Myths about JavaFX, Android, and J2ME | Hacker News Reader

Myths about JavaFX, Android, and J2ME

bitsandbuzz.com

16 pointsbbuffone9 comments

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Android kept the Java language, and pitched out the JVM.

Does this seem backwards to anyone else?

It does. What would be the rationale for this? Is it just that they didn't want the standard Java ME runtime?

Here is some speculation on why: http://www.betaversion.org/~stefano/linotype/news/110/

Very interesting article on a possible explanation. Google is also doing this with GWT.

It looks like this is good news for anything that targets the JVM though, as it looks like the path to Dalvik bytecode is:

    .java -> [javac] -,-> .class -> [dx] -> .dex
                     /
    ??? ------------'

Has anyone done this, with Clojure, for example?

The most novel thing I've heard about Dalvik is their zygote technique for minimizing app startup time. The zygote is is a Dalvik process that's loaded and ready but for the actual bytecode it will need to run. To start a process it first makes a fork of the zygote, which allows for more shared memory and a more expensive initial setup time for the zygote without any penalty when creating new Dalvik processes.

I dunno if this technique necessitated writing their own VM however.

Dalvik is basically a JVM. A lot of Java bytecode (including non-Java languages) will run on Android.

Most of these high-profile phones do not have Java out of the box, and getting a Java runtime can even be challenging. For example, there is no JavaVM out of the box on iPhone, Android G2/HTC-Magic, and Treo 750 WinMobile (I could not find one on my old Treo 750 WinMobile). And for the rest—well, the J2ME market is very fragmented.

Loopt seems to get it done in J2ME quite well. I don't buy it.

As a US mobile users, I can't get Java on any of my phones (G2 or Treo), and I am a geek. There might be some JVM, but I did not find them.

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