Please welcome Eric Giguere, author of the new book "Java 2 Micro Edition"

[paul wheaton]

Eric Giguere's new book "Java 2 Micro Edition" will be hitting the shelves on November 20th. In the mean time, he has graciously offered to do a bit of hanging out here to answer questions and participate in discussion.
My first question is: What's the diff between J2ME and J2SE? I'm guessing that there are a LOT less classes. Is the VM any different?

[Matt Midcap]

Welcome Eric! Thank you for your time in advance!
Matt Midcap

[Eric Giguere]

What J2ME does is provide a controlled process by which subsets of Java can be developed for smaller devices. At the most basic level, J2ME defines configurations, which defines minimum memory and capability requirements expected of a device along with what kind of features the Java VM has to offer and a minimal set of Java core classes. Right now there are two configurations:
-- The Connected Device Configuration (CDC) is for heftier devices and it uses the "classic" Java VM with all the same capabilities. It also includes a fairly large subset of the core Java APIs.
-- The Connected Limited Device Configuration (CLDC) is for smaller devices. It uses a new VM called the KVM that does not support certain features (floating point being the biggie) and has a much smaller subset of core Java APIs.
Usually, though, when people talk about J2ME they're referring to the CLDC/KVM.
Eric

[Andrew Brasek]

Eric,
Your book looks like it will be very usefull. I'm looking forward to its release.

[paul wheaton]

Does your book cover stuff like Java Ring and Java Card?

[Eric Giguere]

No, JavaCard is not discussed (well, one brief paragraph about it). The book is completely J2ME focused, mostly about the CLDC and MIDP. It's not an API reference, but an introduction/overview. The table of contents is listed up on my website at http://www.ericgiguere.com/j2mebook so you can see what the topics are. I do have a brief look at Waba as well.
Eric

[Kavita Ghia]

Welcome Eric,
My question is :
How can J2SE overcome the problems of low bandwidth hurdles,provide end-to-end security,alleviates memory constraints and be scalable ?
Thaks in advance.

[Eric Giguere]

Do you mean J2ME? Your post says J2SE.
Eric

[Kavita Ghia]

Hello Eric,
I am here to correct myself.I actually meant J2ME that was a typographical error and I am sorry for that.I would repeat my question here and would be very glad to receive some insight from you.Thanks in advance.
The question:
How can Java 2 Micro Edition overcome the problems of low bandwidth hurdles,provide end-to-end security,alleviate memory constraints and be scalable ?

A folk at JavaRanch,
Kavita.

[Eric Giguere]

Bandwidth issues are really limitations of the device -- any programming environment on those devices face the same limitations. Remember that the wireless networks are getting faster and to some degree those limitations will disappear.
As for end-to-end security, the usual answer is SSL/TLS. Sun has a lab project called kSSL which is an SSL layer for the CLDC, maybe they'll expose it at some point.
Scalability -- not really an issue here. Scalability is really a server-side problem, which is not what J2ME is for.

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Eric Giguere
author of:
Java 2 Micro Edition : A Professional Developer's Guide
PalmTM Database Programming: The Complete Developer's Guide