As Simon says, it depends!
If you want to go ahead and explore Scala, you will need to put some work into it, as the learning curve can be a bit steep and it depends on your previous experience. You don't need to be a Java expert before you start with Scala, but some Java experience is helpful - and it may help you to appreciate some of the benefits of Scala. Learning Scala may even help to make you a better Java programmer! Scala is a hybrid OO/functional programming language, which means you can program in OO style and use it as a "better Java". Or you can program in a purely functional style like the real gurus. But most people seem to work somewhere in between those extremes, and it is common to start out programming Scala like Java and gradually become more functional as you gain experience/understanding. The Scala website has a
quick intro to Scala for Java programmers.
Personally, I found I needed some structured guidance when starting with Scala - I probably still do! I started with the excellent free Coursera course
Functional Programming Principles In Scala by Scala creator Martin Odersky. This course seems to run every year in the autumn and is a great way to get started with FP in Scala. We also have some tips for
getting started with functional programming here on JavaRanch. There is also some excellent material for learning Scala on
Twitter's Scala School website - Twitter has been a big user of Scala and has contributed various tools and libraries to the community.
There are not too many beginner's books for Scala, although I've heard good things about Bruce Eckel's
Atomic Scala which is aimed at complete beginners - you can download a free sample of the first 100 pages from the book's website.
Cay Horstman's book
Scala For The Impatient is aimed at people with some Java experience and gets good reviews, although it's a couple of years old now and Scala is moving fast.
The standard reference for Scala is probably Martin Odersky's
Programming In Scala (2nd edition), although this is also quite old now - I think the 3rd edition is due out soon.
My current favourite general purpose Scala book is
Programming Scala by Dean Wampler and Alex Payne (2nd edition came out in 2015), which covers a lot of ground in reasonable detail, from basic syntax through to reflection and macros. The ideal companion to this book is probably Alvin Alexander's
Scala Cookbook which is full of great recipes for doing all kinds of things in Scala.
As for your project, there are several options for a web application: the
Play framework is an MVC-style web application framework that is widely used in Scala-land,
Spray is a lightweight HTTP REST framework,
Scalatra is a lightweight web application framework that is also quite popular as an alternative to Play, and
Lift is another web framework although it doesn't seem to be as actively used or maintained as Play.
One useful starting point for installing Scala tools is the
Typesafe Reactive Platform, which bundles several Scala tools and frameworks (e.g. Play, Akka) together with the Typesafe Activator (a wrapper for the
SBT build tool - think
Maven without XML). The browser-based "Activator UI" tool is a Play application, and it allows you to download and run various tutorials and demo applications, which can be useful for getting a quick insight into new libraries etc, although the user-contributed projects vary in quality.
It's certainly true that Java is still far more widely used than Scala, and it probably always will be. But Scala is being used for lots of really interesting stuff, especially around Big Data, distributed processing and scalability. Tools like
Kafka (messaging),
Spark (distributed analytics) and
Akka (actor-based concurrency) are all written in Scala. There are Java APIs for all of these, of course, but it can feel more natural to use Scala for this kind of work e.g. the Scala API for Spark is much easier to use than the Java API, and there is a sense of "mechanical sympathy" when you work in this way.
A lot of this stuff is increasingly based on ideas from the
Reactive Manifesto, and Typesafe (the company behind Scala) has taken this up in a big way, so we can probably expect to see more developments in Scala along these lines. Back in 2013, Dean Wampler described big data as the
killer app for functional programming and so far I think he's been proven right.
For example, I'm seeing a growing number of Scala developer jobs in the financial sector, often in combination with Spark or Hadoop, and these jobs are very well-paid compared to equivalent Java jobs, although of course there are lots more Java jobs.
Anyway, there are lots of arguments for/against using Scala or Java, so you can surf around and look at these yourself. There have been some discussions about this here on JavaRanch too:
Why Scala? (2014)Why should one shift from Java to Scala? (2013)What kind of things are easier in Scala? (2013)Scala in commercial IT? (2013)Scala sceptic (2013)
Or you could just try it out and decide for yourself. Have fun!
1
) If the latter, then use Scala and have fun.
