How to install openjdk-8-jdk on Debian 10 (Buster)?

Question

It seems Debian does not support openjdk-8-jdk anymore due to a security issue. What is the easiest way to install openjdk-8-jdk for Debian 10 (Buster)?

Answer 1

I was migrating from Jessie to Buster, and found that not-so-old, legacy code would not compile and run on JDK11.

I managed to copy all java8 folders from my Jessie distribution, reworked the links, and set that as a new JDK on Eclipse. That works so far.