Class AccessibleObjectHandlerJDK9Plus

java.lang.Object
ognl.AccessibleObjectHandlerJDK9Plus
All Implemented Interfaces:
AccessibleObjectHandler
class AccessibleObjectHandlerJDK9Plus extends Object implements AccessibleObjectHandler
Utilizes a JDK 9 and later mechanism for changing the accessibility level of a given AccessibleObject.

If the JDK 9+ mechanism fails, this class will fall back to a standard pre-JDK 9 reflection mechanism. Note: That may cause "WARNING: Illegal reflective access" output to be generated to stdout/stderr.

For reference, this class draws on information from the following locations: - Post about Illegal Reflective Access what is an illegal reflective access - Blog on Unsafe Java Magic. Part 4: sun.misc.Unsafe - Blog on Unsafe Guide to sun.misc.Unsafe - JEP about access to Unsafe being retained in JDK 9 JEP 260: Encapsulate Most Internal APIs

In addition to the above, inspiration was drawn from Gson: PR 1218, PR 1306.

Appreciation and credit to the authors, contributors and commenters for the information contained in the preceding links.

Since:
3.1.24

  • Field Details

    • CLAZZ_UNSAFE

      private static final Class<?> CLAZZ_UNSAFE

    • UNSAFE_INSTANCE

      private static final Object UNSAFE_INSTANCE

    • UNSAFE_OBJECT_FIELD_OFFSET_METHOD

      private static final Method UNSAFE_OBJECT_FIELD_OFFSET_METHOD

    • UNSAFE_PUT_BOOLEAN_METHOD

      private static final Method UNSAFE_PUT_BOOLEAN_METHOD

    • ACCESSIBLE_OBJECT_OVERRIDE_FIELD

      private static final Field ACCESSIBLE_OBJECT_OVERRIDE_FIELD

    • ACCESSIBLE_OBJECT_OVERRIDE_FIELD_OFFSET

      private static final long ACCESSIBLE_OBJECT_OVERRIDE_FIELD_OFFSET

  • Constructor Details

    • AccessibleObjectHandlerJDK9Plus

      private AccessibleObjectHandlerJDK9Plus()
      Private constructor

  • Method Details

    • unsafeOrDescendant

      static boolean unsafeOrDescendant(Class<?> clazz)
      Package-accessible method to determine if a given class is Unsafe or a descendant of Unsafe.
      Parameters:
      clazz - the Class upon which to perform the unsafe check.
      Returns:
      true if parameter is Unsafe or a descendant, false otherwise

    • instantiateClazzUnsafe

      private static Class<?> instantiateClazzUnsafe()
      Instantiate an instance of the Unsafe class.
      Returns:
      class if available, null otherwise

    • instantiateUnsafeInstance

      private static Object instantiateUnsafeInstance()
      Instantiate an instance of Unsafe object.
      Returns:
      instance if available, null otherwise

    • instantiateUnsafeObjectFieldOffsetMethod

      private static Method instantiateUnsafeObjectFieldOffsetMethod()
      Instantiate an Unsafe.objectFieldOffset() method instance.
      Returns:
      method if available, null otherwise

    • instantiateUnsafePutBooleanMethod

      private static Method instantiateUnsafePutBooleanMethod()
      Instantiate an Unsafe.putBoolean() method instance.
      Returns:
      method if available, null otherwise

    • instantiateAccessibleObjectOverrideField

      private static Field instantiateAccessibleObjectOverrideField()
      Instantiate an AccessibleObject override field instance.
      Returns:
      field if available, null otherwise

    • determineAccessibleObjectOverrideFieldOffset

      private static long determineAccessibleObjectOverrideFieldOffset()
      Attempt to determine the AccessibleObject override field offset.
      Returns:
      field offset if available, -1 otherwise

    • createHandler

      static AccessibleObjectHandler createHandler()
      Package-level generator of an AccessibleObjectHandlerJDK9Plus instance.

      Not intended for use outside of the package.

      Note: An AccessibleObjectHandlerJDK9Plus will only be created if running on a JDK9+ and the environment flag is set. Otherwise this method will return an AccessibleHandlerPreJDK9 instance instead,

      Returns:
      an AccessibleObjectHandler instance
      Since:
      3.1.24

    • setAccessible

      public void setAccessible(AccessibleObject accessibleObject, boolean flag)
      Utilize accessibility modification mechanism for JDK 9 (Java Major Version 9) and later. Should that mechanism fail, attempt a standard pre-JDK9 accessibility modification.
      Specified by:
      setAccessible in interface AccessibleObjectHandler
      Parameters:
      accessibleObject - the AccessibleObject upon which to apply the flag.
      flag - the new accessible flag value.