Currently, the official Docker image for Java comes from the OpenJDK project: https://hub.docker.com/_/openjdk/. We will use an alternative Docker image from the AdoptOpenJDK project. It contains the same binaries from the OpenJDK project, but provides variants of the Docker images that meet our needs better than the Docker images from the OpenJDK project.

In this section, we will use a Docker image that contains the full JDK (Java Development Kit) with all its tools. When we start to package our microservices in Docker images in the Using Docker with one microservice section, we will use a more compact Docker image that is based on the JRE (Java Runtime Environment) only containing the Java tools required at runtime.