Also support Java 21 (#743)

Co-authored-by: Ben Madore <ben.madore@glassdoor.com>

bin/docker-setup.sh

@@ -15,7 +15,7 @@ rm gradle.zip
 mv /opt/gradle/*/* /opt/gradle
 
 # pre-install JDK for all major versions
-for JVM_VERSION in 17 11 8
+for JVM_VERSION in 21 17 11 8
 do 
   coursier java --jvm $JVM_VERSION --jvm-index https://github.com/coursier/jvm-index/blob/master/index.json -- -version
 done

bin/scip-java-docker-script.sh

@@ -3,7 +3,7 @@
 # version. It assumes that `coursier` is available on the `$PATH` and that the
 # `scip-java` binary is already installed at `/app/scip-java/bin/scip-java`.
 set -eu
-JVM_VERSION="${JVM_VERSION:-17,11,8}"
+JVM_VERSION="${JVM_VERSION:-21,17,11,8}"
 FILE="$PWD/lsif-java.json"
 if test -f "$FILE"; then
 	FROM_CONFIG=$(jq -r '.jvm' "$FILE")
@@ -23,12 +23,11 @@ do
 	if [ "$LAST_CODE" != "0" ]; then
 		echo "Using JVM version '$JVM_VERSION'"
 
-		if [ "$JVM_VERSION" = "17" ]; then
+		if [ "$JVM_VERSION" = "17" ] || [ "$JVM_VERSION" = "21" ]; then
 			export JAVA_OPTS="--add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED"
 		else
 			export JAVA_OPTS=""
 		fi
-
 		eval "$(coursier java --jvm "$JVM_VERSION" --env --jvm-index https://github.com/coursier/jvm-index/blob/master/index.json)"
 
 		java -version

docs/getting-started.md

@@ -54,6 +54,10 @@ docker run -v $(pwd):/sources --env JVM_VERSION=11 sourcegraph/scip-java:latest
 
 # Java 17 (default)
 docker run -v $(pwd):/sources --env JVM_VERSION=17 sourcegraph/scip-java:latest scip-java index
+
+# Java 21
+docker run -v $(pwd):/sources --env JVM_VERSION=21 sourcegraph/scip-java:latest scip-java index
+
 ```
 
 ### Java launcher