Update JDK installation instructions

week1/00-tools-setup.md

@@ -23,11 +23,26 @@ sudo dnf install java-1.8.0-openjdk-devel
 
 ### On macOS
 
-macOS either comes with a pre-installed JDK, or installs it automatically. To verify your JDK installation, open the Terminal and type `java -version`. If the JDK is not yet installed, the system will ask you if you would like to download and install it. Make sure you install Java 1.8.
+First, install Homebrew:
+```shell
+/usr/bin/ruby -e "$(curl -kfsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
+```
+
+Install OpenJDK 8:
+```shell
+brew tap AdoptOpenJDK/openjdk
+brew cask install adoptopenjdk8
+```
+
+Set it as the default Java version:
+```shell
+echo "export JAVA_HOME=$(/usr/libexec/java_home -v 1.8) >> ~/.bash_profile
+echo "export PATH="$JAVA_HOME/bin:$PATH" >> ~/.bash_profile
+```
 
 ### On Windows
 
-[Download and run the JDK 8 installer for Windows from Oracle's website.](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html)
+[Download and run the OpenJDK 8 installer.](https://adoptopenjdk.net)
 
 ## Step 3: Verify your JDK installation
 
@@ -49,8 +64,6 @@ See [https://www.scala-sbt.org/1.x/docs/Installing-sbt-on-Linux.html](https://ww
 
 ### On macOS
 
-First, install Homebrew from [https://brew.sh](https://brew.sh) Then run:
-
 ```terminal
 brew install sbt@1
 ```