com.google.common.collect

Interface Interner<E>

@Beta
 @GwtIncompatible
public interface Interner<E>

Provides equivalent behavior to String.intern() for other immutable types. Common implementations are available from the Interners class.

Since:

3.0

Author:

Kevin Bourrillion

Method Summary

Modifier and Type	Method and 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