Java Docker image

This image is based on Alpine Linux image, which is only a 5MB image, and contains Java runtime (JRE) and Java development kit (JDK) conveniently packaged into separate Docker tags.

DEPRECATION DUE TO ORACLE JAVA LICENSING CHANGE

Thank you to everyone using images derived from this repo, to everyone who inspired and contributed. After April 2019, due to Oracle Java licensing changes, this repo is deprecated, and is now for reference only. No new builds will be published to frolvlad/alpine-java repo on Docker Hub from this Github repo.

As announced, Java licensing changed, and starting April 2019 commercial usage of Oracle Java required subscription. In other words, switch to OpenJDK, or use older versions of Oracle Java (for reference, pre-built images are available on Docker Hub)

Official OpenJDK images receive regular updates, and are available at https://hub.docker.com/_/openjdk, including 8-jre-alpine (85MB), 8-jdk-alpine (105MB), 8-jre-slim (204MB), 8-jdk-slim (243MB), 8u212-jre-slim (204MB), 8u212-jdk-slim (243MB), etc..

For more details about Oracle Java Licensing, checkout this article: https://medium.com/@javachampions/java-is-still-free-2-0-0-6b9aa8d6d244

TL;DR

Oracle JDK 8 is going through the “End of Public Updates” process, which means the April 2019 update will restrict commercial use. However, since Java SE 9, Oracle is also providing Oracle OpenJDK builds which are free for commercial use (but only updated for 6 months). There are also free OpenJDK builds which will be updated (including security patches) from other providers like AdoptOpenJDK, Amazon, Azul, BellSoft, IBM, jClarity, Red Hat, the Linux distros et al.

And many others talking about Oracle Java SE licensing changes (Google search)

Tags

JDK bundle contains lots of unnecessary for Docker image stuff, so it was cleaned up. There are 3 tags: *-full (only src tarballs get removed), *-cleaned (desktop parts get cleaned), *-slim (everything but compiler and jvm is removed). master branch refers to jdk8-slim tag, but latest tag points to jdk8-cleaned.

jdk8-slim (master branch) download image size is:

jdk8-cleaned (latest tag) download image size is:

jdk8-full download image size is:

Consider using jre* tags of this image if you only need JRE (you can run Java applications, but cannot build/compile them):

jre8-slim (master branch) download image size is:

jre8-cleaned (latest tag) download image size is:

jre8-full download image size is:

Usage Example

$ echo 'public class Main { public static void main(String[] args) { System.out.println("Hello World"); } }' > Main.java
$ docker run --rm -v "$(pwd)":/mnt --workdir /mnt frolvlad/alpine-java:jdk8-slim sh -c "javac Main.java && java Main"

Once you have run this command you will get printed 'Hello World' from Java!

Tips

Use Docker multi-stage builds to slim down your final Docker images:

FROM frolvlad/alpine-java:jdk8-slim AS builder

RUN echo 'public class Main { public static void main(String[] args) { System.out.println("Hello World"); } }' > Main.java
RUN javac Main.java

FROM frolvlad/alpine-java:jre8-slim
COPY --from=builder /Main.class /

CMD ["java", "Main"]

$ docker build -t my-app .
$ docker run --rm my-app
Hello World

Your application image is going to be only 119MB on disk.