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I am working on a web site that will help students practice their Scala programming skills. As I labored along, writing my JSF app code, I thought "this is silly-why not practice Scala at the same time?" But I like JSF and wasn't ready to jump to Lift or Vaadin. With Eclipse, this isn't all that hard. Install the Java plugin. Make a dynamic web project in the usual way, using the Java EE perspective. Then, switch to the Scala perspective, right-click on the project, and, if all planets are aligned correctly, you will get a menu item "Add Scala nature". (If they are not, see here for a manual approach.) Add your managed beans as Scala classes. Finally, switch back to the Java EE perspective, select the project properties, and add the Scala library JAR as a Java EE module dependency. But I like NetBeans and wasn't ready to switch to Eclipse. (Unfortunately, JSF 2 support in Eclipse is pretty minimal, the Glassfish integration is a bit flaky, and the Scala plugin has very little usable code completion.) NetBeans doesn't let me add a "Scala nature" to a web project. If I add Scala files to the project, I can edit them with the Scala editor, but they just get copied to the WAR file, without any compilation. I had one look at the Ant scripts for a Scala and a web project and decided that I wasn't going to figure out how to merge them. This blog shows how you can use Maven to make a mixed Scala/Java project in NetBeans. So I gathered up JSF and Scala pom.xml files from here and here, cut out the considerable crud from the JSF POM file that was probably meant for supporting Tomcat, and merged the results to the best of my ability-see below. You use the usual Maven directory structure, but with a src/main/scala directory instead of src/main/java:

There was a recent outburst in blogs on the topic of Groovy and how it compares to Java. Although I respect the youthfull entusiasim of Groovy and Co. working on this little exercise I'm just perplexed by the "WHY?" in this whole discussion. Let me just say again: W H Y ?!?! 1. Practically no one cares about Groovy (let alone Groovy++ strap-on) beyond Grails community. So this language just as "widely accepted" as Ruby (at least for enterprise software development) 2. If you know Java it's equally "challenging" to pick up either Groovy or Scala. Don't let anyone insult your intelligence by claiming that Scala syntax is somehow more complex than Groovy. In both languages you will need to adapt to functional thinking - and that's where you will have to spend a couple of weekends… 3. If you know Groovy - you already know 90% of Scala (different syntax and few extra features can be picked up in the evening) 4. Scala is designed by people who have proper academic background, experience and talent in the area of language design - Groovy has never been that way (and anyone who dares to look inside of Groovy runtime or history of changes in it will attest to that). NOTE: it did come out rather strong - but that's how I feel about it and after some thinking I'll leave as is. Nothing personal to anyone reading it… 5. Scala as a post-functional language is years ahead of Groovy (static typing with best-in-business type inference, highly tuned mix of imperative and functional styles, powerful and done-right generics, etc.) 6. Groovy will ALWAYS be slower than Scala or Java (latest benchmarks put even Groovy++ about 50 times slower than Java) just by its nature unless someone changes the language and rebuilds the runtime from the ground up. 7. Once we get decent integration with Eclipse, NetBeans and IDEA for Scala, the Groovy will lose its only serious advantage

"JSwat is a graphical Java debugger front-end, written to use the Java Platform Debugger Architecture and based on the NetBeans Platform. JSwat is open-source software and is freely available in both binary and source code form. Its features include sophisticated breakpoints; colorized source code display with code navigator; byte code viewer; movable display panels showing threads, call stack, visible variables, and loaded classes; command interface for more advanced features; and Java-like expression evaluation, including method invocation. "