special sites built just for my phone any more. It's nice if they are there, but they definitely don't need to be constructed using a different markup language, a simple alternate CSS style sheet would probably do just as good a job.
There are some considerations that are helpful that sites can take into account with regard to width and use of Flash, etc. but I would argue that the need for WML has gone away for the most part before it ever became really popular.
Android phones are getting cheaper, soon you could get an android phone for almost the price of the mid-range J2ME handsets
Android SDK doesnt face the issue of the first mover that J2ME had, so the SDK is quite powerful and in tune with the times, where as J2ME wasn't updated for years
Android, though fragmented in terms of versions, doesnt have the JSR nightmares that J2ME has (Vendors not implementing the JSR completely or in a different fashion)
However, things could really be great for J2ME, if Oracle succeeds in making the J2ME.next, We could really get an almost write once run anywhere, if they can somehow also allow installable VM's like standard J2SE VM