First I must admit that I don't buy GWT's approach. There is a reason why we don't write HTML code from servlets anymore. Programmers usually are bad UI designers (look at my website for something to back my claim ;-) and great UI designers usually don't want to write Java code. With the GWT model you write your UI in Java and automatically translate it to HTML. This means layout changes require the Java coder to perform it, which is bad. Maybe you can get around most problems with the help of CSS, but I doubt that.

Anyway, I downloaded the toolkit and played with it last night, and found it to be a bit cumbersome to work with. Scripts that generate scripts and no integration with Ant to speak of.

I stopped after my first few steps and started to put together a little Ant library that makes using GWT a bit less cumbersome - at least to me. This is very rough alpha level code, but it works for me. I'm not sure I'll take this any further, but if anybody is interested in it, feel free to use the code - the license is pretty permissive. Source and binaries are available here.

There is no documentation right now. A quick rundown:

Reading this a second time, it is a bit confusing, I guess.

You must provide a class name to Google's applicationCreator script, let's say you've chosen de.samaflost.client.Dummy (the .client. piece is recommended by Google), then gwt:compile's classBase would be de.samaflost.Dummy and 's startPage would be de.samaflost.Dummy/Dummy.html.

Putting the stuff together. To seed a new GWT application you'd use

  <target name="applicationCreate">
    <mkdir dir="project"/>
    <gwt:applicationCreator dir="project"

This will generate the initial directory structure in the project subdirectory and will also generate an Ant build file that contains (among other things)

  <target name="gwt-compile" depends="compile">
    <gwt:compile outDir="www" gwtHome="C:\OSS\gwt-windows-1.0.20"

  <target name="gwt-shell" depends="compile">
    <gwt:shell outDir="www" gwtHome="C:\OSS\gwt-windows-1.0.20"

This means you don't need to worry about classBase or startPage at all. It also means you now have the Java -> JavaScript step as part of your Ant build process and available to your continuous integration runs.

I haven't found the time for an actual RPC example yet, but expect it will lead me to a special gwt:war task that knows what to package where.

Finally, it may be worth noting that three of the four tasks are implemented in Ant, not Java (i.e. they are <macrodef>'s hidden in the antlib descriptor.

path: /en/Java/GWT | #