J#

fuze writes: "It's basically a way for Java developers to migrate their Java apps to .NET.... even provide a 'convenient' migration tool... check it out on MSDN." News.com has a story describing Microsoft's plans to suck Java into .Net, and some commentary saying basically, "No one will use it".

Comments

Initial reactions

[Rogerborg]

Microsoft are still strongly implying (at least) that Visual J++ is Java. Uh, wait, didn't a court tell you to stop doing that?

• "Visual J# .NET enables Microsoft Visual J++ customers and other Java-language programmers"

Tsk, tsk, Bill. There's no "other" in that sentence.

The focus seems to be on J++ developers, not Java developers. But personally, I will use J# iff:

• It compiles Java completely and correctly.
• It compiles to a native .NET executable that gives a significant speed advantage over VM bytecode on a .NET platform.
• I have to make exactly zero changes to my Java to have it compile to both VM bytecodes and to a .NET executable.

Basically, I can live with loading J# and hitting compile once for each of my Java projects. If it's any more hassle than that, I agree, it's not worth my while.

However, I'm keeping an open mind. Microsoft's decision to not include a JVM in WinXP concerns me, as does the increasing size of the Sun VM. I love Java and want to keep using it purely, but I'm not going to cut off my nose to spite my face. If Microsoft and Sun collude to make it hard to use Java and easy to use J#, I could be swayed. I hope not though.

Re:.NET

[jonnosan]

This is the perspective of someone with a couple of years experience in "enterprise" development, i.e. apps that have a UI that is probably a bunch of data entry forms, a database at the back, and a "business logic" layer that looks at the input, massages it, acts on it, sends it to the db, etc.

These sorts of apps are not very sexy compared to writting an OS or a game or something, but they're what 90% of developers in the world work on.

A typical enterprise app will need to have a bunch of different front ends (e.g. web interface, a simple gui for data entry clerks, a bunch of reports) etc. Also, you'll have lots of people working on different bits and peices, and lots of changes going on all the time, e.g.say a sales manager comes up with a new promotional scheme that gives volume discounts you need to update your app to handle the calculations.

So with all these people working on apps that are evolving rapidly, you can end up with spaghettii code pretty quickly. If you want to have something that's maintainable, you really need to use OO and come up with an object model that seperates the user interface, the business rules, and the data layer.

The problem with this is that it is hard to have an object model that works well over distributed systems, and hard to have an object model that can be used by developers using multiple languages.

COM is a start to allowing objects to be used from multiple objects, and over distributed systems, but it has limitations, largely related to the fact that different languages don't have the same idea of basic data types.

.NET solves this by making all languages share a virtual machine that defines a bunch of basic data types, and a base 'object'. This means that any object created in one .NET language can be accessed by another .NET language.

So you can have a your web front end people write ASP (VB) pages that interact with business logic written in c# without having to compromise your object model.

Open source non-Swing Java tree and table Java

[jonabbey]

Actually, if you are looking for less complicated tree and table components, check out the ones included with Ganymede.

I wrote them because I needed them for Ganymede development, and Swing hadn't quite come along yet. I kept them because they are simple to use, they are pretty high performance, and you can do fancy tricks like node dragging ihttp://www.arlut.utexas.edu/gash2/doc/javadoc/arl ut/csd/JTable/baseTable.htmln the tree with little-to-no effort.

You can read the Javadocs on them here and here.

They are licensed under GPL, along with the rest of Ganymede.