Refactored Dockerfile to use SDKMAN. Reconfigured Java, Gradle, & Maven versioning to be controlled by SDKMAN

Author: tw29845

images/java/ubuntu.Dockerfile

@@ -1,52 +1,23 @@
 FROM codercom/enterprise-base:ubuntu
 
-# Run everything as root
-USER root
-
-ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64
-ENV PATH=$PATH:$JAVA_HOME/bin
-ENV DEBIAN_FRONTEND=noninteractive
-
-# Install JDK (OpenJDK 21)
-RUN apt-get update -y \
-  && apt-get install openjdk-21-jdk -y --no-install-recommends --no-install-suggests
-
-# Install Maven
-ARG MAVEN_VERSION=3.9.11
-ARG MAVEN_SHA512=bcfe4fe305c962ace56ac7b5fc7a08b87d5abd8b7e89027ab251069faebee516b0ded8961445d6d91ec1985dfe30f8153268843c89aa392733d1a3ec956c9978
-
-ENV MAVEN_HOME=/usr/share/maven
+ENV DEBIAN_FRONTEND="noninteractive"
+ENV JAVA_VERSION="21.0.8-tem"
+ENV GRADLE_VERSION="8.14.3"
+ENV MAVEN_VERSION="3.9.11"
 ENV MAVEN_CONFIG="/home/coder/.m2"
 
-RUN mkdir -p $MAVEN_HOME $MAVEN_HOME/ref \
-  && echo "Downloading Maven" \
-  && curl -fsSL -o /tmp/apache-maven.tar.gz https://dlcdn.apache.org/maven/maven-3/${MAVEN_VERSION}/binaries/apache-maven-${MAVEN_VERSION}-bin.tar.gz \
-  && echo "Checking downloaded file hash" \
-  && echo "${MAVEN_SHA512} /tmp/apache-maven.tar.gz" | sha512sum -c - \
-  && echo "Unzipping Maven" \
-  && tar -xzf /tmp/apache-maven.tar.gz -C $MAVEN_HOME --strip-components=1 \
-  && echo "Cleaning and setting links" \
-  && rm -f /tmp/apache-maven.tar.gz \
-  && ln -s $MAVEN_HOME/bin/mvn /usr/bin/mvn
-
-# Install Gradle
-ENV GRADLE_VERSION=8.14.3
-ARG GRADLE_SHA512=517ed3a20fe9f14f8c7e34778f5d248c61473e2b67e48a6d3341682a4bdcab502723f1d985fbb9e7f360a74a4e15f113d08a515bcc7b56dd5eb426f8e2cf82bf
-
-ENV GRADLE_HOME=/usr/bin/gradle
-
-RUN mkdir -p /usr/share/gradle /usr/share/gradle/ref \
-  && echo "Downloading Gradle" \
-  && curl -fsSL -o /tmp/gradle.zip https://services.gradle.org/distributions/gradle-${GRADLE_VERSION}-bin.zip \
-  && echo "Checking downloaded file hash" \
-  && echo "${GRADLE_SHA512} /tmp/gradle.zip" | sha512sum -c - \
-  && echo "Unzipping Gradle" \
-  && unzip -q -d /usr/share/gradle /tmp/gradle.zip \
-  && echo "Cleaning and setting links" \
-  && rm -f /tmp/gradle.zip \
-  && ln -s /usr/share/gradle/gradle-${GRADLE_VERSION} /usr/bin/gradle
-
-ENV PATH=$PATH:$GRADLE_HOME/bin
-
-# Set back to coder user
-USER coder
+RUN sudo apt-get update && \
+  sudo apt-get install --yes --no-install-recommends --no-install-suggests zip && \
+  curl -fsSL "https://get.sdkman.io" | bash && \
+  source "/home/coder/.sdkman/bin/sdkman-init.sh" && \
+  sdk version && \
+  sdk install java $JAVA_VERSION && \
+  sdk default java $JAVA_VERSION && \
+  sdk install gradle $GRADLE_VERSION && \
+  sdk default gradle $GRADLE_VERSION && \
+  sdk install maven $MAVEN_VERSION && \
+  sdk default maven $MAVEN_VERSION && \
+  sdk flush && \
+  sdk current java && \
+  sdk current gradle && \
+  sdk current maven