Summary

Remove the final modifier from the method VarHandle::isAccessModeSupported to allow the implementation subclass to override and provide an alternative implementation.

Problem

VarHandle::isAccessModeSupported anticipates a VarHandle's VarForm to have implementation member names, which doesn't necessarily exist for non-direct VarHandle implementations. Thus IndirectVarHandle::isAccessModeSupported throws NullPointerException on its invocation.

Solution

Make VarHandle::isAccessModeSupported non-final to allow subclasses to override and provide a subclass-specific implementation.

Specification

@@ -2120,7 +2118,7 @@ public abstract sealed class VarHandle implements Constable
      * @return {@code true} if the given access mode is supported, otherwise
      * {@code false}.
      */
-    public final boolean isAccessModeSupported(AccessMode accessMode) {
+    public boolean isAccessModeSupported(AccessMode accessMode) {
         return vform.getMemberNameOrNull(accessMode.ordinal()) != null;
     }