Package com.google.common.collect

Interface Interner<E>

@Beta
@DoNotMock("Use Interners.new*Interner")
@GwtIncompatible
public interface Interner<E>

Provides similar behavior to String.intern() for any immutable type. Common implementations are available from the Interners class.

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

Since:

3.0

Author:

Kevin Bourrillion

Method Summary

Modifier and Type	Method	Description
E	intern(E sample)	Chooses and returns the representative instance for any of a collection of instances that are equal to each other.

Method Detail

intern

@CanIgnoreReturnValue
E intern(E sample)

Chooses and returns the representative instance for any of a 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.

Throws:

NullPointerException - if sample is null