ubuntu change default java path

C++
#Update repo
sudo apt update

# Install java 8 from ubuntu repo
sudo apt install openjdk-8-jdk -y

#Set JAVA_HOME Path
ls /usr/lib/jvm/java-8-openjdk-amd64/
 export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
 echo $JAVA_HOME
 
 #Add JAVA bin directory to the PATH variable
 export PATH=$PATH:$JAVA_HOME/bin
 echo $PATH
 java -versionsudo update-alternatives --config java
Source

Also in C++: