Update to 16-ea+5

16/jdk/alpine/Dockerfile

@@ -0,0 +1,39 @@
+FROM alpine:3.11
+
+RUN apk add --no-cache java-cacerts
+
+ENV JAVA_HOME /opt/openjdk-16
+ENV PATH $JAVA_HOME/bin:$PATH
+
+# https://jdk.java.net/
+# > Java Development Kit builds, from Oracle
+ENV JAVA_VERSION 16-ea+5
+ENV JAVA_URL https://download.java.net/java/early_access/alpine/5/binaries/openjdk-16-ea+5_linux-x64-musl_bin.tar.gz
+ENV JAVA_SHA256 1ec940bea148a7ececda635c209de3836fe4e6511f5d49d4248cf6d52c77aac8
+# "For Alpine Linux, builds are produced on a reduced schedule and may not be in sync with the other platforms."
+
+RUN set -eux; \
+	\
+	wget -O /openjdk.tgz "$JAVA_URL"; \
+	echo "$JAVA_SHA256 */openjdk.tgz" | sha256sum -c -; \
+	\
+	mkdir -p "$JAVA_HOME"; \
+	tar --extract --file /openjdk.tgz --directory "$JAVA_HOME" --strip-components 1; \
+	rm /openjdk.tgz; \
+	\
+# https://github.com/docker-library/openjdk/issues/212#issuecomment-420979840
+# https://openjdk.java.net/jeps/341
+	java -Xshare:dump; \
+	\
+# see "java-cacerts" package installed above (which maintains "/etc/ssl/certs/java/cacerts" for us)
+	rm -rf "$JAVA_HOME/lib/security/cacerts"; \
+	ln -sT /etc/ssl/certs/java/cacerts "$JAVA_HOME/lib/security/cacerts"; \
+	\
+# basic smoke test
+	java --version; \
+	javac --version
+
+# https://docs.oracle.com/javase/10/tools/jshell.htm
+# https://docs.oracle.com/javase/10/jshell/
+# https://en.wikipedia.org/wiki/JShell
+CMD ["jshell"]