Add java 21+ support

packages/java/20.0.1/build.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+# Put instructions to build your package in here
+
+curl "https://download.java.net/java/GA/jdk20.0.1/b4887098932d415489976708ad6d1a4b/9/GPL/openjdk-20.0.1_linux-x64_bin.tar.gz" -o java.tar.gz
+
+tar xzf java.tar.gz --strip-components=1
+rm java.tar.gz
+

packages/java/20.0.1/environment

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+# Put 'export' statements here for environment variables
+export PATH=$PWD/bin:$PATH

packages/java/20.0.1/metadata.json

@@ -0,0 +1,5 @@
+{
+    "language": "java",
+    "version": "20.0.1",
+    "aliases": []
+}

packages/java/20.0.1/run

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+# Put instructions to run the runtime
+mv $1 $1.java
+filename=$1.java
+shift
+java $filename "$@"

packages/java/20.0.1/test.java

@@ -0,0 +1,5 @@
+public class HelloWorld {
+    public static void main(String[] args) {
+        System.out.println("OK");
+    }
+}