Caffeine cache 3.1.8 · com.github.benmanes.caffeine.cache.Interner

Provides similar behavior to String#intern for any immutable type.

Note that String.intern() has some well-known performance limitations and should generally be avoided. Prefer Interner#newWeakInterner or another Interner implementation even for String interning.

Method Summary

Modifier and Type	Method and Description
public E	Returns: the representative instance, possibly the `sample` if absent intern(E the element to add if absent sample) Chooses and returns the representative instance for any collection of instances that are equal to each other.
public static < the type of elements E> Interner<E>	Returns: an interner for retrieving the canonical instance newStrongInterner() Returns a new thread-safe interner that retains a strong reference to each instance it has interned, thus preventing these instances from being garbage-collected.
public static < the type of elements E> Interner<E>	Returns: an interner for retrieving the canonical instance newWeakInterner() Returns a new thread-safe interner that retains a weak reference to each instance it has interned, and so does not prevent these instances from being garbage-collected.

Method Detail

intern back to summary

intern	back to summary
public E intern(E sample) Chooses and returns the representative instance for any collection of instances that are equal to each other. If two equal inputs are given to this method, both calls will return the same instance. That is, `intern(a).equals(a)` always holds, and `intern(a) == intern(b)` if and only if `a.equals(b)`. Note that `intern(a)` is permitted to return one instance now and a different instance later if the original interned instance was garbage-collected. Warning Do not use with mutable objects. Parameters sample:E the element to add if absent Returns:E the representative instance, possibly the `sample` if absent Exceptions NullPointerException: if `sample` is null

public E intern(E sample)

Chooses and returns the representative instance for any collection of instances that are equal to each other. If two equal inputs are given to this method, both calls will return the same instance. That is, intern(a).equals(a) always holds, and intern(a) == intern(b) if and only if a.equals(b). Note that intern(a) is permitted to return one instance now and a different instance later if the original interned instance was garbage-collected.

Warning

Do not use with mutable objects.

Parameters

sample:E: the element to add if absent

Returns:E

the representative instance, possibly the sample if absent

Exceptions

NullPointerException:: if sample is null

newStrongInterner	back to summary
public static <E> Interner<E> newStrongInterner() Returns a new thread-safe interner that retains a strong reference to each instance it has interned, thus preventing these instances from being garbage-collected. Parameters <E> the type of elements Returns:Interner<E> an interner for retrieving the canonical instance

newStrongInterner

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public static <E> Interner<E> newStrongInterner()

Returns a new thread-safe interner that retains a strong reference to each instance it has interned, thus preventing these instances from being garbage-collected.

Parameters

<E>: the type of elements

Returns:Interner<E>

an interner for retrieving the canonical instance

newWeakInterner	back to summary
public static <E> Interner<E> newWeakInterner() Returns a new thread-safe interner that retains a weak reference to each instance it has interned, and so does not prevent these instances from being garbage-collected. Parameters <E> the type of elements Returns:Interner<E> an interner for retrieving the canonical instance

newWeakInterner

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public static <E> Interner<E> newWeakInterner()

Returns a new thread-safe interner that retains a weak reference to each instance it has interned, and so does not prevent these instances from being garbage-collected.

Parameters

<E>: the type of elements

Returns:Interner<E>

an interner for retrieving the canonical instance

public Interface Interner<E>

Method Summary

Method Detail