It will save time during the course if everyone sets up their laptop with some essential required software in advance. Since Scala runs on the JVM, and the JVM is platform independent, it doesn't really matter what OS is used - in particular, Linux, Windows and Mac should all be fine. The basic requirements are, in order:
- Download and install Java 8 (OpenJDK is fine) - requires root/administrator access
- Download (or clone) this course code repository
- Download, install and test
sbt - Install a Scala-aware editor or IDE
- Download (but don't install) Apache Spark
Further information is given below. For avoidance of doubt, I am not assuming that you will have done a system-wide installation of Scala or the Scala compiler, and I don't particularly recommend doing so. It is not necessary if you are using sbt.
This step requires root/administrator access to your laptop, so if you don't have this, you will need help from your system administrator
Versions of Scala prior to 2.12.x worked with Java 6 and Java 7, but the 2.12.x Scala releases require Java 8, as Java 8 introduced a number of features which make it a better target for Scala compilation. I will be using Scala 2.12.10 in the course, so Java 8 is required. A more recent version of Java (eg. Java 11) should also be fine.
If you are running a Linux (or similar) system, you may prefer to use the OpenJDK rather than Oracle's Java. This is fine. On Debian-based Linux systems (including Ubuntu), this should be as simple as:
sudo apt-get update
sudo apt-get -y install openjdk-8-jdkIt should be something similar on other Linux systems. For other OS's, you may want to search the Internet for the best way to install Java on your system. You should install the full Java development kit (JDK), and not just the runtime engine (JRE). If in doubt, try the Oracle Java JDK download page: http://www.oracle.com/technetwork/java/javase/downloads
To check whether you have Java installed correctly, type java -version into a terminal window. If you get a version number of the form 1.8.x you should be fine.
The course code repository is at: https://github.com/darrenjw/scala-course - on the front page there should be a "Clone or download" button. If you are familiar with git, you should clone the repo on your system (and pull the latest changes the day before the course starts). If you are not familiar with git, you should download and unpack a ZIP of the course repo. If you go for the ZIP option, you should do this roughly two weeks before the course starts, before installing and testing sbt (below), but then also download and unpack a fresh ZIP no more than 2 days before the course starts (in case of last-minute changes).
Git users should be able to clone the repo with a command like:
git clone git@github.com:darrenjw/scala-course.gitOthers should be able to download this ZIP file. Linux users can download from a terminal with a command like:
wget https://github.com/darrenjw/scala-course/archive/master.zipsbt is the Scala build tool. You should download, install and test this before the course starts. The testing part is particularly important, as it will download and cache a lot of Scala libraries on your system ready for use during the course. See my sbt installation page for further details.
People starting out with programming in Scala are likely to benefit from writing code using an editor which can provide instant feedback and assistance. There are many possible options here, but it is not possible to provide support for every Scala-aware editor in existence. The course presenter uses Emacs together with Ensime, and considers this to be a good option for people already comfortable with the Emacs text editor. However, this is probably not a good option for people unfamiliar with Emacs. For everyone else, IntelliJ is probably a safer bet, and the course presenter has some familiarity with it, so should be able to provide basic support. The course presenter(s) will not be able to provide support for any other editor or IDE. It is therefore strongly recommended that participants comfortable with Emacs set up Emacs with Ensime, and that everyone else installs IntelliJ. Switching to another editor/IDE in the future will be quite straightforward, but it will save a lot of time during the course if everyone uses one of the two recommended IDEs. See one of the following pages for further details:
- Installing IntelliJ
- Installing Ensime (for Emacs users only)
- Installing the ScalaIDE (obsolete)
In case of a poor Internet connection during the course, it will be helpful if everyone could download this Apache Spark 2.4.5 package to their system in advance. Linux users can download from a terminal with a command like:
wget https://downloads.apache.org/spark/spark-2.4.5/spark-2.4.5-bin-hadoop2.7.tgzYou should make sure that you have a tool on your system which can unpack a "tgz" file (no issue for Linux users), but there is no need to "install" Spark - we will walk through installation/setup as part of the course.
Daniel Spiewak has a nice guide to getting started in Scala that could be a useful source of additional information. However, I will not be assuming that you have followed all of the advice in his guide. In particular, although the Ammonite REPL is very nice, I understand that there are issues with it on Windows. We will therefore not be using it in this course.