Code

JDK install

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer
sudo apt-get install oracle-java8-set-defaul

Maven install

Unix-based Operating System (Linux, Solaris and Mac OS X) Tips
Check environment variable value
echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home
Adding to PATH
export PATH=/opt/apache-maven-3.5.3/bin:$PATH

Eclipse