Merge pull request #1563 from ropalka/UNDERTOW-2353

[UNDERTOW-2353] A few adjustments to make Undertow build and test on JDK21

Author: fl4via

.github/workflows/ci.yml

@@ -59,7 +59,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
         module: [core, servlet, websockets-jsr]
-        jdk: [11, 17]
+        jdk: [11, 17, 21]
         openjdk_impl: [ temurin ]
     steps:
     - name: Update hosts - linux

core/src/main/java/io/undertow/util/HeaderValues.java

@@ -581,4 +581,8 @@ public boolean addAll(final Collection<? extends String> c) {
         }
         return !c.isEmpty();
     }
+
+    public HeaderValues reversed() {
+        throw new UnsupportedOperationException();
+    }
 }

pom.xml

@@ -87,8 +87,9 @@
         <spotbugs.exclude.filter.file>../spotbugs-exclude.xml</spotbugs.exclude.filter.file>
 
         <!-- Surefire args -->
+        <modular.jdk.props></modular.jdk.props>
         <surefire.jpda.args/>
-        <surefire.system.args>-ea ${surefire.jpda.args} -Xmx1024m</surefire.system.args>
+        <surefire.system.args>-ea ${surefire.jpda.args} -Xmx1024m ${modular.jdk.props}</surefire.system.args>
         <!--by default run all tests-->
         <test.categories>io.undertow.testutils.category.UnitTest OR NOT io.undertow.testutils.category.UnitTest</test.categories>
 
@@ -632,6 +633,15 @@
                 <module>karaf</module>
             </modules>
         </profile>
-    </profiles>
 
+        <profile>
+            <id>jdk18</id>
+            <activation>
+                <jdk>[18,)</jdk>
+            </activation>
+            <properties>
+                <modular.jdk.props>-Djava.security.manager=allow</modular.jdk.props>
+            </properties>
+        </profile>
+    </profiles>
 </project>