Class ImplLookupAccessor

java.lang.Object

dev.derklaro.reflexion.internal.handles.ImplLookupAccessor

final class ImplLookupAccessor
extends Object

An accessor to get the IMPL_LOOKUP field using the unsafe field methods provided by the jvm.

Since:

1.0

Constructor Summary

Constructors

Modifier	Constructor	Description
private	ImplLookupAccessor()

Method Summary

Modifier and Type	Method	Description
static @Nullable MethodHandles.Lookup	findImplLookup()	Tries to get the IMPL_LOOKUP using the either direct field access or the methods provided by sun.misc.Unsafe.
private static @Nullable MethodHandles.Lookup	tryResolveUsingDirectAccess()	Tries to resolve the IMPL_LOOKUP field by direct access, only available on a modern jvm if unnamed modules were granted access to the java.lang.invoke module.
(package private) static @Nullable MethodHandles.Lookup	tryResolveUsingUnsafeAccessibleObject()	Tries to resolve the IMPL_LOOKUP field using the methods provided by sun.misc.unsafe.
(package private) static @Nullable MethodHandles.Lookup	tryResolveUsingUnsafeGetObject()	Tries to resolve the IMPL_LOOKUP field using the methods provided by sun.misc.unsafe.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ImplLookupAccessor

private ImplLookupAccessor()

Method Details

findImplLookup

@Nullable
public static @Nullable MethodHandles.Lookup findImplLookup()

Tries to get the IMPL_LOOKUP using the either direct field access or the methods provided by sun.misc.Unsafe.

Returns:

the IMPL_LOOKUP field value or null if the lookup is not possible.

tryResolveUsingDirectAccess

@Nullable
private static @Nullable MethodHandles.Lookup tryResolveUsingDirectAccess()

Tries to resolve the IMPL_LOOKUP field by direct access, only available on a modern jvm if unnamed modules were granted access to the java.lang.invoke module.

Returns:

the IMPL_LOOKUP instance, resolved via direct field access or null if not possible.

tryResolveUsingUnsafeGetObject

@VisibleForTesting
@Nullable
static @Nullable MethodHandles.Lookup tryResolveUsingUnsafeGetObject()

Tries to resolve the IMPL_LOOKUP field using the methods provided by sun.misc.unsafe. This method only works on a sun jvm and will most likely stop working in further releases of the jvm (20/21/22...) as all methods which are returning field offsets were deprecated and will be removed.

Returns:

the IMPL_LOOKUP instance, resolved using sun.misc.unsafe or null if not possible.

tryResolveUsingUnsafeAccessibleObject

@VisibleForTesting
@Nullable
static @Nullable MethodHandles.Lookup tryResolveUsingUnsafeAccessibleObject()

Tries to resolve the IMPL_LOOKUP field using the methods provided by sun.misc.unsafe. This method only works on a sun jvm and tries to force-override the accessible state of the IMPL_LOOKUP field.

Returns:

the IMPL_LOOKUP instance or null if not possible.

Since:

1.6