Download tar.gz file from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html Then:

mkdir /opt/java-jdk
tar -C /opt/java-jdk -zxf jdk-8u131-linux-x64.tar.gz
update-alternatives --install /usr/bin/java java /opt/java-jdk/jdk1.8.0_131/bin/java 1
update-alternatives --install /usr/bin/javac javac /opt/java-jdk/jdk1.8.0_131/bin/javac 1

• Debian 9 (Stretch)
• Java 8

• https://linuxconfig.org/how-to-install-oracle-java-se-development-kit-on-debian-9-stretch-lin
• http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html