Use reflection to invoke getCommentTree to support Java 21 & 23

Fixes #4540

rewrite-java-21/src/main/java/org/openrewrite/java/isolated/ReloadableJava21ParserVisitor.java

@@ -44,6 +44,7 @@
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.Name;
 import java.lang.reflect.Field;
+import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.nio.file.Path;
 import java.util.*;
@@ -1664,7 +1665,10 @@ private <J2 extends J> J2 convert(Tree t) {
         try {
             String prefix = source.substring(cursor, max(((JCTree) t).getStartPosition(), cursor));
             cursor += prefix.length();
-            @SuppressWarnings("unchecked") J2 j = (J2) scan(t, formatWithCommentTree(prefix, (JCTree) t, docCommentTable.getCommentTree((JCTree) t)));
+            // Java 21 and 23 have a different return type from getCommentTree; with reflection we can support both
+            Method getCommentTreeMethod = DocCommentTable.class.getMethod("getCommentTree", JCTree.class);
+            DocCommentTree commentTree = (DocCommentTree) getCommentTreeMethod.invoke(docCommentTable, (JCTree) t);
+            @SuppressWarnings("unchecked") J2 j = (J2) scan(t, formatWithCommentTree(prefix, (JCTree) t, commentTree));
             return j;
         } catch (Throwable ex) {
             // this SHOULD never happen, but is here simply as a diagnostic measure in the event of unexpected exceptions