de.caff.generics.util

Interface IReference<T>

Type Parameters:

T - type of referenced object

All Known Implementing Classes:

CopyRef, HardReferenceImpl, MutableRef, SoftReferenceImpl, WeakReferenceImpl

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface IReference<T>

A reference to an object. This is similar to Reference, but implemented as an interface to also allow hard references and more.

Author:

Rammi

Field Summary

Fields

Modifier and Type	Field and Description
static IReference<?>	NULL_REF Null reference.

Method Summary

Modifier and Type	Method and Description
T	get() Get the referenced object.
static <R> IReference<R>	hard(R obj) Get a hard reference.
default boolean	isNull() Is this the null reference?
static <R> IReference<R>	nullRef() Get a null reference.
static <R> IReference<R>	soft(R obj) Get a soft reference.
static <R> IReference<R>	weak(R obj) Get a weak reference.

Field Detail

NULL_REF

static final IReference<?> NULL_REF

Null reference. This always returns null on get(). Use nullRef() instead to avoid compiler warnings.

Method Detail

get

@Nullable
T get()

Get the referenced object. Depending on the implementation this might return null if the referenced object is garbage collected or this is a null reference.

Returns:

referenced object, or null

isNull

default boolean isNull()

Is this the null reference? Don't override this method.

Returns:

true: this is the null reference, so returning null is its purpose
false: this is not the null reference, so returning null means the original object is garbage collected and gone to object nirvana

nullRef

@NotNull
static <R> IReference<R> nullRef()

Get a null reference.

Type Parameters:

R - referenced type

Returns:

null reference which is always returning null

hard

@NotNull
static <R> IReference<R> hard(@Nullable
                                       R obj)

Get a hard reference.

Type Parameters:

R - referenced type

Parameters:

obj - object to be referenced

Returns:

hard reference

soft

@NotNull
static <R> IReference<R> soft(@Nullable
                                       R obj)

Get a soft reference. This returns a reference which keeps the referenced object via a SoftReference.

Type Parameters:

R - referenced type

Parameters:

obj - object to be referenced

Returns:

soft reference

weak

@NotNull
static <R> IReference<R> weak(@Nullable
                                       R obj)

Get a weak reference. This returns a reference which keeps the referenced object via a WeakReference.

Type Parameters:

R - referenced type

Parameters:

obj - object to be referenced

Returns:

weak reference