Oracle Java 8 Installation which sets the licence agreement in advance. This way this procedure can be included in any automated installation. I did use this in a packer build.

Oracle Java 8 Installation for automation

sudo apt-get update

# make add-apt-repository available
sudo apt-get install -y software-properties-common python-software-properties

## add java 8 repo
sudo add-apt-repository -y ppa:webupd8team/java
sudo apt-get update

# setting to automatically accept the licence to prevent the prompt
sudo echo debconf shared/accepted-oracle-license-v1-1 select true | \
sudo debconf-set-selections
sudo echo debconf shared/accepted-oracle-license-v1-1 seen true | \
sudo debconf-set-selections

# install java 8 and set defaults
sudo apt-get install -y oracle-java8-installer
sudo apt-get install -y oracle-java8-set-default