02 Spark world — How to Install Scala
- Scala is a general-purpose programming language.
- It supports object oriented, functional and imperative programming approaches.
- It is a strong static type language. In scala, everything is an object whether it is a function or a number. It does not have concept of primitive data.
Installation process on CentOS7:
Step 1: Update your system
After logging in as the non-root sudo user from your SSH terminal, the first thing you need to do is to update the system:
sudo yum update -y && sudo reboot
Use the same user to log in again after the system reboots.
Step 2: Install OpenJDK Environment
Scala requires the Java runtime version 1.6 or later. Here, you can install the latest version of OpenJDK Runtime Environment 1.8.0 using YUM:
sudo yum install java-1.8.0-openjdk.x86_64
You can validate the installation of Java runtime by running the following command:
This command should output something that resembles:
openjdk version "1.8.0_91"
OpenJDK Runtime Environment (build 1.8.0_91-b14)
OpenJDK 64-Bit Server VM (build 25.91-b14, mixed mode)
Besides, you need to set the “JAVA_HOME” and “JRE_HOME” environment variables.
sudo cp /etc/profile /etc/profile_backup #Backup the profile file in order to prevent unintentional mistakes
echo 'export JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk' | sudo tee -a /etc/profile
echo 'export JRE_HOME=/usr/lib/jvm/jre' | sudo tee -a /etc/profile
Now, you can print the two environment variables for review:
Step 3: Download and install Scala
Download and install the latest Scala RPM file from the Scala official website, which at the time of writing is 2.11.8:
sudo yum install scala-2.11.8.rpm
Verify your installation:
The output should resemble:
Scala code runner version 2.11.8 -- Copyright 2002-2016, LAMP/EPFL